Lake Tahoe, California and Nevada

Stormwater Runoff Management in the Lake Tahoe Basin


Lake Tahoe, California and Nevada
Key Water Quality Concerns

Excessive sediment and nutrients (nitrogen and phosphorus),
water clarity

Stakeholder Involvement Techniques

•	Stakeholder comment process

•	Public comment period on documents

•	Annual public meetings

•	Stakeholder involvement in implementation

•	Transparent website

•	Scientific advisory council

Case Study Issues of Interest
Type of Point Sources

Jl|jL Municipal Separate Storm Sewer System Discharges

fll 1 Inle

Construction Site Stormwater Discharges

Q n

Industrial Facility Stormwater Discharges
Type of Watershed-Based Permit or Approach

Multisource Watershed-Based Permit

Highlighted Approach(es)

Implementation of Total Maximum Daily Loads or

Other Watershed Pollutant Reduction Goals
7Coordinated Watershed Monitoring

Watershed-Based Permitting Case Study

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Lake Tahoe is one of the most iconic water
bodies in North America. Its exceptionally
clear water and distinctive blue coloring, set in
mountainous terrain, make it a unique
resource. Bordering both California and
Nevada, Lake Tahoe is critical to many
functions in the area, including drinking water,
recreation and tourism, agriculture, and
fisheries and wildlife habitat. California has
designated Lake Tahoe as an Outstanding
National Resource Water, one of two water
bodies in the state to receive that protection.
Nevada has designated it as a waterbody of
extraordinary ecological or aesthetic value.

Unfortunately, Lake Tahoe faces some of the
same water quality challenges as other water
bodies. Development in the watershed has
increased as tourism has become an
important part of the local economy, leading
to increased urbanization and more
stormwater runoff. Over time, the clarity of the
water has declined and algal growth has

Several organizations work to protect this
high-value water body. California's Lahontan
Regional Water Quality Control Board
(Lahontan Water Board) and the Nevada
Division of Environmental Protection (NDEP)

v=/EPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

are the state resource agencies.1 With the U.S. Congress's consent, the two states formed the Tahoe
Regional Planning Agency (TRPA) through a bi-state compact, which developed (and now
implements) a comprehensive plan to protect the Lake Tahoe watershed and enforce local ordinances.
To address water clarity and algal issues, the states also developed total maximum daily loads (TMDLs)
for fine sediment particles, nitrogen, and phosphorus. Local, state, federal, and private partners work
to implement the TMDLs to achieve the mid-range and long-range water quality goals established by
the TMDLs.

The states and TRPA determined early on that a watershed-based approach was the best way to
overcome these challenges. By addressing water quality concerns in both states, coordinating
programmatic goals, and leveraging resources, Lake Tahoe is on the path to recovery.

This case study provides an overview of the variety of programs and approaches used to protect and
enhance Lake Tahoe, with a focus on the role of watershed-based permits for stormwater runoff.


The watershed-based approach to improving water quality in Lake Tahoe has multiple elements. Two
of these elements form the superstructure of the various ongoing efforts and provide direction for
other programs and activities.

•	TRPA and the Lake Tahoe Regional Plan. TRPA was formed in 1969 with the charge of
coordinating planning and development, regulatory enforcement, and implementation of
environmental (and other) programs for the watershed. As part of this work, TRPA implements the
Lake Tahoe Regional Plan, which uses an adaptive management approach and is intended to
balance environmental protection and economic development. Last updated in 2022, the Regional
Plan establishes environmental quality thresholds in 10 key areas, including water quality. The
water quality thresholds set numeric standards for water transparency and phytoplankton
productivity in the main body of the lake, as well as standards for tributaries and surface runoff.
The thresholds also include non-numeric management standards for pollutant load reductions,
groundwater, and aquatic invasive species. The Regional Plan addresses these thresholds by
implementing restoration projects under the Environmental Improvement Program and enforcing
various land use policies in the watershed (e.g., Policy WQ-2.2, which prohibits the discharge of
sewage into the lake).

