HomeMy WebLinkAbout3-B_Stormwater-Resource-Plan-for-the-Tahoe-Sierra-RegionSTORMWATER RESOURCE PLAN FOR THE
TAHOE-SIERRA REGION
February 28, 2018Prepared for Tahoe Resource Conservation District by
Funding has been provided in full or in part through an agreement with the
State Water Resources Control Board using funds from Proposition 1. The
contents of this document do not necessarily reflect the views and policies
of the foregoing, nor does mention of trade names or commercial products
constitute endorsement or recommendation for use.
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TABLE OF CONTENTS
TABLE OF CONTENTS .............................................................................................................................. 2
ACRONYMS ............................................................................................................................................ 4
EXECUTIVE SUMMARY ............................................................................................................................ 5
INTRODUCTION .................................................................................................................................... 10
IMPLEMENTERS .............................................................................................................................................. 11
PARTNERS ...................................................................................................................................................... 11
OTHERS ........................................................................................................................................................... 12
SECTION A. DESCRIPTION OF WATERSHED AND SUB-WATERSHEDS .................................................... 13
WATERSHED BOUNDARIES (SWRP GUIDELINES SECTION A.I) ................................................................ 13
INTERNAL BOUNDARIES (SWRP GUIDELINES SECTION A.II) .................................................................... 13
WATER QUALITY PRIORITIZATION (SWRP GUIDELINES SECTION A. III)................................................... 22
SURFACE AND GROUNDWATER QUALITY (SWRP GUIDELINES SECTION A. IV) .................................. 25
WATER SUPPLY (SWRP GUIDELINES SECTION A.V) .................................................................................. 30
NATIVE HABITATS (SWRP GUIDELINES SECTION A. VI) ............................................................................ 31
WATERSHED PROCESSES (SWRP GUIDELINES SECTION A.VII) ............................................................... 33
SECTION B. ORGANIZATION, COORDINATION & COLLABORATION .................................................. 35
IRWM PARTNERSHIP (SW RP GUIDELINES SECTION B.I & B.VI) ................................................................ 35
SWRP STAKEHOLDERS (SWRP GUIDELINES SECTION B.II & B.III) ............................................................. 35
REQUIRED DECISIONS (SWRP GUIDELINES SECTION B.V) ...................................................................... 37
OTHER CONSIDERATIONS (SWRP GUIDELINES SECTION B.IV & B.VII)................................................... 37
SECTIONS C&D METHODS & PROJECT PRIORITIZATION ....................................................................... 38
TAHOE IDENTIFICATION OF PROJECTS (SWRP GUIDELINES SECTION C.1) .......................................... 38
TAHOE METRICS-BASED ANALYSIS (SWRP GUIDELINES SECTION C.2) ................................................. 39
TAHOE GUIDANCE FOR PRIORITIZING PROJECTS (SWRP GUIDELINES SECTION D.1)........................ 41
TAHOE WATER QUALITY ANALYSIS (SWRP GUIDELINES SECTION C.2.A) ............................................. 42
TAHOE MULTIPLE BENEFITS (SWRP GUIDELINES SECTION D.2) ............................................................... 43
TAHOE DATA MANAGEMENT (SWRP GUIDELINES SECTION C.3) ......................................................... 43
NON-TAHOE IDENTIFICATION OF PROJECTS (SWRP GUIDELINES SECTION C.1) ................................ 44
NON-TAHOE METRICS-BASED ANALYSIS (SWRP GUIDELINES SECTION C.2) ....................................... 44
NON-TAHOE GUIDANCE FOR PRIORITIZING PROJECTS (SWRP GUIDELINES SECTION D.1) ............. 46
NON-TAHOE WATER QUALITY ANALYSIS (SWRP GUIDELINES SECTION C.2.A) ................................... 48
NON-TAHOE MULTIPLE BENEFITS (SWRP GUIDELINES SECTION D.2) ..................................................... 49
NON-TAHOE DATA MANAG EMENT (SWRP GUIDELINES SECTION C.3) ............................................... 49
SECTION E. PLAN IMPLEMENTATION STRATEGY AND SCHEDULING OF PROJECTS ............................. 50
RESOURCES FOR PLAN I MPLEMENTATION (SWRP GUIDELINES SECTION E.1) ..................................... 50
IMPLEMENTATION PROGRAM (SWRP GUIDELINES SECTION E.2) ......................................................... 50
ADAPTIVE MANAGEMENT (SWRP GUIDELINES SECTION E.3) & PERFORMANCE MEASURES (SWRP
GUIDELINES SECTION E.4) ........................................................................................................................... 52
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SECTION F. EDUCATION, OUTREACH, AND PUBLIC PARTICIPATION ................................................... 56
PUBLIC EDUCATION & PARTICIPATION (SWRP GUIDELINES SECTION F.I & F.II) .................................. 56
AFFECTED COMMUNITIES (SWRP GUIDELINES SECTION F.III) ................................................................. 56
SPECIFIC AUDIENCES (SWRP GUIDELINES SECTION F.IV & F.V) ............................................................ 56
ENVIRONMENTAL INJUSTICE (SWRP GUIDELINES SECTION F.VI) ........................................................... 57
ENGAGEMENT & COMMUNICATION SCHEDULE (SWRP GUIDELINES SECTION F.VII) ....................... 57
APPENDIX A – COMMUNI TY WATER SUPPLIERS
APPENDIX B – CDPH REGULATED WATER SYSTEMS
APPENDIX C – 303D LISTED WATERBODIES
APPENDIX D – TAHOE METRIC INFORMATION SHEETS
APPENDIX E – RANKED PROJECT LISTS FOR TAHOE PROJECTS
APPENDIX F – METRIC AND BENEFIT ESTIMTATES FOR EACH TAHOE PROJECT
APPENDIX G – NON-TAH OE METRIC INFORMATION SHEETS
APPENDIX H – RANKED PROJECT LISTS FOR NON-TAHOE PROJECTS
APPENDIX I – METRIC AND BENEFIT ESTIMATES FOR EACH NON-TAHOE PROJECT
APPENDIX J – EXPECTED PROJECT FUNDING NEED
APPENDIX K – SWRP TRACKER PRODUCTS
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ACRONYMS
BMP Best management practices
CDFW California Department of Fish and Wildlife
CDPH California Department of Public Health
CEQA California Environmental Quality Act
CTC California Tahoe Conservancy
CWA Clean Water Act
CWD County Water District
DAC Disadvantaged Community
DWR Department of Water Resources
EI Environmental Injustice
EIP Environmental Improvement Program
FSP Fine Sediment Particle
HU Hydrologic Unit
IRWM Integrated Regional Water Management
IRWMP Integrated Regional Water Management Plan
Lahontan RWQCB Water Quality Control Board Lahontan Region
MCL Maximum Contaminant Levels
MTBE Methyl tert-butyl ether
MUN Municipal and Domestic Supply
NGO Non-governmental Organizations
NPDES National Pollutant Discharge Elimination System
PCB Polychlorinated Biphenyls
PCWA Placer County Water Agency
PLRM Pollutant Load Reduction Model
PLRP Pollutant Load Reduction Plan
PM Performance Measures
PUD Public Utility District
Region Tahoe-Sierra Region
SEZ Stream Environment Zones
SMCL Secondary Maximum Contaminant Level
SWRP Stormwater Resource Plan
SWMP Stormwater Management Program
State Water Board California State Water Resources Control Board
TAC Technical Advisory Committee
Tahoe-basin Lake Tahoe Basin
Tahoe RCD Tahoe Resource Conservation District
TDS Total Dissolved Solid
TMDL Total Maximum Daily Load
TN Total Nitrogen
TP Total Phosphorous
TRPA Tahoe Regional Planning Agency
USEPA US Environmental Protection Agency
USFS US Forest Service
UST Underground Storage Tank
WEPD Washoe Environmental Protection Department
Water Boards State Water Resources Control Board and Regional Water Quality Control Boards
Water Code Water Code…
WDR Waste Discharge Requirement
WQO Water Quality Objective
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EXECUTIVE SUMMARY
Water Code §10563(c)(1), requires a Stormwater Resource Plan (SWRP) as a condition of receiving funds
for stormwater and dry weather runoff capture projects from any bond approved by voters after January
2014. Th e Tahoe-Sierra SWRP was developed according to the SWRP Guidelines which provide baseline
requirements for SWRPs. The SWRP Guidelines state that traditional approaches to stormwater
management have focused on implementation of management practices and limited treatment prior to
conveyance off-site and ultimately into surface waters. Traditional approaches do not fully address the
water quality impacts from stormwater discharges while providing multiple benefits such as water supply
augmentation and ecological enhancement of the local watershed. More recent watershed-based
approaches to stormwater management seek to replicate natural hydrology and watershed processes by
managing stormwater and dry weather runoff onsite or within the watershed where rainfall occurs. These
watershed-based approaches yield multiple water quality benefits by reducing the volume of runoff
delivered to receiving waters, thus reducing the pollutants discharged. Watershed-based approaches to
stormwater management also yield non-measurable social and community benefits that traditional projects
do not provide.1
CHARACTERISTICS OF THE REGION
The SWRP applies to the same geographic region as
the Tahoe-Sierra Integrated Regional Water
Management Plan (IRWMP). To achieve the multi-
benefit goals of the plan, it is necessary to recognize
and tailor the SWRP to the unique characteristics of
this Region such as, differentiating between project
implementers within and outside of the Tahoe-basin s.
Additionally, it is important to recognize which
benefit types are meaningful to prioritize based on the
Region’s resources and needs.
Tahoe vs. Non-Tahoe Jurisdictions
Jurisdictions and projects within the Region are
separated into two groups, those within the Tahoe-
basin, and those outside of the Tahoe-basin, but both
are still within the Tahoe-Sierra Region (Region)
(Figure 1). Jurisdictions within the Tahoe-basin (Tahoe
jurisdictions) have made significant investments in
developing quantitative project benefit estimates
through regulatory requirements to use analysis tools
such as the Pollutant Load Reduction Model (PLRM),
Geographic Information System (GIS) and other
technical methods. In comparison, jurisdictions
outside the Tahoe-basin (Non -Tahoe jurisdictions)
have not had the same requirements to motivate
model development or load tracking. As a result, it is
necessary to develop two sets of metrics for estimating
project benefits and ranking them.
1 State Water Resources Control Board. (2015, November 16). Storm Water Resource Plan Guidelines. Retrieved from
http://www.waterboards.ca.gov/water_issues/programs/grants_loans/swgp/docs/draft_guidelines_120315.pdf
Tahoe
Non-Tahoe
Figure 1. Map showing the geographic extent of the Tahoe and
Non-Tahoe portions of the SWRP region.
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Benefit Categories
In order for stormwater resource projects within this region to be eligible for grant funds, the project must
achieve benefits across multiple categories such as water quality, community, flood management, and the
environment. For example, a project that increases green space, involves the community, and reduces
sediment would be a multi-benefit project. Although SWRP Guidelines identify five benefit categories, the
SWRP includes only four of these categor ies because water supply is not a priority concern within the
Region. Stakeholders and implementers are focused on obtaining benefits to protect water quality, improve
the environment, community, and provide flood management benefits. In addition, public utility districts
(PUDs) project reliable drinking sources into the future (Water Code §10562(d)(1)). As a result, the
remaining four benefit categories (water quality, flood management, environmental, and community) are
used to identify benefits and rank projects (Figure 2).
Figure 2. Grey boxes indicate the four benefit categories included in the SWRP multi-benefit analysis. Projects must provide benefits
in two categories to qualify as multi-benefit.
GUIDANCE FOR RANKING PROJECTS
For proposed projects to be eligible for funding, they must be ranked on the SWRP project list. Ranking
projects, including them on the list, and ensuring they meet the minimum eligibility requirements requires
several steps. Project implementers are responsible for the following portion of the ranking process:
1. Select project metrics
a. Review available project information.
b. Based on the information available, select relevant metrics for each project (Table 1). Each
project must use one or more metrics in 2+ benefit categories to be considered multi-
benefit.
c. Check project information against the information sheet (info sheet) and critical definitions
to ensure the metric is being used appropriately (Appendix D).
2. Estimate project benefits
a. Select the appropriate range and associated score for each metric (Table 2) based on best
professional judgement, knowledge of past projects, or by developing quantitative
estimates.
3. Check minimum requirements are met
a. Project uses at least one metric from 2+ benefit categories.
b. Project includes a valid benefit estimate.
Tahoe Resource Conservation District (Tahoe RCD) manages implementation and adaptive management
of the SWRP including updating the ranked project list. Because the project lists are publicly available,
implementers can submit project data to Tahoe RCD at any time, but Tahoe RCD will only review and
finalize this data on an annual basis. Once implementers provide their project data, Tahoe RCD scores
projects to develop the ranked project list as shown in the following steps:
4. Score projects (Figure 3)
a. Average the points for each benefit category if a project is using multiple metrics within
one benefit category.
b. Sum the points across benefit categories.
5. Rank projects based on their score
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Figure 3. Project scoring method. Light grey boxes are metric scores within each benefit category (dark grey boxes). Light blue
boxes show that metrics within each benefit category are averaged and then summed to determine the total project score (dark
blue box).
Metrics for ranking projects and estimating benefits
The following tables show the metrics implementers use to quantify the multiple benefits of their
stormwater projects. The steps implementers should follow to apply these metrics to their projects are
described in the “Guidance for ranking projects” section above. Separate sets of metrics are intended for
use by Tahoe (Table 1) and Non-Tahoe (Table 2) jurisdictions based on the differing characteristics of these
regions. The expected aggregate benefit of all planned projects on the SWRP project list is described in
Section s C&D.
Table 1. Guidance for estimating Tahoe-basin benefits
2 The ranges for each metric intentionally overlap so that project implementers have flexibility when selecting point values for their
project. This is intended to reflect that benefit estimates are preliminary and likely to adjust as projects develop.
3 Best Management Practice (BMP)
4 Disadvantaged Community (DAC)
METRIC NAME BENEFIT
CATEGORY UNITS POINTS 2
0 1 2 3 4 5
1 - Fine sediment load
reduction Water Quality Pounds/yr 0 1 to 1000 900 to 2400 2200 to 3500 3100 to 4900 4400+
2 - Nitrogen load reduction Water Quality Pounds/yr 0 1 to 5 3 to 9 7 to 13 11 to 20 18+
3 - Phosphorous load
reduction Water Quality Pounds/yr 0 1 to 18 16 to 30 27 to 50 45 to 70 65+
4 - Parcels with stormwater
BMPs 3 Water Quality Number 0 1 to 4 3 to 60 50 to 130 100 to 360 300+
5 - Linear feet of stream
channel restored or enhanced Environment Linear ft. 0 1 to 150 100 to 400 350 to 600 550 to 1000 800+
6 - Acres of habitat restored or
enhanced Environment Acres 0 0.1 to 1 0.5 to 2 1.5 to 6 5 to 15 12+
7 - Facilities improved or
created Community Number 0 1 to 2 2 to 3 3 to 4 4 to 5 5+
8 - Tahoe DAC4 population
served Community No Yes
9 - Community areas
enhanced or created Community No Yes
10 - Volume of stormwater
reduced, stored or infiltrated Flood M gmt. Acre Feet/yr 0 0.25 to 1 0.75 to 1.5 1.25 to 2.25 2 to 3 2.75+
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Table 2. Guidance for estimating non-Tahoe benefits
METRIC NAME BENEFIT
CATEGORY
POINTS 5
0 1 2 3 4 5
11 - Drains to TMDL6 waterbody Water Quality No Yes
12 - Provides source control for
stormwater pollutant Water Quality No Yes
13 - Pollutant load reduction Water Quality No All other
pollutants 303(d) listed
pollutant Approved TMDL
pollutant
14 - Volume of stormwater treated Water Quality 0 0.1-0.8 Af/yr 0.7 – 1.2 Af/yr 1.1 – 1.6 Af/yr 1.5 - 2 Af/yr >1.9 Af/yr
15 - Total suspended solid load
reduction Water Quality <1,000 lb/yr 750-6,000 lb/yr 5,000-12,000 lb/yr 10,000-30,000 lb/yr 25,000-50,000 lb/yr 45,000+ lb/yr
16 - Parcels with stormwater
BMPs Water Quality 0 1 to 4 3 to 60 50 to 130 100 to 360 300+
17 - Project restores, enhances, or
creates habitat Environment No Yes Listed species Endangered
species
18 - Stream channel restored,
enhanced, or created Environment No Yes Listed species Endangered
species
19 - Non-Tahoe DAC population
served Community No Yes
20 - Employment opportunity
created Community No Short -term Long-term
21 - Enhance or create community
areas Community No Yes
22 - Project improves property
values Community No Yes
23 - Proximity to flood-prone
channel Flood Mgmt. not in subbasin >1 miles 0.75mile – 0.25mile 0.3mile – 0.1mile 0.15mile – 75yds <100yds
24 - Runoff reduced through
storage or infiltration Flood Mgmt. No
Yes, but
flooding is not a
problem locally
Yes, minor
flooding locally Yes, major
flooding locally
25 - Impervious area reduced (%) Flood Mgmt. <30% 25% - 45% 40% - 60% 55% - 75% 70% - 90% 85% – 100%
26 - Natural hydrology/
hydrograph reestablished Flood Mgmt. No Yes
5 The ranges for each metric intentionally overlap so that project implementers have flexibility when selecting point values for their project , reflecting that benefit estimates are preliminary.
