Elk River TMDL


In 1998 the North Coast Regional Water Quality Control Board (Regional Water Board) and the U.S. Environmental Protection Agency listed the Elk River Watershed under the Clean Water Act Section 303(d) as a sediment-impaired waterbody.

Sediment discharges and sedimentation exceeded the water quality objectives for sediment, suspended material, settleable matter, and turbidity resulting in adverse impacts to several beneficial uses, including domestic water supplies (MUN), agricultural water supplies (AGR), cold water habitat (COLD); spawning, reproduction and early development (SPWN); rare, threatened, or endangered species (RARE), and recreation (REC-1 and REC-2). Sedimentation has also resulted in conditions of nuisance, including elevated rates of annual flooding, loss of property, loss of use of property, loss of access to property, and risk to human health and welfare.


In 2016, the Upper Elk Sediment Total Maximum Daily Load Action Plan (Action Plan) was adopted by the North Coast Regional Water Quality Control Board (Resolution No. R1-2016-0017). The Action Plan was approved by the State Water Resources Control Board in 2017 (Resolution No. 2017-0046), and was approved by the Office of Administrative Law and approved by the United States Environmental Protection Agency in 2018.

The goals of the Action Plan are to achieve sediment related water quality standards, establish a sediment load, identify a process for assessing and implementing remediation and restoration actions, and describe a program of implementation.  The Action Plan was incorporated in the Water Quality Control Plan for the North Coast Region (Basin Plan) and identified three elements to achieve its goals: permitting of discharges of waste, an Elk River Recovery Assessment, and a Watershed Stewardship program. 

Additional information on each of these elements is included in the “Implementation” section below. Additional information on TMDLs is available from both the State Water Resources Control Board TMDL Program and the North Coast TMDL Program.

The three elements of the Elk River TMDL Action Plan (Action Plan) program of implementation are: waste discharge requirements (WDRs), an Elk River Recovery Assessment, and a Watershed Stewardship Program.

WDRs-The primary regulatory mechanism used by the Regional Water Board to control the nonpoint source pollution in the Elk River watershed.

WDRs have been in place since 2006 for Humboldt Redwood Company (HRC) and Green Diamond Resource Company (Green Diamond), the two commercial timber companies operating in the Elk River Watershed. The WDRs currently in effect were adopted in 2019 for HRC and in 2020 for Green Diamond.

Elk River Recovery Assessment (Recovery Assessment)- A non-regulatory assessment of sediment remediation and channel restoration activities, which in combination with sediment load reductions, are necessary to improve hydraulic and sediment transport in the Elk River. 

Funded by the State Water Resources Control Board, the Recovery Assessment was completed in 2019 by CalTrout with assistance from Northern Hydrology and Engineering (NHE) and Stillwater Sciences, and with the guidance of a Technical Advisory Committee. The Recovery Assessment uses models to assess watershed responses to reduced sediment loading from the upper watershed, and the implementation of various restoration approaches. It also provided the basis for the development of the Elk River Watershed Stewardship Program: Sediment Remediation and Habitat Rehabilitation Recovery Plan (Recovery Plan)

Funded by the Regional Water Board and completed in 2022 by CalTrout with technical assistance from NHE and Stillwater Sciences, the Recovery Plan builds on the tools developed in the Recovery Assessment. It serves as a blueprint for habitat restoration and recovery actions from just above the confluence of the North and South Fork Elk down to the Humboldt Bay.

Watershed Stewardship Program- A non-regulatory approach to engage stakeholders in developing collaborative planning to enhance conditions in the Elk River.

The Stewardship Program provides a framework for working with partners to develop and coordinate restoration and recovery actions, address health and safety concerns, and develop a Science and Coordinated Monitoring Workgroup. Stewardship Program goals are to:

  • Seek common ground among diverse participants.
  • Identify strategies and solutions to improve the hydrologic, water quality and habitat conditions of the Elk River, reduce nuisance flooding and improved public transportation routes during high water conditions, and improve residential and agricultural water supplies.
  • Promote coordinated science and monitoring.

The Regional Water Board has been working with partners to aid in watershed restoration and recovery. Key project partners include California Trout (CalTrout) Northern Hydrology & EngineeringStillwater SciencesHumboldt County, the California Department of Fish and WildlifeCalifornia Coastal Conservancy, the Elk River community, Humboldt Redwood CompanyGreen Diamond Resource Company and the Bureau of Land Management.

Health and Safety projects include identifying alternatives to reduce nuisance flooding including increased flooding along Elk River Road and addressing domestic and agricultural water supply needs to the upper watershed.

Between May 2022 and June 2023, three rounds of Elk River resident interviews were conducted by Regional Water Board staff. The open-ended interview questions were designed to address the topics of 100- year flood levels, road flooding, drinking water, and wastewater systems.  Participants were given an opportunity to share personal experiences on each of these topics and to provide any solutions they saw for the watershed. Information shared during the interviews will help with future health and safety project efforts.

Nuisance Flooding
In September 2020, the Regional Water Board funded a technical memorandum on that included extreme flood events up to the 1% annual chance flood i.e., the FEMA 100 Year Flood Plain. The 1% Annual Chance Flood Elevation Estimates for the Lower Elk River, Humboldt County (100-year Flood Memo), was completed by Northern Hydrology and Engineering and was distributed to Humboldt County flood protection authorities and made publicly available.

Elk River Road
In 2023 the Regional Water Board funded Humboldt County to complete a Project Study Report (PSR) for Elk River Road flooding.  A necessary first step, the PSR will identify solutions to address the road flooding along Elk River Road at Zanes Road, Berta Road and the flood curve (near the intersection of Wrigley Road and Elk River Road).