•	Lake Tahoe TMDLs. California and Nevada co-developed TMDLs to address impairments in Lake
Tahoe for fine sediment, phosphorus, and nitrogen, which were approved by EPA in 2011. The
TMDLs established overall pollutant reductions of 65 percent, 35 percent, and 10 percent,
respectively. The TMDLs also included an interim goal, known as the Clarity Challenge, of about
half of the overall load reduction to improve visibility to a depth of 80 feet. The interim pollutant
load reduction goals for the entire watershed would be met over 15 years, followed by a five-year
monitoring period.2 The TMDLs identified urban stormwater runoff as the primary source of fine
sediment and outlined control measures such as land management practices, stormwater runoff
source control, and treatment of runoff from roads and parking lots. California and Nevada also
developed procedures to track pollutant reduction progress and adaptively manage TMDL

1	The Washoe Tribe is also located in the area and has a long history of promoting water quality protection.

2	The full implementation of the TMDLs is expected to take about 65 years. Setting an interim goal helps to make measurable
progress while long-term improvements are made.

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

Under these elements are a number of other programs, including the National Pollutant Discharge
Elimination System (NPDES) permitting program, with the goal of restoring and maintaining water
quality in Lake Tahoe. California manages stormwater pollution in the Lake Tahoe watershed via three
watershed-based general permits: one for municipal stormwater from the City of South Lake Tahoe
and El Dorado and Placer Counties, a second for construction site runoff, and the third for stormwater
from marinas. California has also issued a statewide permit for stormwater discharges from the
California Department of Transportation (Caltrans) municipal separate storm sewer system (MS4).
Together, these permits address the major sources of urban stormwater pollution in the watershed.

Nevada uses a different approach to address urban runoff. NDEP has developed Interlocal
Agreements (ILAs) with the three major implementation partners in the watershed: both counties that
border Lake Tahoe, as well as the Nevada Department of Transportation (NDOT). These agreements
recognize partners' historic efforts to improve water quality and aim to provide a flexible and
collaborative mechanism for implementing the TMDLs. NDEP is also working with California, TRPA,
and EPA on specific efforts to improve water quality in the nearshore areas, which are most visible to
the public and most frequently used for recreation.

Together, California and Nevada have created the Lake Clarity Crediting Program, which measures the
progress of the implementation of the Lake Tahoe TMDL, including tracking water quality
improvements, reporting accomplishments, and assessing implementation progress and program
effectiveness. A 2022 report that evaluated progress against the 10-year milestones indicated that the
partners were successful in achieving the 10-year load reduction goals. These efforts have largely
halted the decline in water clarity, as clarity has remained relatively stable for the past 20 years.


California and Nevada have taken different approaches to reducing urban stormwater pollution in the
watershed. California primarily uses a permit-driven approach, while Nevada's primary approach
provides implementation details in State/local agreements. The two states, in combination with TRPA,
have also developed programs that focus on restoring water quality and tracking, reporting, and
assessing implementation of the TMDLs. The primary elements of each program are described in more
detail below.

California: General Permit for Municipal Stormwater


The Renewed Waste Discharge Requirements and National Pollutant Discharge Elimination System
(NPDES) Permit for Storm Water/Urban Runoff Discharges from El Dorado County, Placer County, and
the City of South Lake Tahoe Within the Lake Tahoe Hydrologic Unit (NPDES Permit No. CAG616001)
addresses stormwater from urban areas. Runoff from all urbanized areas within the permittee's
jurisdiction (and within the Lake Tahoe watershed) is covered under the permit, including stormwater
from MS4s and pollutants from winter roadway operations. The permit implements the Lake Tahoe
TMDLs and the Water Quality Control Plan for the Lahontan Region (Basin Plan) by requiring
development of Storm Water Management Plans (SWMPs) and Pollutant Load Reduction Plans
(PLRPs), which describe how proposed operations and maintenance efforts will meet the required load


The TMDLs established a phased implementation approach, with a 15-year timeline for reductions and
a five-year monitoring period. The current permit, issued in 2017, represents the second five-year

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

period of the reduction phase. As a result, the permit also has an interim compliance goal. The
required jurisdiction-specific reductions are based on a modeling effort by the permittees. The
permittee's SWMP must include components that address construction site runoff; commercial,
industrial, municipal, and residential site runoff; stormwater facility inspections; illicit discharge
detection and elimination; new development and redevelopment; public education; and municipal
personnel training and education. The required reductions and proposed improvement projects are
incorporated into a PLRP, which identifies specific subwatersheds and activities that must be
completed to achieve the load reduction goals. Compliance and progress tracking are accomplished
through a collaborative system (including the Lake Clarity Crediting Program and the associated Lake
Tahoe Info Stormwater Tools3) that tracks installed projects, baseline credits, and other factors.