6 Total Maximum Daily Load (TMDL)
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ADAPTIVE MANAGEMENT
The SWRP follows an adaptive management process consisting of four steps (Figure 4) that enable the plan
to stay relevant and enhance the potential for new funding sources. This process enables (1) implementers
to revise their project list so new projects are eligible for funding and (2) the advisory committee to adjust
metric lists so they remain useful as new information is gained or regulatory requirements are updated.
The public is invited to provide input as well.
Figure 4. Four steps of the adaptive management process (blue polygons) and SWRP products (icons in circles). This process is
anticipated to take place every other year.
The adaptive management process of the S WRP follows several steps:
1. Tracking & Reporting Performance: project implementers report initi al benefit estimates,
implement their projects and then report benefits for completed projects . Reporting benefit
estimates at both project stages provides implementers feedback on the accuracy of their initial
estimates, leading to better future estimates, funders’ increasing confidence in estimates, and
a greater likelihood of receiving future funding.
2. Synthesizing Findings: estimated benefits are aggregated across projects to indicate the
magnitude of expected benefit to the region and estimate progress toward regulatory targets.
Additionally, the metric lists are reviewed to determine if they are still relevant and useful.
3. Recommending Adjustments: updates to the metric lists are proposed and reviewed by the
Technical Advisory Committee (TAC) and public during a meeting. Decisions made during
the meeting are captured in a meeting report.
4. Adopting & Implementing Adjustments: using the revised metric list, the SWRP project list
is updated.
CHANGES TO THE SWRP
Many sections of the SWRP document don’t require updates over time and therefore remain static. For
example, updates to Section A descriptions of watershed characteristics are unlikely to be necessary or
beneficial. In comparison, updates to the project list can be submitted at any time and are reviewed and
approved on an annual basis. As a result of the adaptive management process, specific components of the
SWRP such as the list of metrics may be updated every two years. The following table summarizes which
components of the SWRP are likely to change, may change, and which are unlikely to change (Table 3):
Table 3. Likelihood of SWRP components to change over time
LIKELY TO CHANGE MAY CHANGE UNLIKELY TO CHANGE
Project lists & data Metric lists SWRP document sections
A, B, E, F Benefit estimates Metric ranges
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INTRODUCTION
The SWRP for the Tahoe-Sierra Integrated Regional Water Management (IRWM ) Region is organized into
five sections (Figure 5). Each section contains the information necessary to meet SWRP Guidelines and
Water Code requirements and is tailored to the characteristics of the Region.
Figure 5. The primary content of sections A through F of the document are represented by a graphic and brief description (grey text).
Section A states that the SWRP region matches the Region so that existing planning efforts can be
leveraged to the maximum extent possible. Additionally, sub-watershed boundaries within the Region are
identified along with water quality regulations and impairments. This information is helpful context for
decisions about benefit categories and metrics selected.
Section B identifies the responsibilities of the implementers, partners, and other stakeholders participating
in SWRP development and implementation. Collaborating with these entities may lead to joint solutions
to address obstacles inherent in watershed-scale stormwater management and helps to maximize benefits
to natural resources, the community and the economy. This section is used to discover who is involved in
delivering stormwater projects and making decisions.
Sections C&D outline the process for jurisdictions to propose their projects and benefit estimates for each
project. The process for ranking each project list and determining the aggregate benefit of all listed projects
is also described. The aggregate of project benefit estimates indicates progress toward meeting regulatory
requirements, like water quality regulations. Due to the unique characteristics of the Region, separate
guidance and metrics are developed for the Tahoe-basin and outside of the Tahoe-basin. Although all
jurisdictions may use best professional judgement to provide benefit estimates for planned projects, Tahoe
projects may have additional technical resources available, like the PLRM.
Section E guides adaptive management of the SWRP to ensure clear roles and procedures that maintain
the project list, track progress toward regulatory requirements and update metrics. Pollutant load
reduction targets within the Tahoe-basin are adjusted every 5 years when new municipal stormwater
permits are adopted. A meaningful yet achievable adaptive management process ensures implementers
remain eligible for funding over time as regulatory requirements change, and benefit priorities shift.
Section F identifies opportunities for public education and engagement during development of the SWRP
including a public forum, open TAC meetings and a webpage where materials relevant to SWRP
development are accessible to the public. Public participation during the development and implementation
of the SWRP helps optimize the community-based benefits of watershed scale stormwater management.
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USER GUIDE
This user guide is designed to help users of the SWRP to find the most relevant sections of the document
quickly. This guide is organized by user type including: implementers, partners , and other groups as
defined below.
IMPLEMENTERS
Implementers are local municipalities or organizations within the Region who apply for bond funding to
implement stormwater projects. The SWRP is one of several methods for implementers to prioritize their
projects and support funding decisions. When reviewing the SWRP, implementers should focus on specific
sections of the document which are likely to be most relevant to their needs and interests (Table 4).
Table 4. Examples of SWRP content relevant to project implementers
PARTNERS
Partners are agencies that regulate, fund and oversee the implementation of stormwater programs or
projects. When reviewing the SWRP, partners should focus on specific sections of the document which are
likely to be most relevant to their needs and interests (Table 5).
USER TYPE EXAMPLE USERS NEED FOCUS
Project
implementers
City of South Lake Tahoe
Town of Truckee
South Tahoe PUD
Tahoe Regional Planning
Agency (TRPA)
Truckee River Watershed
Council
Alpine Watershed Group
El Dorado County
Placer County
Alpine County
California Tahoe
Conservancy (CTC)
Tahoe RCD
Understand the steps for adding projects to the
SWRP list
Understand project requirements for funding
eligibility
Decide project multi-benefits
Section C
Section D
Appendices
E, F, H, I
Understand the adaptive management process
▫ how metrics may be revised over time
▫ role/ participation in the process
Section E
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Table 5. Examples of SWRP content relevant to project partners
OTHERS
Other groups may include non-governmental organizations (NGOs ) and universities who have an interest
in the development and implementation of the SWRP. When reviewing the SWRP, these groups should
focus on specific sections of the document which are likely to be most relevant to their needs and interests
(Table 6).
Table 6. Examples of SWRP content relevant to other groups
7 California State Water Resources Control Board (State Water Board)
USER TYPE EXAMPLE USERS NEED FOCUS
Plan
reviewer State Water Board7
Determine whether
▫ SWRP Guidelines are addressed
▫ Water Code requirements are met
Water Code and SWRP
Guideline references
Ex: (SWRP Guidelines
Section A.i)
Ex: Water Code section
10565(c)
Local
Regulator
Water Quality Control
Board Lahontan Regional
(Lahontan RWQCB)
Confirm description of regional
characteristics and existing regulations
is accurate
Section A
Agency
familiar with
local
conditions
TRPA
CTC
Ensure the SWRP builds on,
compliments, and does not conflict
with existing plans
▫ Understand how existing metrics
are leveraged
Sections C&D
▫ Understand how IRWM information
is repurposed instead of recreated IRWM references
USER TYPE EXAMPLE USERS NEED FOCUS
Researchers
& universities
UN Reno, Desert Research
Institute
UC Davis, Tahoe
Environmental Research
Center
Identify any inconsistencies between metric
definitions and current scientific knowledge
Metrics in
Appendices
D & G
Local NGOs League to Save Lake
Tahoe
Understand the methods and opportunities
for public participation throughout
development, implementation and adaptive
management of the SWRP
Section F
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SECTION A. DESCRIPTION OF WATERSHED AND SUB-WATERSHEDS
Section A of the SWRP identifies the SWRP boundary for the Region, watershed and sub-watershed
boundaries within the Region, and water quality regulations and impairments within the major
watersheds, including pollutants identified on the 303(d) list of impaired water bodies or with relevant
TMDLs. Additionally, jurisdictions and projects are separated into two groups, those within the Tahoe-
basin, and those outside of the Tahoe-basin, but both are still within the Region.
WATERSHED BOUNDARIES (SWRP GUIDELINES SECTION A.I)
The watershed boundaries for the SWRP are the watersheds used in the Tahoe-Sierra IRWMP and include
the following five hydrologic units (HU) (i.e., watersheds): West Fork of the Carson River, East Fork of the
Carson River, Lake Tahoe, Truckee River, and Little Truckee River (Figure 6). It is appropriate for these
five watersheds which comprise the planning region used for the IRWMP to constitute the boundary for
the SWRP becaus e the IRWMP was also developed using a watershed -based approach in order to
implement multi-benefit projects. The SWRP builds from the IRWMP’s multi-benefit watershed approach.
The watersheds of the SWRP are consistent with SWRP Guidelines Section A. 1 through 5 and Water Code
§10565(c) and 10562(b)(1) given that:
the watersheds are the union of several 12-hydrologic unit code watersheds, and are larger than 5
square miles; a scale suitable for quantitative analysis of stormwater and dry weather runoff
patterns,
the watersheds are regional boundaries that allow for comprehensive integrated stormwater
management as they did previously during IRWMP development, and
the watersheds contain multiple jurisdictions (City and County lands) to promote regional
planning, and are not designed to single out a particular project.
INTERNAL BOUNDARIES (SWRP GUIDELINES SECTION A.II)
Internal boundaries within the watershed provide information about the following:
1. Opportunities to augment local water supply through groundwater recharge or storage for
beneficial use of stormwater and dry weather runoff.
2. Opportunities for source control for both pollution and stormwater and dry weather runoff
volume, onsite and local infiltration, and use of stormwater and dry weather runoff.
3. Projects to reestablish natural water drainage treatment and infiltration systems, or mimic natural
system functions to the maximum extent feasible.
4. Opportunities to develop, restore, or enhance habitat and open space through stormwater and dry
weather runoff management, including wetlands, riverside habitats, parkways, and parks.
5. Opportunities to use existing publicly owned lands and easements, including, but not limited to,
parks, public open space, community gardens, farm and agricultural preserves, school sites, and
government office buildings and complexes, to capture, clean, store, and use stormwater and dry
weather runoff either onsite or offsite.
Section A.II of the SWRP Guidelines requires the SWRP document to describe internal boundaries within
the watersheds, preferably in GIS format. The internal boundaries required by the SWRP Guidelines and
pursuant to Water Code §10562(d) are illustrated in GIS format in the SWRP by the following figures and
table:
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Figure 6. Munic ipal boundaries
Figure 7. Land use agencies
Figure 8. Water and wastewater service areas
Figure 9, Figure 10, and Figure 11 Groundwater basin boundaries and watersheds
Table 8. Land ownership in the Region
Municipal and county boundaries
The SWRP boundary includes multiple municipalities and counties including two incorporated cities and
several other communities within portions of Sierra, Nevada, Placer, El Dorado, and Alpine Counties in
California, as shown in Figure 6 and Table 7.
Table 7 Cities and communities in the SWRP Region
Land use agencies
The boundaries of land ownership and the jurisdiction of land use agencies are needed to help identify and
prioritize stormwater projects on public lands pursuant to Water Code §10562(b)(8), (d)(4), and (d)(5).
Furthermore, distribution and location of public, private, and managed lands helps prioritize use of public
lands for stormwater and dry weather runoff projects. Land ownership and distribution of lands managed
by land use agencies are described in Section 2.4.1 of the IRWMP and detailed in Table 8 and Figure 7 of
the SWRP. The Region includes over 800,000 acres, approximately 68% is comprised of public land, 21% is
private land, and 11% is Lake Tahoe. Approximately 80% of the total area in the Region is open space,
including both public and private lands.
Table 8 Land Ownership in the Region
8 US Forest Service (USFS)
COUNTY INCORPORATED CITIES COMMUNITIES
El Dorado City of South Lake
Tahoe
Tahoma, Meyers
Nevada Town of Truckee Donner Lake Village, Floriston
Placer Alpine Meadows, Carnelian Bay, Homewood, Kings Beach,
Olympic Valley, Tahoe City, Tahoe Vista
Alpine Markleeville, Mesa Vista, Alpine Village, Washoe Tribe’s
Woodfords Community, Kirkwood
Sierra West outskirts of Verdi
AGENCY ACREAGE IN REGION PERCENT OF TOTAL AREA
USFS 8 507,530 63%
Bureau of Land Management 18,730 2%
California State Parks 7,000 0.9%
California Department of Fish and Game 6,280 0.8%
State Lands Commission 5,400 0.7%
Other (Military, other State, Federal) 4,700 0.6%
TOTAL STATE AND FEDERAL LANDS 549,600 68%
OTHER (PRIVATE) 167,370 21%
LAKE TAHOE (WITHIN CALIFORNIA) 85,300 11%
!
!
!
!
!
!
!
!
Washoe Tri be'sOlympic Valley Tribal Parcel
LakeTahoe
D o nner La k e
Donner L ake
FallenLeafLake
SouthLakeTahoe
Wa s h o e Tri b e 'sSacramento A llotm ents
Wa s h o e Tri b e 'sBabbit Pe a k Pa rc e l
Wa s h o e Tri b e 'sWoodfords C o m m u n i t y
A L P I N EAMADOR
C A L A V E R A S
E L D O R A D O
M O N O
N E V A D A
P L A C E R
S I E R R A
T U O L O M N E
CarnelianBay
Homewood
AlpineMeadows
Markleeville
Alpine Village
L I T T L ETRUCKE ERIVER
T R U C K E E R I V E R
E A S T F O R KCARSONRIVER
W E S T F O R KCARSONRIVER
L A K E TA H O E
S T O R M W A T E R
R E S O U R C E S
P L A N
R E G I O N
¯0 6Miles
!Point of InterestSWRP WatershedWashoe Tribe Community & Parcels
Stor mwa ter Resource Pla n RegionCounty
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016Figure 6 Map showing relevant boundaries in the Region
0 100 200mi.
SWRP Region
!
!
!
!
!
!
!
!
Lake Tahoe
Fallen Leaf Lake
Donner Lake
ALPINEAMADOR
CALAVERAS
EL DORADO
MONO
NEVADA
PLACER
SIERRA
TUOLOMNE
Sug ar PinePoint SP
Donner Memorial SP
Grover Hot S pring s SP
D L Bliss SP
Tahoe SP
Turtle RockCounty Park
Carnelian Bay
Homewood
Alpine Meadows
Markleeville
South Lake Tahoe
Alpine Village
!Point of InterestCountiesState Park
State and Fed eral Land OwnershipBIABLMCDFW
DODCA Parks and RecLocal GovernmentNon-Profit Lands
Other Federal LandsOther State LandsUSDA Forest Service
L A N D -U S E
A G E N C I E S
Figure 7 Map showing land use agencies in the Region
0 100 200mi.
SWRP Region
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016
¯0 6Miles
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 17
TAHOE-SIERRA REGION
Service areas of water supply and wastewater utilities
Water suppliers in the Region range from small private water systems to larger public districts including
those listed below. Figure 8 shows water suppliers and community and non -community water systems,
which are numbered on Figure 8 and listed numerically in Appendix A and Appendix B of the SWRP
(Appendix 2-A of the Tahoe Sierra IRWMP) (Section 2.4.3, IRWMP).
North Tahoe PUD
South Tahoe PUD
Squaw Valley Public Service District
Tahoe City PUD
Truckee Donner PUD
Placer County Water Agency (PCWA)
Markleeville PUD
Wastewater utilities exist in the Region in addition to the PUDs listed above.
Northstar Sanitary District
Truckee Sanitary District
Alpine Springs County Water District (Alpine Springs CWD)
Groundwater basin boundaries
Groundwater is a primary source of drinking water and a resource in the Region. Groundwater basin
boundaries normally help identify opportunities to “augment local water supply through groundwater recharge
or storage for beneficial use of stormwater and dry weather runoff” Water Code §10562(d)(1). The SWRP is not
tracking the water supply benefits of projects based on feedback from local stakeholders stating it is not a
high priority or focus for the Region. The Department of Water Resources has defined several groundwater
basins in the Region, the Tahoe Valley Basin which is divided in to three subbasins (Tahoe Valley North,
Tahoe Valley West, and Tahoe Valley South (Figure 9)), the Martis Valley Basin, Olympic Valley Basin
(Figure 10), and the Carson Valley Basin (Figure 11). The general quality of groundwater in the Region is
discussed in the Groundwater quality section of the SWRP.