California: General Permit for Construction Activities


The General Waste Discharge Requirements and National Pollutant Discharge Elimination System
Permit for Storm Water Discharges Associated with Construction Activity in the Lake Tahoe
Hydrologic Unit, Counties of Alpine, El Dorado, and Placer (NPDES Permit No. CAG616002) addresses
stormwater runoff from construction activities. Specifically, it covers construction activities at sites
where land disturbance is 1 acre or greater, or where smaller disturbances are part of a larger
development plan. The permit is based on the statewide NPDES General Permit for Storm Water
Discharges Associated with Construction and Land Disturbance Activities but is substantially more
stringent due to the sensitivity of Lake Tahoe, the elevation, and the need to implement the TMDLs.


This permit includes many of the elements of the statewide general permit and is also consistent with
the national effluent limitation guidelines and standards for the construction and development point
source category. However, the Lake Tahoe permit is more stringent and prohibits certain discharges,
includes additional effluent limits, and requires more frequent inspections.

The permit specifies that stormwater should be allowed to infiltrate at the site to the greatest extent
possible. The permit prohibits several types of discharges, including non-stormwater discharges into a
floodplain. Water that does discharge from the site is subject to effluent limits for total nitrogen, total
phosphorus, total iron, turbidity, grease and oil, and pH that are based on water quality standards for
Lake Tahoe. Required BMPs include overall site management, sediment and erosion control measures,
and dewatering controls. Inspections are required weekly (as opposed to monthly in the statewide
permit). Post-construction requirements include on-site infiltration for runoff from a 20-year, 1-hour
storm. Additional monitoring is required for any restoration projects that are installed, including
vegetation surveys and an assessment of erosion control structures.

California: General Permit for Marinas


The General Waste Discharge Requirements and National Pollutant Discharge Elimination System
Permit for Storm Water Runoff Associated with Marina Operations in the Lake Tahoe Hydrologic
Unit—El Dorado and Placer Counties (NPDES Permit No. CAG616003) addresses discharges from
marina owners and operators. There are 12 marinas on the California portion of the lake; a general
permit was a logical choice to address a group of facilities with similar operations and streamline the
permit application process for both the marina owners and the Lahontan Water Board. Any industrial

3 The tools webpage has both a public-facing page and a password-protected interface where the localities can enter data on
load reductions.

EPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

or minor construction activities (not including dredging, which was removed in the 2016 permit) that
disturb less than 1 acre of land area within the watershed would be covered. Construction projects
disturbing greater than 1 acre would need coverage under an individual permit or other general


The application requires a Notice of Intent and several other documents—either a Storm Water
Pollution Prevention Plan or a BMP Project Plan, plus a Marina Pollution Prevention Plan, a Discharger
Monitoring Plan, and a Marina Surface Water Monitoring Plan. These documents describe the BMPs
that the permittee will implement to meet the discharge requirements in the permit, as well as how
the permittee will comply with monitoring and reporting requirements.

Generally, the permit requires marinas to provide on-site infiltration for runoff from a 20-year, 1-hour
storm. If the permittee does not, then it is subject to effluent limitations in the permit. The limits,
which implement water quality standards for Lake Tahoe established in the Lahontan Water Board's
Basin Plan, include total nitrogen, total phosphorus, total iron, turbidity, grease and oil, and pH.
Alternatively, if the permittee discharges stormwater to a municipality or state highway department,
the municipality must be able to document that its treatment capability is sufficient to meet its own
pollutant load reductions. The permit also includes numeric benchmark levels for other pollutants
(including total suspended solids) that ensure BMPs are properly functioning.

The permit also includes extensive monitoring, inspection, and reporting requirements. Marina owners
must conduct visual inspections of their facility at least monthly, with a comprehensive inspection
once per year. They must also visually inspect the stormwater discharge four times per year and
conduct stormwater sampling twice per year. Marina owners are required to conduct additional
benchmark monitoring at least quarterly to confirm that BMPs are functioning properly. Lastly,
marinas must conduct surface water monitoring of the receiving water.

California: Statewide Stormwater Permit for the Caltrans MS4


The Statewide Stormwater Permit and Waste Discharge Requirements for State of California
Department of Transportation (NPDES Permit No. CAS000003) addresses stormwater discharges from
the Caltrans MS4. Caltrans owns and operates tens of thousands of miles of roads and other
transportation infrastructure across the state, including the associated storm sewers. In addition to
requirements that apply statewide, the permit includes requirements for implementing the Lake Tahoe


Runoff from roadways is a significant source of sediment loads to Lake Tahoe, making reductions
from this source category critical to improving water quality. The permit includes a schedule for
meeting the required fine sediment particle, total phosphorus, and total nitrogen load reductions and
requires Caltrans to develop and implement a Pollutant Load Reduction Plan for meeting the required
reductions. The permit also requires Caltrans to participate in the Lake Tahoe Regional Stormwater
Monitoring Program or an equivalent program developed by Caltrans.

The permit requires Caltrans to achieve load reductions in California portions of the Lake Tahoe
watershed of 71 percent, 50 percent, and 46 percent for fine sediment particles, total nitrogen, and
total phosphorus, respectively, by August 16, 2076 (i.e., 65 years after the effective date of the TMDLs).
In the interim, the permit requires incremental load reductions to be achieved at each five-year
milestone. The 2022 permit represents the third five-year TMDL implementation period and requires

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

Caltrans to meet load reductions of 34 percent, 21 percent, and 19 percent for fine sediment, total
nitrogen, and total phosphorus, respectively, by September 30, 2026 (i.e., the 15-year load reduction

In its Pollutant Load Reduction Plan, Caltrans must describe how it will meet specified reductions by
2026. The plan must include several elements, including the following:

•	A baseline load estimate.

•	A list of catchments where pollution reduction activities are expected to take place.

•	A list of activities to reduce pollutant loads in those catchments.

•	An analysis of a representative catchment demonstrating the expected pollution reductions.

•	A schedule for achieving reductions.

•	A discussion of how Caltrans will annually assess progress in reducing loads.

Nevada: Interlocal Agreements


NDEP has opted to use an agreement-based approach to implement the Lake Tahoe TMDLs. It has
established ILAs with Douglas and Washoe Counties and NDOT. These five-year agreements
correspond to the implementation schedule of pollutant reduction milestones from the TMDLs. 2021
marks the 10-year implementation milestone, which calls for a 21 percent reduction in fine sediment
loading and 14 percent reductions in phosphorus and nitrogen loading in urban stormwater. The 15-
year milestone will require a 34 percent fine sediment load reduction. The ILAs also use the Lake
Clarity Crediting Program to track and verify the effectiveness of these pollution controls.

Douglas and Washoe Counties are also permittees under Nevada's NPDES General Permit for
Discharges from Small MS4s (NPDES Permit No. NVS040000), and NDOT is subject to an individual
permit for its MS4 discharges (NPDES Permit No. NV0023329). The general permit establishes general
requirements for permittees to document that control measures are consistent with any applicable
TMDL WLAs and determine whether the stormwater controls are adequate to meet the WLAs. NDOT's
permit specifies that NDOT shall comply with all requirements set forth in its ILA and suggests that a
more regulatory approach may be implemented if NDOT breaches the ILA.


The ILAs contain specific obligations and commitments to ensure that implementation remains on
track. The counties maintain a Stormwater Load Reduction Plan that identifies specific actions or
improvement projects that will be accomplished in the term of the ILA. The ILAs also lay out the
inspection, monitoring, and reporting responsibilities. Annual reports describe the specific pollutant
controls implemented and progress toward meeting milestones (typically expressed as "credits" for
completing a given project).