!(
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A L P I N EAMADOR
C A L A V E R A S
E L D O R A D O
N E V A D A
P L A C E R
S I E R R A
T U O L O M N E
AlpineMeadows
CarnelianBay
Homewood
Markleeville
SouthLakeTahoe
Alpine Village
A
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F
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44 4547
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29, 54, 55, 61, 74
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64
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58, 72
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85
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888990 91
92
93
94
97
98
W A T E R A N D
W A S T E W A T E R
S E R V I C E
A R E A S
0 100 200mi.
SWRP Region
Figure 8 Water and Wastewater Service Areas in the Region
!Point of Interest
!(Com munity CDPH SystemNon-Community CDPH Sys. (Appendix pg.)Stormwater Resource Plan RegionCounty
Water System Service AreasMarkleeville P.U.D.Alpin e Sprin gs C oun ty W.D.Lakeside Mutu al Wa terLukins Bros. Water Co.North Tah oe P.U.D.Northstar C.S.D.
So uth Tah oe P.U.D.Squaw Valley W.D.Ta ho e C ity P.U.D.Ta ho e Keys Water Co.Ta lm ont Reso rt I.D.Truckee-Do nn er P.U.D.
#
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service (May, 2016)
¯0 6Miles
!
!
!
!
!
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M
artisCreekPoleCreek
C o ld Creek
G e n eral Creek
U
p
p
erTru
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e
River
S
a
xt
o
nCreek
HeavenlyVal l e y C r e e k
I ndianCreek
L A K E T A H O EWATERSHED
T A H O E V A L L E YWEST G WSUBBASIN
T A H O E V A L L E YNORTH G WSUBBASIN
T A H O E V A L L E YSOUTH G WSUBBASIN
Ca r n el ia nBay
Ho m e w oo d
D o nnerLake
Al p in eMeadows
F a l l e nLeaf L a k e
A l p i n e V i l l a g e
A L P I N E
E L D O R A D O
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016, DWR 2003
!Point of InterestStream SWRP Wat ershedCounty Gro undwa ter Ba si nsTahoe NorthTahoe S outhTahoe West
¯0 3Miles
G R O U N D W A T E R
B A S I N S I N T H E
L A K E T A H O E
W A T E R S H E D
LakeTahoe
0 100 200mi.
SWRP Region
Figure 9 Groundwater basins in the Lake Tahoe Watershed
!
!
!
!
Lake Ta h o e
NorthBranchD
o
g
C
r
e
e
k
M
e
rrill
C
r
e
e
k
Davies C r e e k
ColdStream
N o r t h F o r k P rosserCreek
AlderCree k
TroutCreek
C old Creek
M
a
rtisCreek
P o l e C r e e k
Ward Creek
Homewood
O L Y M P I CVALLEYGW B A S I N
MA RT ISVALLEYGW B A SI N
N E V A D A
P L A C E R
S I E R R A
Carnelian Bay
Donner Lake
Alpine Meadows
L I T T L E T R U C K E E R I V E RWATERSHED
T R U C K E E R I V E RWATERSHED
L A K E T A H O EWATERSHED
!Point of InterestStream CountySWRP Watershed Gr oundw ater BasinsMartis ValleyOlympic ValleySOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016, DWR 2003
¯0 3Miles
G R O U N D W A T E R B A S I N S I N T H E
T R U C K E E A N D L I T T L E T R U C K E E
W A T E R S H E D S
0 100 200mi.
SWRP Region
Figure 10 Groundwater basins in the Truckee and Little Truckee Watersheds
!
!
!
S
a
xo
nCreek
Upper
Tru
c
k
e
e
R
iver
S a wmillCreek
S p r a t t Creek
IndianCreek
B
a
r
n
e
y
R
il
e
y
C
r
e
ek
CharityValleyCreek
P e n n sylv a niaCreek
D i x o n C r e e k
MountainCr
e
ek
C
o
yoteValleyC
r
e
e
k
CarsonValleyGW Basin
Alpine Village
E A S T F O R KCARSON R I V E RWATERSHED
W E S T F O R KCARSON R I V E RWATERSHED
L A K E T A H O EWATERSHED
A L P I N E
E L D O R A D O
M O N O
T U O L U M N E
Markleeville
South Lake Tahoe G R O U N D W A T E R B A S I N
I N E A S T A N D W E S T
F O R K C A R S O N
R I V E R W A T E R S H E D S
!Point of InterestCountySWRP Watershed
Gr oun d wa t er BasinCarson Valley
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016, DWR 2003
¯0 1.5 3Miles
Figure 11 Groundwater basins in the West and East Fork Carson Watersheds
0 100 200mi.
SWRP Region
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 22
TAHOE-SIERRA REGION
WATER QUALITY P RIORITIZATION (SWRP GUIDELINES SECTION A. III)
SWRP Guidelines Section A.III requires a description of the water quality priorities within the watershed
including applicable TMDLs and Clean Water Act (CWA), s ection 303(d) listed segments, and applicable
National Pollutant Discharge Elimination System (NPDES) and waste discharge requirement (WDR)
permits.
303(d) listings in the Region
According to Section 303(d) of the CWA, once technology-based limits are put into place, the States must
identify and list water segments that are not attaining water quality standards. States are then required to
determine the point and nonpoint sources of pollutants causing impairment at each listed segment (Section
2.11.1 of the IRWMP) (Appendix C). General descriptions of these impairments are described for each HU,
summarized in Table 9 and shown on Figure 12.
Table 9 Number of segments by pollutant, listed alphabetically
Lake Tahoe HU
In the Lake Tahoe HU there are twelve 303(d) listed waterbodies, including the Upper Truckee River and
Lake Tahoe its elf. Pollutants impacting the listed water bodies include nutrients, sediment, iron, chloride,
and pathogens. Sources range from natural processes to urban runoff to mine tailings (Section 2.11.2.1 of
the IRWMP). Elimination of grazing in some parts of the Upper Truckee River watershed have allowed the
Upper Truckee River to be delisted for some of these pollutants (Section 2.11.2.2 of the IRWMP).
Truckee River and Little Truckee River HU
There are five listed waterbodies in the Truckee River HU, including the Truckee River itself (Section
2.11.2.2 of the IRWMP). Pollutants impacting the listed water bodies include sediment and priority
organics. There are no listed waterbodies in the Little Truckee River HU.
East and West Fork Carson River HU
There is one 303(d) listed waterbody in the West Fork Carson River HU, and that is the West Fork Carson
River itself (Section 2.11.2.3 of the IRWMP). There are eight 303(d) listed waterbodies in the East Fork
Carson River HU including the East Fork Carson River. Pollutants impacting the listed waterbodies in the
East and West Fork Carson River HUs include metals, nutrients, pathogens, sediment, TDS, and sulfate.
POLLUTANT # OF LISTED SEGMETNS POLLUTANT # OF LISTED SEGMETNS
Aluminum 7 Low Dissolved Oxygen 1
Ammonia 1 Oxygen, Dissolved 4
Arsenic 10 Polychlorinated Biphenyls (PCB) 3
Boron 3 pH 1
Chlordane 1 Phosphorus 42
Chloride 12
Salinity/ Chlorides /
Total Dissolved Solids (TDS) 4
Copper 1 Sedimentation/Siltation 51
Fecal Coliform 25 Silver 6
Fluoride 2 Sulfates 11
Iron 27 TDS 21
Manganese 11 Total Kjeldahl Nitrogen 1
Mercury 13 Total Nitrogen as N 3
Metals 8 Total Petroleum Hydrocarbons 1
Nitrate 3 Trace Elements 1
Nitrogen 27 Turbidity 6
Oil and Grease 1 Unknown Toxicity 3
!
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!
!
!
!
!
!
T r u c k e e River
S q u a w Creek
W a r d Creek
B
lac
k
wo o d Cr k.
G e n e ralC r k .
T
r
o
u
t
C
reek
C o l
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Cree
k
M
oni t o r Creek
WolfCreek
L
e
viathan
C
r
k
.
Ca
r
s
o
nRiver,
EastFork
AlpineMeadows
Carnelia nBay
Homewood
DonnerLake
FallenLeafLake
Mark leeville
SouthLakeTahoe
Alpine Village
A L P I N E
A M A D O R
C A L A V E R A S
E L D O R A D O
M O N O
N E V A D A
P L A C E R
S I E R R A
T U O L U M N E
SOURCE: ESRI; NCE, SWRCB 2012 303(d), TIGER; IRWM AGOL Feature Service dated May, 2016
!Poi nt of InterestStream Cou ntySWRP Water shed 20 12 30 3 (d ) Imp air ed Rive rs/Streams2012 30 3 (d ) Imp air ed Waterbodies
3 0 3 (d ) I m p a i r e d R i v e r s ,
S t r e a m s a n d W a t e r B o d i e s
0 100 200mi.
SWRP Region
Figure 12 Map of 303(d) listed rivers and streams in the Region shown in yellow
¯0 3 6Miles
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 24
TAHOE-SIERRA REGION
TMDLS in the Region
The SWRP should describe “how it is consistent with and assists in, compliance with TMDL implementation plans
and applicable National Pollutant Discharge Elimination System (NPDES) permits” Water Code §10562(b)(5).
Water quality objectives (WQOs) are the pollutant limits established for a waterbody to protect beneficial
use. TMDLs denote the quantity of the pollutant that can be assimilated by the waterbody and still meet
the WQO. TMDLs determine the key pollutants and assign loads to pollutant sources to address impaired
water bodies. Table 10 summarizes the TMDLs completed in the Region . WQOs in the Region limit the
following constituents: ammonia, coliform bacteria, biostimulatory substances, chemical constituents, total
residual chlorine, color, dissolved oxygen, floating materials, oil and grease, non-degradation of aquatic
communities and populations, pesticides, pH, radioactivity, sediment, settleable materials, suspended
materials, taste and odor, temperature, toxicity, and turbidity.
Table 10 TMDLs in the Region grouped by pollutant type
Lake Tahoe HU
Three TMDLs have been approved in the Lake Tahoe HU as of 2013. A sediment TMDL was approved for
Heavenly Valley Creek in 2002, a sediment TMDL was approved for Blackwood Creek in 2008, and a
sediment and nutrient (nitrogen and phosphorus) TMDL was approved for Lake Tahoe in 2011. In addition
to TMDLs, TRPA has established environmental thresholds, goals and policies, and ordinances directed at
protecting and improving water quality in Lake Tahoe and the Lake Tahoe-basin (Tahoe-basin). WQOs
have also been established for all surface waters in the Lake Tahoe HU, and for specific water bodies. These
include WQOs for TDS, nitrogen, phosphorus, iron, chloride, algal growth potential, biological indicators,
clarity, electrical conductivity, plankton counts, suspended sediment, and transparency.
Truckee River and Little Truckee River HU
Sediment TMDLs have been approved for Squaw Creek (2007), Bronco Creek (2009), Gray Creek (2009),
and the Truckee River (2009). A TMDL for “priority organics” (persistent organic compounds including
pesticides and PCBs) has not yet been developed for Donner Lake. The Lahontan RWQCB has also
established WQOs for all surface waters in the Little Truckee River HU and Truckee River for TDS,
nitrogen, phosphorus, iron, chloride, algal growth potential and species composition. Total nitrogen (TN)
loadings in Cold Creek are being addressed by a USFS restoration project.
East and West Fork Carson River HU
A phosphorus TMDL was approved for Indian Creek Reservoir in 2003. Additionally, metals from historic
mining in Aspen Creek, Bryant Creek, and Leviathan Creek are being addressed through a Comprehensive
Environmental Response, Compensation, and Liability Act or Superfund remediation program and
IMPAIRED WATERBODY POLLUTANT ADOPTION BY LAHONTAN RWQCB APPROVAL BY USEPA
Heavenly Valley Creek Sediments January 2001 Sept 30, 2002
Squaw Creek Sediments April 2006 July 27, 2007
Blackwood Creek Sediments Sediments October 2007 July 11, 2008
Bronco Creek Sediments May 2008 Not provided
Truckee River Sediment May 2008 September 16, 2009
Gray Creek Sediment May 2008 Not provided
Lake Tahoe Sediment Nov 2010 August 17, 2011
Ward Creek Sediment Not provided Not provided
Bridgeport Reservoir Nutrients Not provided Not provided
Crowley Reservoir Nutrients Not provided Not provided
Bodie Creek Metals Not provided Not provided
Donner Lake PCBs Not provided Not provided
Susan River Toxicity Not provided Not provided
Haiwee Reservoir Copper Not provided Not provided
Indian Creek Reservoir Phosphorous July 2002 2003
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 25
TAHOE-SIERRA REGION
ongoing Lahontan RWQCB work with an expected attainment date of 2019. The Lahontan RWQCB has
also established WQOs including TDS, nitrogen, phosphorus, sulfate, boron, algal growth potential,
sodium adsorption ratio, and species composition for all surface waters in the East and West Fork Carson
River HUs as well as some specific water bodies (Section 2.11.3 of the IRWMP).
NPDES permits in the Region
SWRP Guidelines require “identification of applicable permits and descriptions of how they meet all applicable
WDR permit requirements” Water Code §10562(b)(6). Table 11 shows the current NPDES permits within the
Region. The Lahontan RWQCB has authority to implement and enforce the Lake Tahoe TMDL through
NPDES permits issued to the California governmental entities (City of South Lake Tahoe, Placer County,
El Dorado County, and the California Department of Transportation).
Table 11 NPDES permits in the Region
WDR in the Region
WDR for small construction projects, including utility and public works projects, that are conducted in
certain sensitive watersheds of the Region other than the Lake Tahoe HU are regulated under R6T-2003-
0004. This also includes WDRs for minor lake or streambed alteration projects throughout the Region that
are not regulated by the US Army Corps of Engineers under CWA Section 404. Small construction projects
disturbing at least 10,000 square feet of land disturbance, but less than one acre, are required to obtain
coverage under the General Order if they are located in the following watersheds within the Region: Little
Truckee River, Truckee River, West Fork Carson River, and East Fork Carson River. General WDR and
NPDES permits for stormwater runoff associated with marina operations in the Lake Tahoe HU are
regulated under R6T-2016-0038.
SURFACE AND GROUNDWATER QUALITY (SWRP GUIDELINES SECTION A. IV)
Surface water resources
The SWRP should “identify activities that generate or contribute to the pollution of stormwater or dry weather
runoff, or that impair their effective beneficial use” Water Code §10562(d)(7). Many waterbodies in the Region
are considered to be impaired by pollutants including sediment, nutrients, and metals. For the protection
of these waterbodies, quality of runoff is an issue in both urban and undeveloped areas. In urban areas,
stormwater transports sediment and other pollutants from impermeable surfaces into receiving
waterbodies. In undeveloped areas, the wetlands, meadows, and riparian areas that would naturally
provide filtration and removal of sediment and nutrients are in some cases impaired and can no longer
provide that filtration, and may instead contribute to sediment loading in downstream waterbodies
through erosion. Surface water resources are characterized for the five HUs within the Region through
description of the beneficial use (Table 12) and the natural and anthropogenic sources of impairments
leading to regulatory action.
Tables and figures extracted from the IRWMP to summarize key information are re-numbered for the
SWRP based on the order they appear in this document:
PERMIT # DISCHARGE LOCATION
97-03-DWQ Industrial Stormwater General Permit Region
99-08-DWQ Construction Activity Stormwater General Permit Region (outside Lake Tahoe HU)
R6T-2004-0025 Surface Water disposal to Treated Groundwater Region
R6T-2011-0019
R6T-2016-0010
Stormwater Runoff Associated with Construction
Activity Involving Land Disturbance Lake Tahoe HU
R6T-2017-0010 Stormwater/ Urban Runoff Discharge City of South Lake Tahoe,
El Dorado County, Placer County
R6T-2014-0049 Limited Thread Discharge to Surface Water Region
R6T-2016-0038 Stormwater Runoff Associated with Marina Operations Lake Tahoe HU
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 26
TAHOE-SIERRA REGION
Table 14 of the SWRP List of beneficial use by surface water (Table 2-6 of the IRWMP)
Table 14 of the SWRP List of beneficial use by groundwater (Table 2-6 of the IRWMP)
Beneficial uses apply whether the waterbody is perennial or ephemeral, or the flow is intermittent or
continuous. WQOs are assigned to protect those beneficial uses. These beneficial uses and WQOs are used
to identify waterbody impairments and objectives that must be met by discharges to the waterbodies.
Beneficial uses that are common to almost all surface water resources in the Region include municipal and
domestic supply (MUN), and agricultural supply (Table 12) (Section 2.8 from the IRWMP). Contact and
noncontact recreation, fishing, and habitat are beneficial uses designated for nearly all surface water bodies
in the Region. Some individual surface water bodies have additional beneficial uses including freshwater
replenishment; navigation; preservation of biological habitats of special significance; support of habitat
necessary for rare, threatened, or endangered species; migration of aquatic organisms; water quality
enhancement of downstream waters; and flood peak attenuation or flood water storage.