Watershed-Wide: Nearshore Water Quality


The nearshore environment is often the portion of the lake the public sees the most and where water
quality issues are the most apparent. Reductions in water clarity and increased algal growth remain
problematic in the nearshore waters, as well as concerns over invasive species and degraded aquatic
habitat and communities. Both California and Nevada have developed specialized programs and
materials to focus on the nearshore waters.

EPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe


The Nearshore Resource Allocation Program (NRAP) researches and monitors nearshore conditions
and processes to inform management actions. NRAP developed six specific focus areas for study:
algae, nearshore clarity, public health, ecological community structure, aquatic invasive species, and
trash. NRAP implements several monitoring programs related to these focus areas, including
phytoplankton, periphyton, nearshore turbidity, aquatic invasive species, and deep-water plants

California, Nevada, TRPA, and EPA collaborated to develop outreach materials to educate the public
on the nearshore waters, including a graphic that shows the many sources of pollution to the lake and
the effects they can have on water quality. They also developed a brochure with information about
programs to control invasive species, ongoing monitoring efforts, and a list of ways private citizens
can help with the cleanup effort.

The Lahontan Water Board has also established the Lake Tahoe Nearshore Water Quality Protection
Plan (updated in 2018) to analyze monitoring data, assess indicators of threats to human health, and
identify research needs.

Watershed-Wide: Lake Clarity Tracker


As part of the long-term effort to improve water quality, California and Nevada have developed a
comprehensive program to track, report, and assess progress in implementing the TMDLs. The Lake
Clarity Tracker is the central hub for information related to the TMDL program, including
implementation results and operational procedures that enable performance assessment and
continuous improvement over time.


The tracker currently has an inventory of more than 200 individual projects that have been completed,
are underway, or are planned for future implementation. Localities upload information to demonstrate
progress and plan for future budgetary needs. Performance results are presented by the source
categories from the TMDLs: urban uplands (see Figure 1 below as an example), forest uplands,
atmospheric deposition, and stream channel erosion. Progress in the urban sector is tracked by each
project earning "credits" (via the Lake Clarity Crediting Program; see the text box below) toward
meeting the implementation goals.

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

Figure 1. Lake Clarity Credits Awarded by Year (Source: Lake Clarity Tracker)

o Lake Clarity Credits Secured

By: | Jurisdiction


¦ Target Caltrans CSLT
| Washoe County, NV

I Douglas County, NV El Dorado County, CA NDOT Placer County, CA






2018	2019

Water Year



Public Involvement

In addition to being a drinking water source for many communities, tourism and recreation are a
haiimark of the watershed, so the vaiue of ciean water is paramount. The public continues to piay a
huge roie in developing and implementing programs for clean water. In addition to comment periods
on the TMDLs, draft permits, and triennial review of water quality standards in the Basin Plan, public
involvement opportunities include:

•	The Lahontan Water Board and Nevada DEP encourage the public to provide input using a
feedback form on the Lake Clarity Tracker. Program managers solicit TMDL stakeholders to
provide input to improve program operations, including new scientific findings and technical
information that support program improvement adjustments, as well as input on annual program
priorities, objectives, and actions. Program managers track public comments, discuss them with
executives, and respond to them. The Lake Tahoe TMDL Program captures this information in a
Findings & Program Recommendations Memo that it issues each winter. Program managers may
also host an annual meeting, if warranted.

•	Localities create and enforce on-the-ground policies, ordinances, and other mechanisms to
control pollutants. In doing so, the localities work with their residents and businesses to develop
and implement these controls. In some cases, these localities may solicit public comment. In
others, the locality may be more involved with outreach or education components, which is also
an element of public involvement.

•	The Lake Clarity Tracker provides a transparent method for the public to monitor progress toward
meeting the goals of the TMDLs. The Lake Clarity Tracker also provides details on more than 200
individual improvement projects. These data show that the program has local sponsors, technical
partners, and funding sources.

•	The TMDL Performance Report is an annual progress report that highlights basin-wide
accomplishments toward reducing pollutant loads from urban and non-urban sources. The report
is intended to improve program accountability and retain support for continued investment of
public dollars for water quality improvements.

In short, the public is involved at every step of water quality improvement efforts, from the
programmatic and planning level down to the execution of individual BMPs and specific projects.

EPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

Program and Permit Effectiveness

Many of the programs discussed in this case study have been in an implementation stage for a decade
or more. As a result, it's possible to iook back and see the improvements that have been realized,
including improved water quality, increased program efficiency, and more equitable and consistent
outcomes. Below are some of the results of these programs:

•	The Lake Tahoe TMDL Program has generated effective coordination between state regulators,
implementers, and funding entities. The crediting program has offered significant benefits, such as
incentivizing jurisdictions to prioritize load reduction efforts on actions and areas where the most
environmental benefit can be realized.

•	The TMDL Management System has resulted in numerous improvements that have helped
streamline implementation efficiency and overall program effectiveness.

•	Localities have greatly improved their inspection and maintenance protocols for pollutant
controls, ensuring continued performance overtime.

•	The development of the Lahontan Water Board's three general permits has streamlined the
permitting process, saving resources for agencies and improving the process for permittees.

•	Ongoing monitoring and inspection requirements ensure that the control measures in each
general permit are properly functioning.

•	Annual reports required by each of the Lahontan Water Board's general permits and NDEP's ILAs
provide useful information to track progress, identify problem areas, and strategize how to meet
future credit targets. These documents, in addition to the program website, provide transparency
to the public and allow for greater stakeholder participation.

•	As noted above, the partners are meeting their targets for improving Lake Tahoe; the 10-year load
reduction milestone was achieved in 2021. Figure 1 above showed the progress in the urban
upland sector, where the target number of lake clarity credits for 2021 was 2,686 and the partners
implemented a total of 2,987 credits. Every jurisdiction met the targets, showing great teamwork.
Urban uplands are also meeting or exceeding goals for nitrogen and phosphorus load reductions.

•	Despite having a different approach than the NPDES MS4 general permit on the California side of
Lake Tahoe, NDEP's ILAs have achieved the same kinds of planning and implementation actions
on the Nevada side, resulting in equivalent levels of progress in implementing the Lake Tahoe

•	The TMDL Program is seamlessly integrated into the larger Lake Tahoe Environmental
Improvement Program, managed by TRPA. This program works to achieve other important basin-
wide goals, including reducing wildlife risk, restoring forest and ecosystem health, and combatting
invasive species.

Lessons Learned

After more than a decade of implementation experience, stakeholders can offer some insights into the
programs' performance. The primary response was simple: follow the science. The Tahoe Science
Advisory Council (an independent entity comprising academic and government representatives)
meets regularly to analyze lake clarity data, discuss new research, and advise program managers on
future activities. Before the Lake Tahoe TMDL was developed, program managers believed that algae
was the cause of the loss of clarity. However, program managers were quick to adapt to the TMDL's
findings and instead focus on fine sediments.

Maintaining flexibility is another key to the programs' success. As shown above, as more data become
available, approaches and goals may change. But on a more practical level, providing jurisdictions
flexibility when implementing the programs is critical. California and Nevada have chosen two very
different approaches, yet both have been able to achieve their goals. On a smaller scale, providing a

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

locality with a load reduction target and allowing them to choose how they meet that target can
provide an effective and efficient approach to achieving the needed reductions.

As noted above, although the localities met their 10-year load reduction goals, the water clarity in
Lake Tahoe seems to have plateaued. Adaptive management is vital to making continued progress;
this topic is an ongoing discussion among the agencies and the Tahoe Science Advisory Council.
Further study and analysis may refine the approach as the complexities of the system are better
understood. Similarly, it was mentioned above that the Lake Tahoe Regional Plan established numeric
and narrative environmental thresholds to address water quality across 10 different topic areas.
Stakeholders are currently working to develop numeric targets for the narrative thresholds, which will
improve implementation by providing more specific targets. Over the long term, decision-makers can
also consider the role of climate change and how it affects water clarity.

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe


California State Water Resources Controi Board (SWRCB). Statewide Storm water Permit and Waste Discharge
Requirements for State of California Department of Transportation. Effective January 1, 2023. issues/programs/stormwater/docs/caltrans/2022/unofficial adopted ord

California Lahontan Regional Water Quality Control Board (Region 6a). No date. Lake Tahoe TMDL Program. issues/proarams/tmdl/lake tahoe/.