Table 12 List of beneficial use by surface water in the Region
Surface water quality
The Lake Tahoe HU is generally impaired by nutrients and sediments, although other impairments exist.
There are no impairments in the Little Truckee River HU. The Truckee River HU is impaired by sediments
and other organics. The West Fork Carson River HU is impaired by nutrients and pathogens while the East
Fork Carson River HU is primarily impaired by metals. The full list of impaired waterways is included in
Appendix C (Appendix 2-B in the IRWMP) and summarized in Table 13.
BENEFICIAL USE
SURFACE WATER
La
k
e
T
a
h
o
e
H
U
Li
t
t
l
e
T
r
u
c
k
e
e
Ri
v
e
r
H
U
Tr
u
c
k
e
e
R
i
v
e
r
HU
We
s
t
F
o
r
k
C
a
r
s
o
n
Ri
v
e
r
H
U
Ea
s
t
F
o
r
k
C
a
r
s
o
n
Ri
v
e
r
H
U
Municipal and domestic supply
Agricultural supply
Industrial service supply
Groundwater recharge
Freshwater replenishment
Navigation
Hydropower generation
Recreation: water contact
Recreation: noncontact
Commercial and sport fishing
Cold freshwater habitat
Wildlife habitat
Preservation of biological habitats of special significance
Rare, threatened, or endangered species
Migration of aquatic organisms
Spawning, reproduction, and development
Water quality enhancement
Flood peak attenuation or flood water storage
(a) Green squares indicate the beneficial use has been designated for all or nearly all surface water bodies in the HU.
Grey squares indicate 1+ surface water bodies in the HU have that beneficial use designation.
(b) Source: Basin Plan (Lahontan Regional Board 1995, amended 2011)
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 27
TAHOE-SIERRA REGION
Table 13 Pollutants leading to 303(d) listing by HU
Lake Tahoe HU
Scientific research (Swift et al. 2006) points to inorganic fine sediment particles (FSP) less than 16
micrometers in diameter as the primary pollutant of concern impairing Lake Tahoe’s transparency. This
finding is based on the ability of inorganic FSPs to efficiently scatter light and decrease observed
transparency. Additional pollutants of concern include phosphorus and nitrogen, as these nutrients can
stimulate algal growth in Lake Tahoe. Additionally, research (Lahontan RWQCB 2010) identified surface
runoff from developed lands as the most significant source of pollutant loading for FSPs (the primary
pollutant of concern) and phosphorus. Surface runoff from developed lands is estimated to deliver over
70% of the average annual FSP load and roughly 40% of the average annual phosphorus load to Lake Tahoe.
For nitrogen, atmospheric deposition is identified as the most significant source of loading to Lake Tahoe,
contributing 55% of the average annual load.
Truckee River HU
Sources of sediment in the Truckee River HU include natural sources, habitat modification, urban runoff,
recreation, construction and land development, and silviculture. Sources for priority organics in Donner
Lake have not been identified although Donner Lake is 303(d) listed.
East and West Fork Carson River HU
Resource extraction, including mining and silviculture, is a source for metals, sulfate, and sediment in
water. There are many former mines within the Carson River HU that are sources of metals and acid mine
drainage, including the Leviathan Mine, some of which are being actively addressed. Grazing in scrub
lands and riparian areas is a source of nutrients, sediment, and pathogens. Other sources for nutrients
include habitat modification, waste storage and disposal, recreation, and atmospheric deposition. Other
sources for pathogens include recreation. Natural sources also exist for some of the metals, nutrients, and
pathogens.
POLLUTANT CATEGORY
SURFACE WATER
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Nutrients – Nitrogen
Sediments
Metals – Sulfates
Metals – Aluminum
Metals – Iron
Metals – Manganese
Metals – Silver
Pathogens
Salinity - Chloride
Salinity - TDS
Other organics
(a) Grey squares indicate 1+ surface water bodies in the HU have that beneficial use designation.
(b) Source: Basin Plan (Lahontan Regional Board 1995, amended 2011)
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 28
TAHOE-SIERRA REGION
Groundwater resources
Groundwater resources in the Region are characterized through descriptions of beneficial uses and
impairments. In addition to surface water quality concerns, groundwater in some areas is impacted with
naturally-occurring chemicals like arsenic, or man-made contaminants such as methyl tertiary-butyl ether
(MTBE) or chlorinated organic chemicals. Groundwater in the Region has important beneficial uses such
as providing the main source of municipal water.
The Lahontan RWQCB Basin Plan outlines beneficial uses for groundwater basins in the Region.9 Beneficial
uses that are common to almost all basins in the Region include MUN, and agricultural supply (Table 14)
(Section 2.11.3 of the IRWMP). Two of the Region’s groundwater basins also provide industrial service
supply, and one basin provides freshwater replenishment benefits.
Table 14 List of beneficial use by groundwater basin in the Region
Groundwater quality
Groundwat er impairments occur from both natural and anthropogenic sources (Table 15). Naturally
occurring uranium, radon, arsenic, iron and magnesium affect some wells within the Region. In the Tahoe-
basin, the nutrient loading in groundwater flowing into the lake contributes 13% of the annual nitrogen
budget and 15% of the annual phosphorus budget for Lake Tahoe. These loadings are based on average
ambient well concentrations ranging from 0.018 milligrams per liter (mg/l) to 0.35 mg/l for nitrate and 0.005
mg/l to 0.065 mg/l for total phosphorus (TP); and average well concentrations in residential, commercial,
or recreational areas ranging from 0.002 mg/l to 8.7 mg/l nitrate and 0.006 mg/l to 0.6 mg/l for phosphorus
(Army Corps of Engineers 2003). Groundwater well nutrient concentrations are not a concern for drinking
water, compared to the US Environmental Protection Agency (USEPA) Maximum Contaminant Level
(MCL) for drinking water of 10 mg/l for nitrate, but as a contributor to the excess nutrients in Lake Tahoe.
Sources of nitrogen and phosphorus include fertilizers and sewage leaks or residual septic system leachate
that infiltrates to groundwater.
Leaking Underground Storage Tanks (USTs) and other cleanup sites may pose a threat to groundwater,
especially in urban areas. Common groundwater contaminants include aromatic volatile organic
compounds such as benzene, ethylbenzene, toluene, and xylenes found in gasoline, oxygenated ethers such
as MTBE from gasoline, and chlorinated hydrocarbons from dry cleaners or industrial solvent usage
(Section 2.11.3 of the IRWMP).
9 http://www.waterboards.ca.gov/lahontan/water_issues/programs/basin_plan/references.shtml
BENEFICIAL USE
GROUNDWATER
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Agricultural supply
Industrial service supply
Groundwater recharge
Freshwater replenishment
(a) Green squares indicate that the beneficial use has been designated for all or nearly all surface water bodies
in the HU, or for the entire groundwater basin.
(b) Source: Basin Plan (Lahontan Regional Board 1995, amended 2011)
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 29
TAHOE-SIERRA REGION
The SWRCB Geotracker website lists 51 open cleanup sites within the Region, not all of which impact
groundwater. Additionally, there are 80 permitted USTs, and 256 closed sites in the Region. Nearly all of
the cleanup sites are located around Lake Tahoe, in the Town of Truckee, or along Interstate-80. Responsible
parties are addressing these open sites, which include petroleum, MTBE, and chlorinated hydrocarbon
impacts, under the regulatory oversight of the Lahontan RWQCB. Water agencies use treatment and/or
source blending to meet MCLs for water that is delivered to their customers (Section 2.11.3 of the IRWMP).
The Basin Plan assigns WQOs to groundwater for bacteria (coliform), chemical constituents, radioactivity,
and taste and odor. 10
In groundwaters designated as MUN, the median concentration of coliform organisms over any
seven-day period shall be less than 1.1/100 milliliters.
Groundwater designated as MUN shall not contain concentrations of chemical constituents in
excess of the MCL or secondary maximum contaminant level (SMCL) based upon drinking water
standards specified in the following provisions of Title 22 of the California Code of Regulations.
Additionally, waters shall not contain concentrations of chemical constituents that adversely affect
the water for beneficial uses.
Ground waters designated as MUN shall not contain concentrations of radionuclides in excess of
the limits specified in Section 64443 (Radioactivity) of Title 22 of the California Code of
Regulations.
Ground waters shall not contain taste or odor-producing substances in concentrations that cause
nuisance or that adversely affect beneficial uses. For groundwaters designated as MUN, at a
minimum, concentrations shall not exceed adopted SMCLs.
Table 15 Groundwater basin impairments in the Region
IMPAIRMENT
GROUNDWATER
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Uranium
Radon
Arsenic
Iron
Magnesium
TDS
Nutrients
VOCs
(a) Grey squares indicate 1+ surface water bodies in the HU have that beneficial use designation.
(b) Source: Basin Plan (Lahontan Regional Board 1995, amended 2011)
Tahoe Valley South groundwater subbasin
In the Tahoe Valley South groundwater subbasin, uranium, iron, and manganese have been detected in
some wells at concentrations exceeding the respective primary or SMCLs. Arsenic, which is naturally
occurring and has a primary MCL, has also been detected in some wells in the South Lake Tahoe
groundwater subbasin, but at concentrations below the current MCL in all but one well, at which a
treatment system is operating.
10 http://www.waterboards.ca.gov/lahontan/water_issues/programs/basin_plan/references.shtml
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 30
TAHOE-SIERRA REGION
MTBE contamination has impacted several South Tahoe PUD supply wells, requiring inactivation or
reduction in pumping rate, installation of wellhead treatment systems, and pursuit of source area
protection measures (Winzler & Kelley 2011). Some South Tahoe PUD supply wells are also impacted by
chlorinated hydrocarbons, requiring treatment to meet the respective MCLs (Section 2.11.3 of the IRWMP).
Martis Valley groundwater basin
Arsenic affects some Truckee Donner PUD and PCWA groundwater wells in the Martis Valley
groundwater basin, and manganese has been detected above the MCL in a PCWA groundwater well
(Section 2.11.3 of the IRWMP).
Olympic Valley groundwater basin
Arsenic, iron, manganese, and TDS have been detected above the MCLs in monitoring wells in the east part
of the Olympic Valley groundwater basin, but not in the production wells in the west part of the basin
(Section 2.11.3 of the IRWMP).
WATER SUPPLY (SWRP GUIDELINES SECTION A.V)
Section A.V of the Guidelines requires a description of entities that provide potable and non-potable water
supplies in the Region. Section 2.9.1.3 and Table 2-8 in the IRWMP identifies water suppliers and describes
the volume and source. This information is summarized below.
Potable water
In addition to the five major public water districts in the Region (North Tahoe PUD, South Tahoe PUD,
Tahoe City PUD, Truckee Donner PUD, and PCWA Zone 4), there are over twenty smaller community
water suppliers (Appendix A), and over 100 non-community water suppliers and individual property
own ers with groundwater wells listed numerically in Appendix B. Over 90% of the potable water supplied
in the Region is pumped from groundwater, with some limited surface water use from Lake Tahoe, Carson
River, other lakes in the Region, and various springs (Figure 13).
Figure 13 Over 90% of the potable water supply in the Region is from groundwater sources (shown in blue). Each bar shows the
annual water supply from each water supplier in acre-feet.
A majority of potable water in the region is supplied by groundwater. Twenty-year water supply
projections from PUDs in the region indicate a reliable water supply exists in the region (Table 16). Given
groundwater sources are reliable, water purveyors have placed little emphasis on augmenting
groundwater supply by infiltrating stormwater. Groundwater remains an important resource throughout
the region, however for the purposes of the SWRP, stakeholders and implem enters are focused on
obtaining benefits to protect water quality, improve the environment, community, and provide flood
management benefits. As a result, water supply benefits are not included in the SWRP as mentioned
0
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Groundwater Source
Surface water source
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 31
TAHOE-SIERRA REGION
throughout the document. The exception is the Markleeville Mutual Water Company, which requires that
new developments provide wells and increased storage because of difficulties meeting current and
projected demand (Section 2.9.1.3 of the IRWMP).
Table 16 20-year water supply projection in Acre Feet per Year by water supplier in the Region
Non-potable water
There are limited opportunities for additional water reclamation within the Region. The Porter- Cologne
Act requires that all wastewater be exported from the Tahoe-basin with a few min or exceptions. The Porter-
Cologne Act allows for approval of pilot reclamation projects in the Tahoe-basin , but none have been
approved to date (as of July 2014). As a result, all wastewater in the northern part of the Tahoe-basin is
collected by North Tahoe PUD or Tahoe City PUD and transported to T-TSA in Truckee for treatment and
discharge to a d isposal field in Martis Valley. Reclamation of this water for other uses is limited as the
Settlement Act prohibits any reduction in return flow of treated wastewater to the Truckee River without
offset or acquisition of water rights.
In the southern part of the Tahoe-basin , all wastewater is collected by South Tahoe PUD. South Tahoe PUD
treats the wastewater and then pumps it to Alpine County over Luther Pass for storage in Harvey Place
Reservoir and summer irrigation use by area ranches. Approximately 4.5 million gallons per day is pumped
to Harvey Place Reservoir for reuse. In the year 2000, a special legislative act allowed South Tahoe PUD to
install six fire hydrants at the base of the reclaimed water export pipeline to provide fire protection for a
small community in the Lake Valley Fire Protection District service area that does not have municipal water
service.
NATIVE HABITATS (SWRP GUIDELINES SECTION A. VI)
Significant ecological resources contribute to the recreation and tourism of the Region. The waterways
provide habitat for common and sensitive fish, amphibian, and invertebrate species, while the adjacent
terrestrial habitats support numerous bird, mammal, and plant species (Section 2.12 of the IRWMP).
Terrestrial habitats
Table 17 summarizes the terrestrial habitat types for the different HU’s in the Region. (Adapted Table 2-14
of the IRWMP)
Table 17 Percent coverage of land cover types by HU
WATER SUPPLIER YEAR
2015 2020 2025 2030 2035
North Tahoe PUD 1,782 2,138 2,566 3,079 Not provided
South Tahoe PUD 9,528 9,528 9,528 9,528 9,528
Tahoe City PUD 1,458 1,903 1,903 1,903 Not provided
PCWA Zone 4 306 439 573 707 800
LAND COVER LAKE
TAHOE HU
LITTLE TRUCKEE
RIVER HU
TRUCKEE
RIVER HU
WEST FORK CARSON
RIVER HU
EAST FORK
CARSON RIVER HU
% OF
TOTAL
Agriculture 0% 0% 0% 5% 1% 0.7%
Barren/ Other 1% 2% 4% 17% 13% 6.6%
Conifer Forest 44% 74% 63% 39% 43% 51.3%
Conifer Woodland 0% 0% 0% 0% 8% 2.1%
Hardwood Forest 0% 1% 1% 1% 1% 0.7%
Herbaceous 1% 3% 2% 4% 2% 2.2%
Shrub 10% 13% 23% 34% 32% 21.1%
Urban 5% 0% 4% 0% 0% 2.4%
Water 37% 5% 1% 0% 0% 11.9%
Wetland 1% 3% 1% 0% 0% 1%
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 32
TAHOE-SIERRA REGION
The general vegetation zones in the Region are subalpine, upper montane, montane, and sagebrush scrub
in parts of the Carson River HUs. The predominant plant communities in the Region include Jeffrey Pine,
Mixed Conifer, White Fir series, Red Fir series, Lodgepole Pine, and Aspen. At the higher elevations mixed
subalpine forest, Western White Pine, Whitebark Pine, and Subalpine Meadow are common. Big Sagebrush
is common in the lower elevations in the Truckee River and Carson River HUs. Alpine Grassland, Montane
Meadow, and Sedge Meadow are also present (Section 2.12.1 of the IRWMP).
Aquatic habitats
The many creeks, rivers, lakes, and wetlands in the Region provide native riparian and aquatic habitats.
Releases from Prosser Creek, Boca, and Stampede dams support fisheries in the Truckee River and Pyramid
Lake. Vernal pools are found in Martis Valley, supporting sensitive plant species.
The Region is in the historic ranges for the Lahontan Cutthroat Trout and the Paiute Cutthroat Trout, both
of which are federally listed as th reatened species. Currently the Paiute Cutthroat Trout is only found in
Silver King Creek, a tributary to the East Fork Carson River. Populations of the Lahontan Cutthroat Trout
are currently found in the following waters (Ascent Environmental 2 013, The Nature Conservancy 2014):
Upper Truckee River above Meiss Meadows (in the Lake Tahoe HU)
Fallen Leaf Lake/Glen Alpine watershed (in the Lake Tahoe HU)
Lake Tahoe
Pole Creek (in the Truckee River HU)
Truckee River, at Granite Flat Campground
Independence Lake (in the Little Truckee River HU)
East Fork Carson River
Other fish species such as Brook, Rainbow, Brown, and Mackinaw/lake trout, and Kokanee Salmon are also
found in the lakes and rivers of the Region. The California Department of Fish and Wildlife (CDFW) has
named the following waters in the Region as Wild Trout Waters:
Heenan Lake in the East Fork Carson River HU, also named “Heritage Trout Water” for the
Lahontan Cutthroat trout
East Fork Carson River upstream of the confluence with Wolf Creek
East Fork Carson River from Hangman’s Bridge near Markleeville to the Nevada state line
Martis Creek Reservoir
Truckee River, between the confluence with Trout Creek and the confluence with Gray Creek
Upper Truckee River upstream from the confluence with Showers Creek
There are no federally designated wild and scenic rivers in the Region, although there are several stretches
being considered for listing. Approximately 10 miles of the East Fork of the Carson River, between
Markleeville and the California-Nevada border, is designated as a California Wild and Scenic River. This
designation prohibits the construction of dams, reservoirs, and diversion facilities along that stretch of
river. The Region includes parts of the Carson-Iceberg and Mokelumne Wildernesses in the Toiyabe
National Forest, and part of Desolation Wilderness in the El Dorado National Forest and LTBMU. The USFS
has also designated Grass Lake as a Research Natural Area.
In the Tahoe-basin Stream Environment Zones (SEZ) are riparian areas, wetlands, and other areas with a
seasonally high groundwater level and/or surface water. They protect water quality though infiltration,
nutrient uptake, denitrification, and sediment capture. Protection of these areas is vital to the health of the
lakes and rivers receiving the runoff (Section 2.12.2 of the IRWMP).
The terrestrial and aquatic habitats in the Region have potential to support endangered or special status
species. These species are summarized in Table 2-15 of the IRWMP. There are no designated critical habitats
in the Region for the endangered and special status species with potential to occur.
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 33
TAHOE-SIERRA REGION
Parks and open space
Parks and other natural open spaces are shown in Figure 14 of the SWRP. Parks and open spaces include
park lands owned by the California State Parks systems, national forests, and wilderness areas. The
economy in the Region relies heavily on tourism and thus much of the publicly owned open space and
parklands are managed for recreation and tourism.
WATERSHED PROCESSES (SWRP GUIDELINES SECTION A.VII)
Section A.VII of the SWRP Guidelines requires an identification of natural watershed processes and how
those have been disrupted. Understanding how natural watershed processes have been disrupted is
important in understanding how stormwater and dry weather runoff projects can minimize impacts of
urbanization on stormwater and dry weather runoff. Natural watershed processes that influence runoff
include precipitation patterns, infiltration, evaporation, and transpiration. Chapter 1 of the TRPA BMP
Handbook describes the natural watershed processes that influence stormwater runoff in the Region.
Precipitation that falls as snow is stored temporarily in snow pack, and is released as water at varying rates
depending on temperature, wind, solar radiation, and other climatic factors. Because 60 to 70 percent of the
total precipitation in the Lake Tahoe Region falls as snow, hydrologic processes associated with snowmelt
are important in understanding the overall water balance. Although rain and rain-on -snow events typically
produce the highest rates of surface runoff, the amount of surface runoff from rain or snowmelt is affected
by storage of water on the ground surface and in soils, by infiltration at the surface and from the soil into
groundwater, and by losses back to the atmosphere through evaporation and transpiration (Section 1.2.1
of the TRPA BMP Handbook).
Urbanization changes land use in ways that influence stormwater quality and quantity. In a natural
watershed, pervious and vegetated areas intercept and store precipitation through infiltration into the soil,
uptake by vegetation, or storage in depressional features, such as wetlands. Urbanization increases
impervious cover which reduces the amount of precipitat ion intercepted by vegetated areas and infiltrated
into the subsurface. As a result, there are larger volumes of runoff produced, less precipitation is stored in
groundwater and in the subsurface, and higher runoff volumes are transported downstream to receiving
waters. Urbanization thus increases runoff volume and creates flashier systems that can cause or contribute
to erosion, drainage, and flooding.
In addition to its impacts on runoff volumes, urbanization can impact water quality. Impervious surfaces,
such as roads and parking lots, collect pollutants such as copper from brake pads, fine sediment and dirt,
and oil and grease. When runoff travels across these surfaces it collects and transports these pollutant loads
to surface waters. Agricultural land uses also influence stormwater runoff quantity and quality.
Agricultural lands generally have lower infiltration capacity compared to natural lands, higher nutrient
loads, and can be more susceptible to erosion due to the amount of exposed soil.
Urbanization in the Region has had the largest impact on land cover in and around the municipalities
surrounding the Lake Tahoe shoreline, along the Upper Truckee River, and in the Truckee -Donner Region .
These areas have the largest and most contiguous amount of residential and commercial properties
throughout the Region, while the largest and most contiguous agricultural land uses occur in the Truckee
and Carson River watersheds, as shown in Figure 14.
Carnelian Bay
Homewood
Donner Lake
Alpine Meadows
Fallen Leaf Lake
Markleeville
South Lake Tahoe
Alpine Village
A L P I N E
A M A D O R
C A L A V E R A S
E L D O R A D O
M O N O
N E V A D A
P L A C E R
S I E R R A
T U O L U M N E
SOURCE: ESRI; NCE, TIGER; IRWM AGOL Feature Service dated May, 2016, Land Cover 2011
!Point of InterestCountySWRP Watersheds
Open WaterPerennial S now/IceBarren LandCultivated Crops
Dev. Open S paceDev. Low IntensityDev. Med. IntensityDev. High Intensi ty
Shrub/ScrubHay/PastureEvergreen ForestDeciduous Forest
Mixed ForestHerbaceuousEmerg. Herb. Wtlds.Woody Wetlands
L a n d U s e
0 100 200mi.
SWRP Region
Figure 14 Land Use in the Region
¯0 3 6Miles
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 35
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SECTION B. ORGANIZATION, COORDINATION & COLLABORATION
Development and implementation of the SWRP includes participation by local agencies, nongovernmental
organizations, and the broader community Water Code §10565(a)&10562(b)(4). Collaborating with these
entities may lead to joint solutions to address obstacles inherent in watershed scale stormwater
management and helps to maximize benefits to natural and recreational resources, the community and the
economy.
IRWM PARTNERSHIP (SWRP GUIDELINES SECTION B.I & B.VI)
The SWRP involves many of the stakeholders that are members of the IRWM (SWRP Guidelines Section
B.I). There is a history of c ollaboration among these stakeholders and therefore no new or altered
governance structures are required to support collaboration among agencies responsible for SWRP
implementation (SWRP Guidelines Section B.VI).
SWRP S TAKEHOLDERS (SWRP GUIDELINES SECTION B.II & B.I II)
SWRP development is guided by a group of stakeholders referred to as the TAC to ensure the SWRP is
appropriate for the Region and addresses regional stormwater priorities (Table 18). TAC members met
consistently during SWRP development, facilitated by the Tahoe RCD, Environmental Incentives, and
NCE. TAC m embers belong to one of the following three groups:
Facilitators: project funder (Tahoe RCD) and consultants (Env ironmental Incentives and NCE)
who plan and execute TAC meetings as well as develop the SWRP.
Implementers: representatives from local jurisdictions and NGOs who apply for bond funding
to implement stormwater and dry weather runoff capture projects (SWRP Guidelines Section B.II).
Partners: representatives from federal, state, and local agencies that currently support, fund, or
otherwise have an interest in prioritizing stormwater and dry weather runoff capture projects.
Others: parties other than implementers or partners, such as NGOs, who have an interest in the
development and implementation of the SWRP along with the general public (SWRP Guidelines
Section B.III).
The following organizations participated in development and implementation of the SWRP as members of
the TAC:
Table 18. SWRP TAC members
ORGANIZATION STAKEHOLDER GROUP
El Dorado County Implementer
City of South Lake Tahoe Implementer
Alpine County Implementer
Town of Truckee Implementer
State Water Board Partner
Lahontan RWQCB Partner
TRPA Partner
CTC Partner
Desert Research Institute Other
UC Davis Tahoe Environmental Research Center Other
Placer County Implementer
Truckee River Watershed Council Implementer
Sierra County Implementer
League to Save Lake Tahoe Other
Alpine Watershed Group Implementer
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 36
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Implementer: Local jurisdictions
Representatives from the local municipalities are the primary implementers of stormwater projects and
currently comprise the core working members of the TAC (Table 19). Their role is to provide guidance on
the development and implementation of the SWRP to ensure that the SWRP builds on, compliments, and
does not conflict with existing priorities and plans. The responsibilities of the local municipalities include:
Providing relevant existing documents and maps to inform the development of the SWRP;
Providing input on the metrics and analysis process used to prioritize projects;
Reviewing components of the SWRP as they are produced by the development team; and
Participating in collaborative meetings.
Table 19. Representatives from local municipalities
ORGANIZATION
El Dorado County Placer County
City of South Lake Tahoe Truckee River Watershed Council
Alpine County Sierra County
Town of Truckee South Tahoe PUD
Implementer: NGO
Alpine Watershed Group is a local NGO whose role is to add their projects to the SWRP project list and
implement their projects (Table 20).
Table 20. Representative from NGOs
ORGANIZATION
Alpine Watershed Group
Partners: Regional government agencies
Representatives from the regional government agencies in Table 21 are involved in regulating and
overseeing the implementation of stormwater programs or projects by local jurisdictions or permittees.
Their role is also to provide guidance and support in the development and implementation of the SWRP
to ensure that the SWRP builds on, compliments, and does not conflict with existing priorities and plans.
The responsibilities of regional government agency partners include:
Providing input on the metrics and analysis process used to prioritize projects;
Reviewing components of the SWRP as they are produced by the development team; and
Participating in collaborative meetings.
Table 21. Representatives from regional government agencies
Partners: Funding agencies
The California State Water Resources Control Board (State Water Board) is the primary funding and
oversight agency for the SWRP (Table 22). Their role is to manage the grant with the Tahoe RCD and
provide support and expertise to the SWRP development team. The CTC is the secondary funding and
oversight agency for the SWRP. The CTC is providing additional funds to enhance the State Water Board
funded SWRP by adding Tahoe-basin specific components to the metrics and analysis process. Their role
is to manage the grant with the Tahoe RCD and provide support to the SWRP development team. The
responsibilities of the State Water Board include:
Providing insight into the purpose of the components, and ensuring that the products produced
by the SWRP development team comply with the SWRP Guidelines; and
Participating in collaborative meetings.
ORGANIZATION
TRPA
Lahontan RWQCB
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 37
TAHOE-SIERRA REGION
The responsibilities of the CTC include:
Clearly expressing their needs and desires for the enhanced SWRP specific to the Tahoe-basin;
Coordinating with University scientists;
Ensuring the enhanced SWRP adequately addresses the unique needs of the Tahoe-basin; and
Participating in collaborative meetings.
Table 22. Representatives from funding agencies
Other groups: Universities
Representatives from the University of Nevada, Reno and the University of California, Davis have been
conducting stormwater and other environmental research in the Region for decades (Table 23). The
Universities’ responsibilities include:
Providing input into the metrics and analysis process used to prioritize projects in the Tahoe-basin
when requested; and
Participating in collaborative meetings.
Table 23. Representatives from universities
Other groups: Nongovernmental organizations
The League to Save Lake Tahoe is a local nonprofit that provides a critical link to the community in the
Lake Tahoe-basin as their many education and outreach programs reach locals and visitors alike (Table 24).
They are key stakeholders, but not primary TAC members. Their role is to engage the public in the SWRP
development process when requested. Their primary responsibility is: contacting key members of the
public and requesting participation when appropriate.
Table 24. Representatives from nongovernmental organizations in the Region
ORGANIZATION
League to Save Lake Tahoe
REQUIRED DECISIONS (SWRP GUIDELINES SECTION B.V)
No decisions beyond what is already required for project approval are required by local, state, or federal
regulatory agencies for SWRP implementation. Prior to construction of any public projects identified in the
SWRP, projects are subject to California Environmental Quality Act (CEQA ) review as well as approval by
relevant regulatory agencies and local government. In the Tahoe-basin, environmental projects must be
permitted at the project scale to ensure that they meet local codes as set forth by the TRPA. Project
implementers are responsible for obtaining required approvals from state, federal, and local entities.
OTHER CONSIDERATIONS (SWRP GUIDELINES SECTION B.IV & B.VII)
Identification and discussion of public and community engagement is discussed in SWRP Section F (SWRP
Guidelines Section B.IV). A description of the relationship of the SWRP to other existing planning
documents and programs established by local agencies is included in Section E of this document. (SWRP
Guidelines Section B.VII).
ORGANIZATION
State Water Board
California Tahoe Conservancy
ORGANIZATION
UN Reno, Desert Research Institute
UC Davis, Tahoe Environmental Research Center
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 38
TAHOE-SIERRA REGION
SECTION S C&D METHODS & PROJECT PRIORITIZATION
To achieve the multi-benefit objectives of the SWRP, it is necessary to understand what benefits planned
projects are expected to generate, and how these benefits meet the WQOs within the Region. Before project
benefits can be estimated, metrics must be identified that can quantify those benefits. Once benefits are
quantified, estimates of total project benefit can be determined by aggregating the benefits across several
benefit categories. The aggregate of project benefit estimates indicates progress toward meeting regulatory
requirements, like water quality regulations.
The Region is characterized by open space with dispersed small urban populations. These communities
have varying resources available to plan and implement stormwater projects. Jurisdictions within the
Tahoe-basin (Tahoe jurisdictions) have made significant investments in developing quantitative project
benefit estimates through regulatory requirements to use analysis tools such as the PLRM, GIS application,
and other technical methods. In comparison, jurisdictions outside the Tahoe-basin (non-Tahoe
jurisdictions) do not have the same regulatory requirements to develop quantitative project benefit
estimates. As a result, it is necessary to develop two separate methodologies for identifying projects,
selecting appropriate metrics, and estimating project benefits. The two methods are captured in two
separate sections:
Projects led by jurisdictions in the Tahoe-basin (Guidance for Tahoe jurisdictions)
Projects led by jurisdictions outside the Tahoe-basin (Guidance for non-Tahoe jurisdictions)
Although Tahoe metrics are intended for use by projects within the Tahoe-basin, and non-Tahoe metrics
are intended for use by projects outside the Tahoe-basin, all projects may use any metric, as appropriate.
GUIDANCE FOR TAHOE JURISDICTIONS
Technically complex hydrologic models, like the PLRM and other specific quantitative metrics are used to
characterize and estimate benefits for projects led by jurisdictions inside the Tahoe-basin. This approach
ensures the effort previously expended by these jurisdictions to quantify the expected benefits of their
projects in a technically defensible manner is utilized.
TAHOE IDENTIFICATION OF PROJECTS (SWRP GUIDELINES SECTION C.1)
According to the SWRP Guidelines, SWRPs shall include a metrics-based and integrated evaluation and
analysis of multiple benefits within the watershed Water Code, §10562(b)(2).11 SWRP Guidelines identify
five benefit categories for the metric -based evaluation of multiple project benefits including: water supply,
water quality, flood management, environmental, and community benefits (Figure 15). The SWRP does not
include metrics for the water supply c ategory because water supply is not a priority concern within the
Region Water Code §10562(d)(1). Therefore, prioritizing projects based on water supply benefits would not
represent the needs of the Region. The decision to omit water supply metrics was verified with the
jurisdictions implementing projects who agreed water supply is not a priority and should not be included
in the SWRP. Projects are identified for each jurisdiction to address two or more of these four benefit
categories.
Figure 15. Grey boxes indicate benefit categories included in the SWRP multi-benefit analysis.
11 State Water Resources Control Board. (2015, November 16). Storm Water Resource Plan Guidelines. Retrieved from
http://www.waterboards.ca.gov/water_issues/programs/grants_loans/swgp/docs/draft_guidelines_120315.pdf
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 39
TAHOE-SIERRA REGION
Project identification
Existing lists of stormwater projects within the Region include the IRWMP project lists and the
Environmental Improvement Program (EIP) 5-year project list. The 5-year EIP list is appropriate to use
instead of the full EIP project list because the full project list includes completed projects, while the 5-year
list only includes projects in the planning and implementation stages. The IRWMP project lists may also
include projects that are deferred, or in the post -implementation stage. Projects in these stages were
removed from the list because they were unlikely to request funding, but some jurisdictions chose to keep
projects in the deferred, or post -implementation stage on the list because they believed these projects were
likely to require additional funding. Once the relevant projects from existing lists were identified, the listed
projects were grouped by lead implementer. Each lead implementer then had the opportunity to add or
remove project from the list so it represented their priority projects (Figure 16).
Figure 16. Project identification criteria used to refine existing project lists and produce the SWRP project list. Grey boxes indicate
categories that are included. White boxes with dashed lines indicate categories that are not included.