California Lahontan Regional Water Quality Control Board (Region 6a). General Waste Discharge Requirements
and National Pollutant Discharge Elimination System Permit for Storm Water Runoff Association with Marina
Operations in the Lake Tahoe Hydrologic Unit—El Dorado and Placer Counties. Effective November 1, 2016. decisions/adopted orders/2016/docs/r6t 2016 0038 marina a

California Lahontan Regional Water Quality Control Board (Region 6a). General Waste Discharge Requirements
and National Pollutant Discharge Elimination System Permit for Storm Water Discharges Associated with
Construction Activity in the Lake Tahoe Hydrologic Unit, Counties of Alpine, El Dorado, and Placer. Effective
January 1, 2017. issues/programs/storm water/docs/r6t 2016 0010 cgp combi

California Lahontan Regional Water Quality Control Board (Region 6a). Renewed Waste Discharge Requirements
and National Pollutant Discharge Elimination System (NPDESJ Permit for Storm Water/Urban Runoff Discharges
from El Dorado County, Placer County, and the City of South Lake Tahoe Within Lake Tahoe Hydrologic Unit.
Effective June 17, 2017. decisions/adopted orders/2017/docs/r6t2017 0010 lake taho
e npdes.pdf.

California Lahontan Regional Water Quality Control Board (Region 6a). August 2018. Updated Lake Tahoe
Nearshore Water Quality Protection Plan. issues/programs/lake tahoe/nearshore/doc/nrshre rpt update.

California Lahontan Regional Water Quality Control Board (Region 6a). Meeting of October 6-7, 2021. Item 7,
Lake Tahoe Water Clarity and Lake Tahoe Municipal Stormwater Permit (Order R6T-2017-0010). info/agenda/2021/oct/item7.pdf.

California Lahontan Regional Water Quality Control Board (Region 6a) and Nevada Division of Environmental
Protection (NDEP). December 2014. Lake Tahoe TMDL Program Management System Handbook.

California Lahontan Regional Water Quality Control Board (Region 6a) and NDEP. August 2022. Lake Tahoe
TMDL Program 2022 Performance Report: 10-Year Review: A Decade of Meaningful Progress.

Nevada Division of Environmental Protection (NDEP). No date. Lake Tahoe Watershed.

NDEP. Deep Water Clarity. No date,

NDEP. November 2021. Douglas County Interlocal Agreement,
docs/Douglas County ILA.pdf.

NDEP. No date. Improving Lake Tahoe's Nearshore.

oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

NDEP. November 2021. NDOT Interlocal Agreement,
docs/NDOT ILApdf.

NDEP. No date. Nearshore Pollution. Tahoe Nearshore Pollutants Sources Effects.pdf.

NDEP. January 2022. Washoe County Interlocal Agreement,
docs/Washoe County ILA.pdf.

TRPA. Environmental Improvement Program. No date,

TRPA. February 2022. 2021 Findings & Program Recommendations Memo.

TRPA. Lake Clarity Crediting Program. No date.
TRPA. March 2021. Lake Clarity Crediting Program Handbook.

TRPA. No date. Lake Tahoe Clarity Tracker,

TRPA. No date. Lake Clarity Tracker Results.

TRPA. No date. Nearshore Resource Allocation Program.

TRPA. No date. Regional Plan,

TRPA. 2012. Threshold Standards and Regional Plan,
content/uploads/documents/archive/2/Adopted-Regional-Plan 20190722.pdf.

TRPA. No date. Stormwater Tools,

Tahoe Resource Conservation District. No date. Regional Stormwater Monitoring Program (RSWMP).

U.S. Environmental Protection Agency (EPA). No date. Lake Tahoe Water Quality Improvement Programs.

Permitting Authority Contact:

Mary Fiore-Wagner

State of California, Lahontan Regional Water Quality Control Board
Jason Kurchnicki

Nevada Division of Environmental Protection


Planning Agency Contact:

Dan Segan

Tahoe Regional Planning Agency


Program Information:



oEPA Watershed-Based Permitting Case Study — Stormwater Runoff Management, Lake Tahoe

EPA-833-F-22-002	March 2023