TAHOE METRICS-BASED ANALYSIS (SWRP GUIDELINES SECTION C.2)
According to the SWRP Guidelines, SWRPs should include an analysis of how projects address the SWRP’s
stormwater management objectives and produce the proposed multiple benefits. Benefits are measured
using metrics. The methodology to estimate project benefits varies based on the specific metric being
measured, and the level of information the project implementer can reasonably provide. The methodology
for selecting project metrics and estimating benefits follows several steps:
1. Selecting project metrics
a. Review available project information to identify project descriptions and quantitativ e
estimates as they are available.
b. Based on available project information, identify relevant metrics for each project (Table
25). Each project must use metrics in at least two benefit categories so the project can be
considered multi-benefit (Appendix F).
c. Check project information against the info sheet to ensure the specifications are met
(Appendix D). If the metric specifications are not met, the project cannot claim the benefit.
This approach ensures benefits are estimated consistently, and the project is likely to
achieve the expected benefit.
2. Estimating project benefits
a. Select the appropriate range for each metric (Table 27). The appropriate range can be
determined based on best professional judgement, knowledge of past projects, or by
developing quantitative estimates.
Selecting project metrics
Tahoe metrics included in the SWRP are selected from the list of EIP performance measures (PM) or
developed by the project team to address benefits not captured by the EIP PMs. PMs selected for inclusion
were those that quantified stormwater benefits in the relevant benefit categories (water quality,
environment, community, and flood management) (Table 25). Additional Tahoe metrics were developed
to quantify benefits in the flood control category, as this category did not have a corresponding EIP PM.
Metrics specifically identifying BMPs for new developments and redevelopments were not included Water
Code §10562(d)(6). This approach was considered overly prescriptive for the Region. Table 25 lists the
Tahoe metrics that will be used to quantify benefits and subsequently rank projects.
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 40
TAHOE-SIERRA REGION
Table 25. Tahoe metrics by benefit category
Each Tahoe metric is described in an info sheet that includes the units, definition, key terms, and
specifications for estimating benefits (Appendix D). Info sheets provide the detailed guidance necessary to
determine whether the project meets the specifications of the metric. If the specifications described in the
info sheet are not met, the project cannot claim the benefit. This approach ensures benefits are estimated
consistently as the project list is updated every two years.
Estimating project benefits
Project benefits are estimated by reviewing the point ranges for each metric (Table 27) and selecting the
range that most closely matches the quantified benefits of the project. If the expected project benefits for a
metric are unknown they can be estimated through best professional judgement, or through more
technically rigorous methods like the PLRM, or GIS analysis. When estimating project benefits, or selecting
a range, conservative estimates should be used. There should be high confidence the project will achieve
the bottom of the range. The top of th e range can be an aspirational level of achievement.
Technical tools to estimate project benefits
Benefits should be estimated using the PLRM, through GIS analysis, or other quantitative tools (Table 26).
A GIS analysis is conducted by running simple queries in mapping software to identify areas treated or
number of facilities improved by a particular project.
Table 26. Methods for estimating Tahoe benefits
METRIC NAME BENEFIT
CATEGORY
ESTIMATION METHOD
PLRM GIS
1 - Fine sediment load reduction Water Quality X
2 - Nitrogen load reduction Water Quality X
3 - Phosphorous load reduction Water Quality X
4 - Parcels with stormwater BMPs Water Quality X
5 - Linear feet of stream channel restored or enhanced Environment X
6 - Acres of habitat restored or enhanced Environment X
7 - Facilities improved or created Community X
8 - Tahoe DAC population served Community X
9 - Community areas enhanced or created Community n/a n/a
10 - Volume of stormwater reduced, stored or infiltrated Flood Mgmt. X
The PLRM is a catchment -scale, continuous simulation model designed to predict average annual pollutant
loads delivered to receiving waters via stormwater. The primary purpose of the PLRM is to assist water
quality planners and project designers in quantitatively evaluating stormwater quality improvement
alternatives for a project that that may involve complex combinations of source controls and stormwater
treatment. The PLRM reports pollutant loads for total suspended solid, fine sediment, and total and
METRIC NAME WATER
QUALITY
ENVIRONMENT COMMUNITY FLOOD
MGMT.
1 - Fine sediment load reduction X
2 - Nitrogen load reduction X
3 - Phosphorous load reduction X
4 - Parcels with stormwater BMPs X
5 - Linear feet of stream channel restored or enhanced X
6 - Acres of habitat restored or enhanced X
7 - Facilities improved or created X
8 - Tahoe DAC population served X
9 - Community areas enhanced or created X
10 - Volume of stormwater reduced, stored or infiltrated X
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 41
TAHOE-SIERRA REGION
dissolved species of phosphorus and nitrogen.12 The PLRM predicts pollutant loads using the following
formula: 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐿𝐿𝑃𝑃𝑃𝑃𝐿𝐿=𝐴𝐴𝐴𝐴𝐴𝐴𝑃𝑃∗𝑃𝑃𝐴𝐴𝐴𝐴𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃∗𝐶𝐶𝑃𝑃𝑃𝑃𝑃𝑃𝐴𝐴𝑃𝑃𝑃𝑃𝑃𝑃𝐶𝐶𝑃𝑃𝑃𝑃𝐶𝐶∗𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐶𝐶𝑃𝑃𝑃𝑃𝑃𝑃𝐴𝐴𝑃𝑃𝑃𝑃𝐴𝐴𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃13
TAHOE GUIDANCE FOR PRIORITIZING PROJECTS (SWRP GUIDELINES SECTION
D.1)
According to SWRP Guidelines, project prioritization should use a metrics-driven approach to quantify
multiple benefits to maximize water quality, flood management, environmental, and community benefits.
Additionally, pursuant to Water Code §10562(b)(2) the SWRP should use “appropriate quantitative methods
for prioritization of projects. (This should be accomplished by using a metrics-based and integrated evaluation and
analysis of multiple benefits to maximize water supply, water quality, flood management, environmental, and other
community benefits within the watershed.)”
To prioritize projects based on multiple benefit categories it is necessary to determine a system for scoring
the metrics used to identify project benefits. The ranges for each point value are determined by reviewing
the actual benefits of implemented projects. Data for completed projects is distributed across the 1 through
5 point values so there is a roughly equal likelihood of currently listed projects receiving each score. The
result is a quantitative range for each 1 through 5 point value for each metric (Table 27). The ranges for
each point value overlap to reflect that benefit estimates are made at early project stages often with low
confidence. Using overlapping ranges provides implementers greater flexibility in selecting a point value
and signals that estimates should not be overly precise, or extremely accurate.
Table 27. Guidance for estimating Tahoe benefits
12 El Dorado County Department of Transportation. (n.d.). PLRS PLRM Comparison (Rep.). CA: El Dorado County.
13 California Tahoe Conservancy. (2011). EL DORADO COUNTY – TAHOE BASIN 2009 POLLUTANT LOAD REDUCTION
STRATEGY Update (Tech.). CA: El Dorado County Department of Transportation.
14 The point ranges for each metric intentionally overlap so that project implementers have flexibility when selecting point values
for their project. This is intended to reflect that benefit estimates are often time preliminary, low-confidence estimates.
METRIC NAME BENEFIT
CATEGORY UNITS POINTS 14
0 1 2 3 4 5
1 - Fine sediment load
reduction Water Quality Pounds/yr 0 1 to 1000 900 to 2400 2200 to 3500 3100 to 4900 4400+
2 - Nitrogen load reduction Water Quality Pounds/yr 0 1 to 5 3 to 9 7 to 13 11 to 20 18+
3 - Phosphorous load reduction Water Quality Pounds/yr 0 1 to 18 16 to 30 27 to 50 45 to 70 65+
4 - Parcels with stormwater
BMPs Water Quality Number 0 1 to 4 3 to 60 50 to 130 100 to 360 300+
5 - Linear feet of stream
channel restored or enhanced Environment Linear ft. 0 1 to 150 100 to 400 350 to 600 550 to 1000 800+
6 - Acres of habitat restored or
enhanced Environment Acres 0 0.1 to 1 0.5 to 2 1.5 to 6 5 to 15 12+
7 - Facilities improved or
created Community Number 0 1 to 2 2 to 3 3 to 4 4 to 5 5+
8 - Tahoe DAC population
served Community No Yes
9 - Community areas enhanced
or created Community No Yes
10 - Volume of stormwater
reduced, stored or infiltrated Flood M gmt. Acre Feet/yr 0 0.25 to 1 0.75 to 1.5 1.25 to 2.25 2 to 3 2.75+
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 42
TAHOE-SIERRA REGION
To determine the total score for each project, the points for each metric within the same benefit category
are averaged. Points are then summed across benefit categories to determine the total project score. The
result is the total project score used to rank each project (Figure 17).
Figure 17. Project scoring method. Light grey boxes represent metric scores within each benefit category (dark grey boxes). Light
blue boxes show that metrics within each benefit category are averaged and then summed to determine the total project score
(dark blue box).
A ranked project list is developed for each jurisdiction (Appendix E). Projects are only ranked against
other projects by the same jurisdiction.
TAHOE WATER QUALITY ANALYSIS (SWRP GUIDELINES SECTION C.2.a )
The multiple benefits of listed projects collectively contribute to meeting regulatory requirements within
the Region, such as TMDLs, NPDES permits, and WDRs. The Lake Tahoe Municipal NPDES Phase 1 permit
(Municipal permit) regulates stormwater and urban runoff discharges from El Dorado County, Placer
County, and the City of South Lake Tahoe within the Lake Tahoe HU (Order No. R6T-2017-0010)15. The
NPDES permit identifies baseline loads and allowable load targets for FSPs, TP, and TN (Table 28).
Table 28. Municipal permit water quality requirements
POLLUTANT EL DORADO COUNTY PLACER COUNTY CITY OF SOUTH LAKE TAHOE
FSP
(particles/yr)
Baseline 1.63 x 1019 2.64 x 1019 2.44 x 1019
Allowable Load 1.29 x 1019 2.09 x 1019 1.93 x 1019
TP (lbs/yr) Baseline 1,170 2,280 2,063
Allowable Load 1,006 1,961 1,774
TN (lbs/yr) Baseline 4,170 8,860 8,185
Allowable Load 3,586 8,185 7,039
The Municipal permit requires jurisdictions to develop Pollutant Load Reduction Plans (PLRP) which
provide an analysis of how each jurisdiction plans to achieve the allowable load. PLRPs are an important
planning tool for documenting load reductions achieved by completed projects and estimating how future
proj ects make progress toward the allowable load. PLRPs developed in 2013 identified the load reduction
achieved by completed projects and estimate the load reduction from then current projects. 2018 updates
of the PLRPs identify the load reduction achieved by projects implemented since 2013 and indicate progress
toward the allowable load target. Additionally, the 2018 updates of the PLRPs include estimates for current
projects, such as those on the SWRP project lists. Listed projects for each of the three jurisdictions regulated
under the Municipal permit achieve the water quality requirements of the permit by reducing pollutants
from baseline quantities to allowable loads. The estimated reduction of each listed project is documented
in the implementing jurisdiction’s PLRP.
15 Renewed WDR and NPDES permit for stormwater/ urban runoff discharges from El Dorado County, Placer County, and the City
of South Lake Tahoe within the Lake Tahoe HU, Order No. R6T-2017-0010 NPDES No. CAG616001 California Regional Water
Quality Control Board Lahontan Region (2017).
http://www.waterboards.ca.gov/lahontan/board_decisions/adopted_orders/2017/docs/r6t2017_0010_lake_tahoe_npdes.pdf
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 43
TAHOE-SIERRA REGION
TAHOE MULTIPLE BENEFITS (SWRP GUIDELINES SECTION D.2)
The aggregate benefits of implemented SWRP projects are tracked through the SWRP tracker using metrics.
Because each metric has a stated definition and values, it is possible to aggregate the benefits associated
with each metric across projects. Each project reports a metric score for each metric used. Each metric score
has a range shown in the metric table (Table 27). To aggregate quantitative metrics, the mid-point of each
score range is used. As a result, the total expected benefit across multiple projects can be determined.
As a result, information is available about the water quality, environmental, community, and flood
management benefits to the region from planned and implemented projects. This information is useful for
understanding progress toward regulatory targets and community goals. Additionally, this information is
useful when determining whether to update the metric list during the adaptive management process.
Each project or program implemented in accordance with the SWRP should address at least two “Main
Benefits” as listed in Table 4 of the Guidelines and as many “Additional Benefits” as feasible (also listed in
Table 4 of the guidelines. The SWRP uses benefit categories to represent “Main Benefits” and multiple
metrics within each benefit category to provide “Additional Benefits”. The number of benefit categories
achieved by each project is tracked in (Appendix H)
TAHOE DATA MANAGEMENT (SWRP GUIDELINES SECTION C.3)
According to SWRP Guidelines, the SWRP should describe data collection and management including
mechanisms by which data will be managed and stored, how data will be accessed by stakeholders and th e
public, and the frequency with which data will be updated.
Data location
Data for all projects on the SWRP list and the list itself are publicly available on the Tahoe RCD website
(http://tahoercd.org/stormwater-resources -plan/). In the future, this data will be incorporate with the
existing EIP project tracker on the LT Info portal (https://eip.laketahoeinfo.org/)
Data available
Project data are publicly available for download. Project data are provided to the Tahoe RCD by
the lead implementer of the project when the project is added to that jurisdiction’s SWRP list.
Project data includes quantitative metrics that allow the project to be scored and ranked.
The SWRP project list is in the form of an excel document publicly available for download. Data
for each project includes the project name and score by applicable metric, and rank. Projects are
only ranked against other projects led by the same jurisdiction.
Data management
Implementing jurisdictions can submit project data to Tahoe RCD at any time. On an annual basis, Tahoe
RCD scores and ranks the project in an Excel sheet and adds it to the jurisdiction’s SWRP list. The Excel
sheet used to score and rank projects is updated by Tahoe RCD so there is a record of the process and result.
The project data and the resulting project list will be made publicly available on the Tahoe RCD website.
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 44
TAHOE-SIERRA REGION
GUIDANCE FOR NON-TAHOE JURISDICTIONS
Non-Tahoe metrics are used to characterize and estimate benefits for projects led by jurisdictions outside
the Tahoe-basin. Non -Tahoe jurisdictions are often more focused on the flood management, community,
and environmental benefits of stormwater projects than the water quality benefits. The list of metrics
reflects these priorities by including several metrics to address each of these benefit categories.
NON-TAHOE IDENTIFICATION OF PROJECTS (SWRP GUIDELINES SECTION C.1)
SWRP Guidelines identify five benefit categories for the metric -based evaluation of multiple project
benefits including: water supply, water quality, flood management, environmental, and community
benefits Water Code §10562(b)(2).16 The SWRP does not include metrics for the water supply category
because water supply is not a priority concern within the Region. Therefore, prioritizing projects based on
water supply benefits would not represent the needs of the Region. The decision to omit water supply
metrics was verified with the jurisdictions implementing projects who agreed water supply is not a priority
and should not be included in the SWRP. The SWRP considers water quality, flood management,
environmental, and community benefits from implemented projects (Figure 18). Projects are identified for
each jurisdiction to address two or more of these four benefit categories.
Figure 18. Benefit categories included in the SWRP multi-benefit analysis.
Project identification
The existing IRWMP project list may include projects that are completed, deferred, or in the post-
implementation stage. Projects in these stages were removed from the list because they were unlikely to
request funding, but some jurisdictions chose to keep projects in the deferred, or post -implementation stage
on the list if they believed these projects were likely to require additional funding.
Once the relevant projects from the IRWMP list were identified, the listed projects were grouped by lead
implementer. Each lead implementer then h ad the opportunity to add or remove projects from the list so
it represented their priority projects (Figure 19).
Figure 19. Project identification criteria used to refine existing project lists and produce the SWRP project list. Grey boxes indicated
criteria that are included. White boxes with dashed lines indicate criteria that are not included.
NON-TAHOE METRICS-BA SED ANALYSIS (SWRP GUIDELINES SECTION C.2)
According to this SWRP Guidelines, SWRPs should include an analysis demonstrating how projects
address the SWRP’s stormwater management objectives and produce multiple benefits listed in Table 29.
Benefits are measured using the previously identified non-Tahoe metrics. The methodology to estimate
project benefits varies based on the specific metric selected, and the level of information the project
implementer can reasonably provide. The methodology for selecting project metrics and estimating
benefits follows several steps:
16 State Water Resources Control Board. (2015, November 16). Storm Water Resource Plan Guidelines. Retrieved from
http://www.waterboards.ca.gov/water_issues/programs/grants_loans/swgp/docs/draft_guidelines_120315.pdf
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 45
TAHOE-SIERRA REGION
1. Selecting project metrics
a. Review available project information to identify project descriptions and quantitativ e
estimates as they are available.
b. Based on project information available, identify relevant metrics for each project (Table
29). Each project must use metrics in at least two benefit categories so the project is multi-
benefit (Appendix I).
c. Check project information against the info sheet to ensure the specifications are met
(Appendix G). If the metric specifications are not met, the project cannot claim the benefit.
This approach ensures benefits are estimated consistently, and the project is likely to
achieve the expected benefit.
2. Estimating project benefits
a. Select the appropriate point value for each metric (Table 30) based on the criteria or
quantitative range of values. The point value can be determined based on best professional
judgement, knowledge of past projects, or by developing quantitative estimates.
Selecting project metrics
Non-Tahoe metrics included in the SWRP are developed by the project team through conversations with
the non-Tahoe jurisdictions. Metrics specifically identifying BMPs for new developments and
redevelopments were not included Water Code §10562(d)(6). As a result, metrics are developed that
represent the priorities of these jurisdictions and address the four benefit categories (water quality,
environment, community, and flood management) (Table 29).
Table 29. Non-Tahoe metrics by benefit category
Each non-Tahoe metric is described through an info sheet that includes the units, definition, key terms, and
specifications for estimating benefits (Appendix G). Info sheets provide the guidance necessary to
determine whether the project meets the specifications of the metric. For the estimated project benefits to
be valid, the attributes of the project which result in that benefit must be checked against the specifications
in the info sheet to verify the specifications are met. If the specifications in the info sheet are not met, the
project cannot claim the benefit. This approach ensures benefits are estimated consistently, and the project
is likely to achieve the expected benefit.
METRIC NAME WATER
QUALITY ENVIRONMENT COMMUNITY FLOOD
MGMT.
11 - Drains to TMDL waterbody X
12 - Provides source control for stormwater pollutant X
13 - Pollutant load reduction X
14 - Volume of stormwater treated X
15 - Total suspended solid load reduction X
16 - Parcels with stormwater BMPs X
17 - Project restores, enhances, or creates habitat X
18 - Stream channel restored, enhanced, or created X
19 - Non-Tahoe DAC population served X
20 - Employment opportunity created X
21 - Enhance or create community areas X
22 - Project improves property values X
23 - Proximity to flood-prone channel X
24 - Runoff reduced through storage or infiltration X
25 - Impervious area reduced (%) X
26 - Natural hydrology/ hydrograph reestablished X
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 46
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Estimating project benefits
Project benefits are estimated by reviewing the point descriptions for each metric (Table 30) and selecting
the description, or range that most closely matches the expected benefits of the project. If the expected
benefit for a metric is unknown it can be estimated through best professional judgement or GIS analysis.
When estimating a range, there should be high confidence the project will achieve the bottom of the range.
The top of the range can be aspirational, but realistic for the project to achieve.
NON-TAHOE GUIDANCE FOR PRIORITIZING PROJECTS (SWRP GUIDELINES
SECTION D.1)
According to SWRP Guidelines, project prioritization should use a metrics-driven approach to quantify
multiple benefits to maximize water quality, flood management, environmental, and community benefits.
Additionally, pursuant to Water Code §10562(b)(2) the SWRP should use “appropriate quantitative methods
for prioritization of projects. (This should be accomplished by using a metrics-based and integrated evaluation and
analysis of multiple benefits to maximize water supply, water quality, flood management, environmental, and other
community benefits within the watershed.)”
To prioritize projects based on multiple benefit categories it is necessary to determine a system for scoring
the metrics used to identify project benefits. The ranges for each point value are determined through
conversations with jurisdictions and best professional judgement (Table 30). The ranges for each point
value overlap to reflect that benefit estimates are made at early project stages often with low confidence.
Using overlapping ranges provides implementers greater flexibility in selecting a point value and signals
that estimates should not be overly precise, or extremely accurate.
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 47
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Table 30. Guidance for estimating non-Tahoe benefits
METRIC NAME BENEFIT
CATEGORY
POINTS 17
0 1 2 3 4 5
11 - Drains to TMDL waterbody Water Quality No Yes
12 - Provides source control for
stormwater pollutant Water Quality No Yes
13 - Pollutant load reduction Water Quality No All other
pollutants 303(d) listed
pollutant Approved TMDL
pollutant
14 - Volume of stormwater treated Water Quality 0 0.1-0.8 Af/yr 0.7 – 1.2 Af/yr 1.1 – 1.6 Af/yr 1.5 - 2 Af/yr >1.9 Af/yr
15 - Total suspended solid load
reduction Water Quality <1,000 lb/yr 750-6,000 lb/yr 5,000-12,000 lb/yr 10,000-30,000 lb/yr 25,000-50,000 lb/yr 45,000+ lb/yr
16 - Parcels with stormwater BMPs Water Quality 0 1 to 4 3 to 60 50 to 130 100 to 360 300+
17 - Project restores, enhances, or
creates habitat Environment No Yes Listed species Endangered
species
18 - Stream channel restored,
enhanced, or created Environment No Yes Listed species Endangered
species
19 - Non-Tahoe DAC population
served Community No Yes
20 - Employment opportunity
created Community No Short-term Long-term
21 - Enhance or create community
areas Community No Yes
22 - Project improves property
values Community No Yes
23 - Proximity to flood-prone
channel Flood Mgmt. not in subbasin >1 miles 0.75mile – 0.25mile 0.3mile – 0.1mile 0.15mile – 75yds <100yds
24 - Runoff reduced throug h
storage or infiltration Flood Mgmt. No
Yes, but
flooding is not a
problem locally
Yes, minor
flooding locally Yes, major
flooding locally
25 - Impervious area reduced (%) Flood Mgmt. <30% 25% - 45% 40% - 60% 55% - 75% 70% - 90% 85% – 100%
26 - Natural hydrology/
hydrograph reestablished Flood Mgmt. No Yes
17 The ranges for each metric intentionally overlap so that project implementers have flexibility when selecting point values for their project. This is intended to reflect that benefit estimates
are preliminary and likely to adjust as projects develop.
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To determine the total score for each project the points for each metric within the same benefit category are
averaged. Points are then summed across benefit categories to determine the total p roject score. The result
is the total project score used to rank each project (Figure 20).
Figure 20. Project scoring method. Light grey boxes represent metric scores within each benefit category (dark grey boxes). Light
blue boxes show that metrics within each benefit category are averaged and then summed to determine the total project score
(dark blue box).
A ranked project list is developed for each jurisdiction (Appendix H). Projects are only ranked against
other projects by the same jurisdiction.
NON-TAHOE WATER QUALITY ANALYSIS (SWRP GUIDELINES SECTION C.2.a )
The multiple benefits of listed projects collectively contribute to meeting regulatory requirements within
the Region, such as TMDLs, NPDES permits, and WDRs. Outside the Lake Tahoe HU, the SWRCB NPDES
permit (Phase II permit) sets WDRs for stormwater discharges from Municipal Separate Storm Sewer
Systems (MS4s) including the Town of Truckee (Table 31) and the area of Placer County outside the Tahoe-
basin but east of the Sierra Crest (Middle Truckee River Drainage). (Order No. 2013-0001-DWQ)18 The
Town of Truckee and Placer County are the only agencies within the SWRP Region that are regulated by
the Phase II permit.
TMDLs can also assign additional requirements to NPDES permittees through wasteload allocations. The
Sediment TMDL for the Middle Truckee River was reviewed to identify wasteload allocations applicable
to the Town of Truckee. Compliance with the TMDL requires implementation of a Stormwater
Management Program (SWMP), monitoring and reporting of road sediment applied and removed, and
adoption and enforcement of ordinances and policies to control sources of pollution in stormwater runoff.
The Town of Truckee will continue to implement these actions SWRP and thus implementation of the
SWRP will be consistent with the applicable NPDES and WDR's outside of the Tahoe-basin.
A wasteload allocation was assigned to urban runoff in the Town of Truckee on a subwatershed basis
(Section 7 of the TMDL). Wasteload allocations for sediment in tons/year were assigned on the assumption
that BMPs would be maintained with a removal efficiency of 50% (for sediment). To ensure the SWRP is
consistent with the WDR (i.e., Phase II TMDL permit ), projects should demonstrate that BMPs, low impact
development or other practices are installed and maintained with at least a 50% sediment removal
efficiency.
Table 31. Phase II permit water quality requirements
POLLUTANT TOWN OF TRUCKEE
Sediment
SWMP implementation
Monitoring and reporting of road sediment applied and removed
Adoption and enforcement of ordinances to control pollution in runoff
BMPs maintained with 50% removal efficiency
18 WDRs for stormwater discharges from small municipal separate storm sewer systems (MS4s) (General permit), Water Quality
Order No. 2013-0001 General permit No. CAS000004 California Regional Water Quality Control Board Lahontan Region (2013).
http://www.swrcb.ca.gov/water_issues/programs/stormwater/docs/phsii2012_5th/order_final.pdf
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NON-TAHOE MULTIPLE BENEFITS (SWRP GUIDELINES SECTION D.2)
The aggregate benefits of implemented SWRP projects are tracked through the SWRP tracker using metrics.
Because each metric has a stated definition and values, it is possible to aggregate the benefits associated
with each metric across projects. Each project reports a metric score for each metric used. Each metric score
has a range shown in the metric table (Table 27). To aggregate quantitative metrics, the mid-point of each
score range is used. As a result, the total expected benefit across multiple projects can be determined.
As a result, information is available about the water quality, environmental, community, and flood
management benefits to the region from planned and implemented projects. This information is useful for
understanding progress toward regulatory targets and community goals. Additionally, this information is
useful when determining whether to update the metric list during the adaptive management process.
Each project or program implemented in accordance with the SWRP should address at least two “Main
Benefits” as listed in Table 4 of the Guidelines and as many “Additional Benefits” as feasible (also listed in
Table 4 of the guidelines. The SWRP uses benefit categories to represent “Main Benefits” and multiple
metrics within each benefit category to provide “Additional Benefits”. The number of benefit categories
achieved by each project is tracked in (Appendix H)
NON-TAHOE DATA MANAGEMENT (SWRP GUIDELINES SECTION C.3)
Data location
Data for all projects on the SWRP list and the list itself are publicly available on the Tahoe RCD website
(http://tahoercd.org/stormwater-resources-plan/).
Data available
Project data are publicly available for download. Project data are provided to the Tahoe RCD by
the lead implementer of the project when the project is added to that jurisdiction’s SWRP list.
Project data includes quantitative metrics that allow the project to be scored and ranked.
The SWRP project list is in the form of an excel document publicly available for download. Data
for each project includes the project name and score by applicable metric, and rank. Projects are
only ranked against other projects led by the same jurisdiction.
Data management
Implementing jurisdictions can submit project data to Tahoe RCD at any time. On an annual basis, Tahoe
RCD scores and ranks the project in an Excel sheet and adds it to the jurisdiction’s SWRP list. The Excel
sheet used to score and rank projects is updated by Tahoe RCD so there is a record of the process and
result. The project data and the resulting project list will be made publicly available on the Tahoe RCD
website.
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SECTION E. PLAN IMPLEMENTATION STRATEGY AN D SCHEDULING
OF PROJECTS
Procedures for implementation of the SWRP ensure clear roles and procedures to maintain the project list
over time so that implementers remain eligible for funding. Additionally, these procedures demonstrate
how implemented projects meet regulatory requirements and benefit communities. Pollutant load
reduction targets within the Tahoe-basin are adjusted every 5 years when a new NPDES Phase I municipal
permit is adopted. Projects implemented through the SWRP make progress toward meeting the regulatory
targets set by the municipal permit. Outside the Tahoe -basin jurisdictions implement projects to achieve
the Phase II permit, TMDL requirements, or benefit the community through ecosystem restoration and
flood management. The intent of SWRP implementation and adaptive management is not to complete
projects lists, but to achieve programmatic targets and make meaningful differences to communities.
RESOURCES FOR PLAN IMPLEMENTATION (SWRP GUIDELINES SECTION E.1)
According to the Water Code, the SWRP should identify the resources that the participating entities are
committing for implementation of the Plan Water Code §10562(d)(8). Tahoe RCD will lead and pursue funding
for activities to implement and adaptively manage the SWRP. Partnerships with the jurisdictions
responsible for permit compliance and/or applying for bond funding may be pursued to secure funding.
Although there is currently not a dedicated funding source for implementation and management of the
SWRP, Tahoe RCD is committed to pursuing the necessary funding.
Funding is required to implement, as well as operate and maintain projects. In most cases, it is the
responsibility of the project proponents to ensure that construction and operations and maintenance
funding needs are met for each project. Jurisdictions are expected to rely primarily on State or Federal
grants and loans for construction, and local funding for operation and maintenance of projects. Although
funding for stormwater programs is limited there are some options which implementing agencies can
consider to funding SWRP implementation including: operating funds, water enterprise funds, special
taxes, assessments, private loans, and local bonds. Recent passage of SB231 does clarify that stormwater
management fees are excluded from Proposition 218 restrictions. This clarification means that new
stormwater fees can be passed by a 50% majority of voters rather than 66%; however, even the lowered
barrier presents very a substantial hurdle and is not considered an easy path to new funding for stormwater
projects. More specific estimates for how project costs will be financed are available for projects on the
SWRP list which are also on the IRWMP list.19
Jurisdictions have a general understanding of the schedule for development and implementation of their
projects based on initial project planning and best professional judgement. Additionally, jurisdictions in
the Tahoe-basin are currently implementing fewer projects than was typical in previous years. Therefore,
Implementers have the capacity and information necessary to plan and implement their projects as soon as
funding becomes available. The timelines and funding requirements for projects will become more accurate
and precise, as planning progresses. Information available on initial project costs including the estimated
funding need, portion of funding secured, and remaining unfunded need is shown in Appendix J.
IMPLEMENTATION PROGRAM (SWRP GUIDELINES SECTION E.2)
According to the Water Code, an entity developing a SWRP shall identify in the plan: projects and programs
to ensure the effective implementation of the SWRP…to achieve multiple benefits. These projects and programs shall
include the development of appropriate decision support tools and the data necessary to use the decision support tools.
19 Tahoe-Sierra IRWMP (Rep.). (2014, July). Table 8-2. Retrieved http://tahoesierrairwm.com/
STORMWATER RESOURCE PLAN: TAHOE-SIERRA REGION PAGE 51
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The Plan shall identify…ordinances or other mechanisms necessary to ensure the effective implementation of the
SWRP Water Code §10562(d)(8)&(9).
Entities responsible for implementation
Development, implementation and adaptive management of the SWRP over time is the responsibility of
several groups: the Tahoe RCD, project implementers, the TAC (defined in Section B) and the Public
(defined in Section F). The responsibilities of each entity are summarized in Figure 21. The members of each
entity and the relationships between them are described in more detail in the following sections.
Figure 21. Roles (colored boxes) and responsibilities (bullet points) for SWRP development, implementation and adaptive
management.
Existing programs supporting implementation
Within the Tahoe-basin, the Lake Clarity Crediting Program (Crediting Program) motivates effective
actions to improve Lake Tahoe clarity by establishing a load reduction accounting system that connects on-
the-ground actions to incremental progress towards milestones set by the Lake Tahoe TMDL. The Crediting
Program quantifies and tracks pollutant controls implemented to reduce the load of FSPs, nitrogen and
phosphorus from urban stormwater.20 Projects on the SWRP list are designed and implemented within the
Tahoe-basin until the municipal stormwater permit’s “credit targets” are achieved. The current list of
projects achieves the current milestone, but further projects will be needed to achieve future milestones
and maintain compliance. The Crediting Program is made possible through the use of several decision
support tools including the PLRM, and the Lake Tahoe Info Stormwater Tools. The PLRM is described in
Section s C. The Lake Tahoe Info Stormwater Tools are used to track Lake Tahoe TMDL implementation
progress in urbanized portions of the watershed. No analogous programs exist outside of the Tahoe-basin.
Strategy for obtaining necessary permits
The jurisdiction leading each project on the SWRP list is responsible for securing funding and obtaining
the permits necessary for implementation. The SWRP and the Tahoe-Sierra IRWMP do not conflict with
any legal obligation of any project proposer, “including those under contracts, licenses, permits, regulations
and statues.” In the Tahoe-basin, environmental projects must be permitted at the project scale to ensure
that they meet regional codes as set by the TRPA. Outside of the Tahoe-basin project work within or near
a Water of the United States or Water of the State of California requires approval from regulatory agencies
on a project scale. Additionally, projects may require additional permits including, but not limited to the
Lahontan General Construction permit, CTC License Agreements, USFS Special Use Permits, US Army
Corps of Engineers Section 404 permits, Lahontan 401 Water Quality certification, CDFW incidental take
permit, Caltrans encroachment permits.
20 Lahontan Water Quality Control Board and Nevada Division of Environmental Protection. 2015. Lake Clarity Crediting Program
Handbook: for Lake Tahoe TMDL Implementation v2.0. Prepared by Environmental Incentives, LLC. South Lake Tahoe, CA.
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Incorporation of the SWRP into the Tahoe-Sierra IRWMP
According to the Water Code, the SWRP “will be submitted, upon development to the applicable IRWM group
for incorporation into the IRWMP” Water Code §10562(b)(7). Upon acceptance of the SWRP by the State
Water Board, a link to the SWRP materials 21 is posted on the IRWM website. The link enables access to the
SWRP document and project list for each jurisdiction. SWRP project lists are updated every two years and
posted on the same website. As a result, the link on the IRWM website remains current as the SWRP project
lists are updated over time.
Community participation strategy for SWRP implementation
Section B of the SWRP describes the stakeholders engaged during SWRP development including:
implementers, partners and other parties. (SWRP stakeholders) These three groups are members of
communities within the Region that implement, or benefit from stormwater projects. Section F describes
public participation during the development and implementation of the SWRP including public
engagement through a public workshop, personal communications, and a webpage where materials
relevant to SWRP development are accessible.
Additionally, community participation during implementation of SWRP projects can use the existing
procedures identified by the IRWMP. The IRWMP ensures that the public and interested stakeholders are
involved in plan implementation through multiple avenues of communication and engagement among the
IRWM participants.22
ADAPTIVE MANAGEMENT (SWRP GUIDELINES SECTION E .3) & PERFORMANCE
MEASURES (SWRP GUIDELINES SECTION E.4)
According to SWRP Guidelines, the SWRP should be structured as a living document and implemented as
an ongoing, adaptive program to monitor progress toward regulatory objectives and benefit goals. The
SWRP should also explain how the identified projects and programs achieve the multiple-benefit goals and
regulatory requirements of the Region. Additionally, the SWRP should “identify the development of
appropriate decision support tools and the data necessary to use the decision support tools” Water Code §10562(d)(8)
to support the adaptive management process. The adaptive management process does not replace required
regulatory reporting by specific agencies within the Region.
Purpose of adaptive management
To ensure consistency and transparency over time, changes
to the SWRP follow an adaptive management process based
on four components (Figure 22). For example, the SWRP
project data and subsequent project list can be updated
regularly, and if necessary, the Tahoe and non-Tahoe metric
lists can be revised. New projects can be added, scored, and prioritized at any time by accessing the SWRP
Project Tracker excel spreadsheet on the Tahoe RCD website. It is anticipated that an online portal will be
developed through the TRPA’s LT Info platform to replace the excel spreadsheet for in -basin jurisdictions.
The metric lists can be updated every two years to ensure they remain useful to the project implementers
and support the multi-benefit goals of the Region. Updating progress toward regulatory requirements and
multi-benefit goals every two years ensures listed projects are targeted to the needs of the Region.
21 The SWRP Tracker is an Excel spreadsheet containing the products of the adaptive management process. The SWRP Tracker is
described in detail in the Error! Reference source not found. se ction.
22 Tahoe-Sierra IIRWMP (Rep.). (2014, July). Section 8.2.3. Retrieved http://tahoesierrairwm.com/
The adaptive management process
outlines a framework for updating
the SWRP project list over time.
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Figure 22. Four components of the adaptive management process (blue polygons) and the SWRP Tracker products (icons in circles).
Adaptive management products
The findings of each component of the process is captured through the SWRP Tracker (Appendix K) for
non-Tahoe jurisdictions, and the EIP project tracker on the LT Info platform for Tahoe jurisdictions. Each
component captures specific information to inform the adaptive management process (Figure 23):
Project list: The current ranked project list for each jurisdiction. The Excel sheet SWRP Tracker
for non-Tahoe jurisdictions and the online EIP project tracker for Tahoe jurisdictions.
Project data: Data for each SWRP project including the lead implementer, project status,
expected benefits, and metrics.
Benefit tracking: Comparison of regulatory targets with estimated benefits of implemented
projects and aggregates benefits of projects by category. Targets may have been updated due to
new research.
Metrics: Tahoe and non-Tahoe metric lists and point ranges.
Recommendation email: An email sent from Tahoe RCD to the TAC with proposed changes
to the SWRP. Potential changes include new projects, adjustments to the metric list and
administrative changes made to the SWRP. A copy of the email is uploaded to the SWRP project
website.
TAC & Public meeting: A meeting led by Tahoe RCD with the TAC and public in attendance.
The purpose of the meeting is to review recommended changes. After the meeting a meeting
report is written by Tahoe RCD and uploaded to the SWRP project website. The report
summarizes the decisions made at the meeting about updates to the SWRP metrics.
Adaptive management procedure
Each component of the adaptive management process follows several steps led by the entities responsible
for implementation identified above (Tahoe RCD, Project Implementers, TAC & Public).
Figure 23. The first component of the adaptive management process involves reporting performance in a quantitative way.
Tracking & Reporting Performance is the process for consistently tracking and reporting implementation
of SWRP projects through the following steps (Figure 24). This ensures clear communication between
implementers, Tahoe RCD, the public, and the TAC. Tracking and reporting is a necessary precursor to
determining progress toward regulatory requirements and multi-benefit goals.
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1. Report initial benefit estimates: project implementers must provide benefit estimates using the
metrics listed in the SWRP for any projects they want added to their project list. The benefit
estimates for each project are reported to Tahoe RCD and recorded in the SWRP Tracker or on LT
Info.
2. Implement projects: projects on the SWRP list are developed and delivered by project
implemen ters such as municipalities, counties and others.
3. Report benefits for completed projects: every two years project implementers report benefits to
Tahoe RCD for completed projects on the SWRP list using the same method as estimating benefits
for planned projects. Reporting estimated benefits before and after project implementation
indicates to the implementer the accuracy of their initial estimates which leads to better future
estimates. Reporting benefit estimates supports additional long-term funding.
Figure 24. The second component of the adaptive management process is synthesizing several types of information into a set of
management-related findings.
Synthesizing Findings is the process of integrating disparate information so that decisions are well-
informed, the SWRP remains useful to implementers, and relevant to the Region’s needs (Figure 25).
Available information is synthesized through the following steps:
1. Determine progress toward regulatory targets and multi-benefit goals: Jurisdictions within
the Tahoe -basin are required to track progress toward their municipal permit water quality targets
through the development of PLRPs. Progress toward PLRP targets are updated every two years
based on estimated benefits reported by project implements to Tahoe RCD. Progress toward
regulatory targets and multi-benefit goals are captured in the SWRP Tracker or LT Info . If the PLRP
has been updated more recently than the SWRP it will likely have the more accurate and most up -
to-date estimates of progress toward regulatory targets.
2. Review metric list and ranges: Using th e SWRP Tracker Tahoe RCD reviews the metrics used by
project implementers to determine which metrics should be removed or added.
Figure 25. The third component of the adaptive management process is recommending adjustments in project lists, metrics and
administrative processes to the TAC and public.
Recommending Adjustments is the process for developing recommendations and r eviewing them with
the TAC and the Public through the following steps (Figure 26):
1. Suggest updates to metric list: Tahoe RCD recommends metrics to be removed from or added
to the list. Metric point ranges may also be modified to ensure they continue to differentiate
projects. These recommendations are sent to the TAC in an email with brief justifications for the
proposed changes using the provided email template.
2. Review and comment on proposed changes: A meeting is held where TAC m embers and the
Public have the opportunity to review and comment on changes proposed to the metric list. Tahoe
RCD considers input from TAC members before finalizing changes to the SWRP. Decisions made
at the meeting are captured in the Meeting Report.
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Figure 26. The fourth component of the adaptive management process is to implement changes to the SWRP.
Adopting & Implementing Program Adjustments is the process for adopting and implementing program
adjustments through the following steps:
1. Update metric list: Tahoe RCD updates the metric list . The updated information is used to add
new projects to the SWRP project lists.
2. Report project status: every two years project implementers are responsible for reporting the
status of their currently listed projects to Tahoe RCD. Additionally, project implementers are
responsible for identifying new projects to add to their SWRP project list, and estimating funding
needs (project cost, secured funding amount, remaining unmet need). This information is captured
in th e SWRP Tracker. It should be noted that funding estimates are also provided in the IRWM and
on LT Info. If these sources have been updated more recently than the SWRP they are likely be
more accurate.
3. Update SWRP project list: New projects can be added or removed by implementing jurisdictions
at any time via the SWRP Project Tracker hosted on the Tahoe RCD website for out -of-basin
jurisdictions or through an anticipated portal on TRPA’s LT Info website for in -basin jurisdictions .
Adding or removing a project in the SWRP Project Tracker on the Tahoe RCD website will
necessitate manual revision of the prioritized project lists for out -of-basin jurisdictions by Tahoe
RCD staff. Adding or removing a project through the anticipated LT In fo portal will automatically
update the prioritized project lists for in -basin jurisdictions.
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SECTION F. EDUCATION, OUTREACH, AND PUBLIC PARTICIPATION
Public participation during the development and implementation of the SWRP attempted to maximize the
community benefits of watershed scale stormwater management. Opportunities for public education and
engagement during development of the SWRP included a public forum, open TAC meetings, personal
communications, social media posts and shares, and a webpage where materials relevant to SWRP
development were accessible to the public , Water Code §10562(b)(4).
PUBLIC EDUCATION & PARTICIPATION (SWRP GUIDELINES SECTION F.I & F.II)
Implementation of the SWRP did not require consideration of any major technical or po licy issues, yet
multiple opportunities for public engagement during development of the SWRP were pursued. Two public
forums were held, one inside the basin on the south shore of Lake Tahoe and one outside of the basin in
the Town of Truckee in December 2017 to inform the public about the purpose of the SWRP and to educate
them about the multiple benefits stormwater projects can have to things they care about: water quality,
habitat enhancement, recreational opportunities, and the economy. Additionally, all five TAC meetings
were open to the general public. Forum and meeting locations, dates, and times were publicized with a 30-
day notice via the outreach and communication methods and tools outlined below and were specifically
targeted to the audiences named below. Meeting reports for public and TAC meetings, as well as draft
SWRP products were posted for public comment on the Tahoe RCD website and shared via Tahoe RCD’s
Facebook page.
AFFECTED COMMUNITIES (SWRP GUIDELINES SECTION F.III)
CEQA allows for public engagement in major decisions and processes related to environmental projects
that will be implemented. Additionally, each jurisdiction follows their own protocols and procedures for
encouraging public comment during project design and implementation such as open Board of Supervisors
or City Council meetings and forums dedicated to hearing public comment on sensitive or contentious
projects. The method of outreach to affected populations will be the responsibility of each jurisdiction
implementing a proj ect.
SPECIFIC AUDIENCES (SWRP GUIDELINES SECTION F.IV & F.V)
Specific audiences for whom the SWRP or stormwater projects in general might be relevant include
developers, locally regulated commercial and industrial enterprises, school districts, and disadvantaged
communities. A brief description of each is provided below. Efforts were made to contact representatives
from each of these audiences to encourage them to attend one of the public forums held in December 2017
and review the draft SWRP. Leaders of the specific audiences were contacted directly via phone and/or
email for participation in the public forum and SWRP draft review.
Ratepayers are not relevant within the Region because there is no fee structure in place to pay for
stormwater. The primary nongovernmental/nonprofit organization involved in stormwater management
in the Region is the League to Save Lake Tahoe (Section B).
Developers
Developers or construction companies are often contracted to construct portions of the stormwater projects
designed by the implementing jurisdictions.
Locally regulated commercial and industrial enterprises
Local enterprises are currently enrolled in the statewide General Stormwater Industrial Permit which
regulates industrial stormwater discharges and authorized non-stormwater discharges from industrial
facilities in California. Though they are not required to implement stormwater projects, they are subject to
effluent limitation guidelines and must develop Stormwater Pollution Prevention Plans.
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School districts
Beginning in 2019, school districts in the state of California will be added to the statewide Phase II
Municipal Stormwater Program General Permit. Inclusion in this permit requires school districts to control
pollutants originating from their campuses. Thus, school districts in the Region will eventually need to
implement stormwater projects.
Disadvantaged and climate vulnerable communities
The Washoe Tribe is the primary disadvantaged community in the Region. Their population is largely
dispersed within the Tahoe-basin and surrounding areas, and as such they are not concentrated in areas of
frequent or excessive flooding, considerable habitat degradation, economic adversity, or poor water
quality. However, they may face c hallenges associated with climate change and should be aware of the
SWRP process. They have established the Washoe Environmental Protection Department (WEPD) which
is responsible for carrying out protection of the natural and cultural resources and management for lands
within the traditional territory and over 73,500 acres of trust and fee lands. A current WEPD project aims
to identify the risks and vulnerabilities of the Tribe, Tribal Communities, and environmental resources
related to climate change. These include more extreme weather events, higher temperatures, changes in
timing and amount of precipitation, reduced snowpack, longer growing seasons, increased wildfire,
increased pest infestations, changes in native plant and animal species, decreases in l ocal air and water
quality, and increases in invasive species, all of which may affect the health, safety, economic development,
ability of Tribal members to collect/ hunt native plants and animals, and sovereignty of the Washoe Tribe.
The Washoe Tribe wa s engaged through direct communication between the SWRP development team and
contacts from the Washoe Tribe.
ENVIRONMENTAL INJUSTICE (SWRP GUIDELINES SECTION F.VI)
The USEPA has developed a screening tool to identify Environmental Justice (EJ) concerns (EJSCREEN
Maps, Version 2017 accessed at https://ejscreen.epa.gov/mapper/). This tool identifies Environmental and
Demographic indicators that indicate where EJ concerns could arise but does not include the capability to
identify environmental justice concerns related specifically to stormwater or dry weather runoff. The tool
was used, in conjunction with local knowledge of stormwater related issues, to help identify whether there
were runoff related environmental justice issues to address in the SWRP. While there are some minority
and low-income populations within the SWRP Region (e.g., portions of the Town of Truckee, South Lake
Tahoe, and Kings Beach), there are no apparent runoff -related issues occurring within these distinct
areas. Stormwater and dry-weather runoff does not put disproportionate stress on areas with minority or
low-income populations, rather impacts from stormwater runoff occur throughout urbanized areas within
the SWRP Region (SWRP Guidelines Section F.VI).
ENGAGEMENT & COMMUNICATION SCHEDULE (SWRP GUIDELINES SECTION
F.VII)
Previous public engagement
A draft of the full SWRP was completed in October of 2017. It was posted on the Tahoe RCD website
(http://tahoercd.org/stormwater -resources -plan/) in November 2017 prior to the two public forums. All
relevant entities, including stakeholders (see Section B), specific audiences, and the general public were
invited to comment on the document during the review period from December 3, 2017 through January 3,
2018. Public comments were solicited through an Excel spreadsheet on Tahoe RCD’s website, and were
reviewed and incorporated into the document as appropriate.
The two public forums were intentionally scheduled at the beginning of the public draft comment period
and occurred in South Lake Tahoe on December 6th (in basin) and in the Town of Truckee on December 7th,
2017 (out of basin). They provided an overview of the SWRP, focusing on the importance of the document
and why it was developed as well as giving clear guidance on how to provide comments on the draft. The
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forums also allowed for public interaction with the implementing jurisdictions to discuss concerns, relevant
projects, or other public needs (SWRP Guidelines Section F.VII.). All relevant entities, including
stakeholders (see Section B), specific audiences, and the general public, were invited to the public forums.
Invitations to attend the public forums and comment on the draft SWRP were sent directly to the relevant
entities via email and the general public through The League to Save Lake Tahoe’s contact list, posted on
Tahoe RCD’s and implementing agencies social media platforms, and advertised in online news media and
TRPA’s website 30 days in advance. Two email reminders to provide comments on the draft and attend
the forums were sent one and two weeks prior to the forums.
Postings on Social Media
TRPA’s Facebook page (https://www.facebook.com/voiceforlaketahoe)
TRPA’s Twitter page (https://twitter.com/TahoeAgency)
Tahoe RCD’s Facebook page
(https://business.facebook.com/tahoercd/?business_id=10153455499298055)
▫ This post was shared on the following Facebook pages: Lake Mead Quagga updates, USFS
Lake Tahoe-basin Management Unit, Keep Tahoe Blue, Official City of South Lake Tahoe,
Drink Tahoe Tap, South Lake Tahoe, and Truckee.
News Media online content
Tahoe Daily Tribune “Community Briefs Section”
Lake Tahoe This Week’s event calendar
Moonshine Ink Tap Calendar
Other online content
TRPA’s public workshop online (http://www.trpa.org/public-workshops-on-stormwater-
resource -plan -december -6-7/)
Attendance at the public forums was minimal, but discussions during the overview presentation were
positive and attendees were pleased with the opportunity to engage with representatives from their
respective jurisdictions regarding stormwater projects that affect them.
Future public engagement
Any future changes to this plan or the implementation of the SWRP require public engagement. In the
unlikely case that revisions are necessary, the public will be engaged according to the engagement methods
used in the development of the SWRP outlined above.
The SWRP adaptive management process includes a public meeting to review all proposed changes to the
SWRP. Notice of this meeting will be publicly posted and a meeting report will be publicly available.