Drinking Water
Regional Water Board staff continues to work with state and local programs (e.g., Safe and Affordable Funding for Equity and Resilience (SAFER) Drinking Water Program, the Division of Drinking WaterDivision of Financial Assistance,) to find alternatives for sustainable drinking water solutions to the upper Elk watershed.

The Regional Water Board Elk River TMDL Action Plan supports long-term recovery through watershed restoration. Guided by the 2019 Elk River Recovery Assessment and the 2022 Elk River Recovery Plan, restoration project planning is currently underway in the lower portion of the watershed (identified as Planning Area 1 in the Elk River Recovery Plan).

With funding from the California Coastal Conservancy and technical support from the Regional Water Board, CDFW, and NOAA, the CalTrout Team is leading the development of proposed restoration projects. Additional project information can be found in the March 2023 Planning Area 1: 10% Design Report. A 65% Design Report is currently underway.

The Science and Coordinated Monitoring Workgroup will help to guide the development of a coordinated monitoring program framework that includes key monitoring questions and implementation strategies.  When formed, the workgroup will build upon existing monitoring efforts and management recommendations, including those in the Elk River Recovery Plan and the 2022 Upper Elk River Sediment TMDL 5-Year Review Staff Report.

The Elk River TMDL Action Plan establishes that the Regional Water Board staff evaluate TMDL implementation progress in 2021, 2026 and 2031. The first staff review  was presented to the Regional Water Board in August 2022 during the Upper Elk River Sediment TMDL 5-Year Review. Findings and recommendations are found in Sections 6.1 and 6.2 of the Staff Report.


    Regional Water Board Adopted TMDL Action Plan

    On May 12, 2016 the Regional Water Board adopted the Action Plan for the Upper Elk River Sediment TMDL as an amendment to the Water Quality Control Plan for the North Coast.  Staff provided the Board with a summary of the April 7 meeting and the clarifying edits to the TMDL Action Plan.  Board deliberations proceeded with the public record closed and no additional public comments.  The adopted TMDL Action Plan will next receive a hearing before the State Water Resources Control Board with appropriate notices given, undergo review by the Office of Administrative Law, then go to the US Environmental Protection Agency for final approval.

    May 12, 2016 Regional Water Board Hearing

    The April 7, 2016 hearing concluded without a decision of the Board. Certain edits to the Upper Elk River TMDL Action Plan were contemplated by the Board toward the end of the hearing on April 7, 2016. Staff has reviewed and refined those. The edits reflect minor changes requested by Board members to clarify 1) how hillslope indicators and targets are used to inform Board decision-making; 2) that a load allocation does not constitute an effluent limitation or a waste load allocation and that the Board has discretion in implementing it in WDRs, waivers or other actions to reduce and eliminate waste discharges; and 3) that staff will review the sediment source analysis for the Upper Elk River, sediment deposition in the impacted reach and Lower Elk River, and the need for a Lower Elk River sediment TMDL, in its five year reassessment using Recovery Assessment tools and other available data, as appropriate. These edits are not substantive and fall within the logical outgrowth of the content previously noticed for this item. As expressed on April 7, 2016, the public hearing on this agenda item has been closed and no new testimony or evidence will be accepted. The Board will resume its deliberations on this matter on May 12, 2016 at the Wiyot Community Center in Loleta.

    April 7, 2016 Regional Water Board Hearing, decision postponed

    A hearing to consider adoption of the proposed Action Plan for the Upper Elk River Sediment TMDL was held on April 7, 2016 at the Eureka City Council Chambers. The agenda for this hearing and audio recording can be found on our webpage at:

    The Action Plan for the Upper Elk River Sediment TMDL was Item 5 on the agenda.  The documents associated with this item were:

    February 5, 2016 Staff Workshop

    The Upper Elk River Technical Analysis for Sediment (technical report) represents a comprehensive assessment of sediment conditions and associated beneficial uses in the Elk River Watershed, and presents the best available and relevant science. The Technical Report describes the Elk River Watershed setting, the applicable regulatory framework, and desired watershed conditions. It further documents the sediment impairments, identifies and quantifies the sources of excess sediment, and estimates the sediment loading capacity of the system, distinguishing between current and future sediment loading capacity. Finally, the Technical Report proposes a TMDL for sediment as supported by the existing data, as well as a framework for implementation, monitoring, and adaptive management.
    Please Note: The documents available for public review and comments are 1. TMDL Action Plan and 2. Technical Report. Comments on the Technical Report submitted in association with review of the draft WDR for HRC need not be repeated as part of comments on the draft TMDL Action Plan. Commenters are requested to simply provide reference to any previously submitted comments.

    In July 2013, the North Coast Regional Water Quality Control Board (Regional Water Board) made available to the public via its website the Peer Review Draft Staff Report to Support the Technical Sediment Total Maximum Daily Load (TMDL) for the Upper Elk River (Peer Review Draft Staff Report). The document is accompanied by the peer reviewers' curricula vitae, their individual comment letters, and the Regional Water Board's responses to peer review comments.

    Public Comment Letters Received for Technical Report and Draft TMDL Action Plan:

    Jane Arnold

    Joel Fonner

    Nathan Madsen

    Ken Pimlott

    Christina Pasteris

    Gary Ryanearson

    Jerry Martien

    Jesse Noell

    Kristi Wrigley

    Lee MacDonald

    Lisa O'Keefe

    Matthew Turner

    Mike Miles

    Phillip Nicklas

    Rob DiPerna

    Sylvia DeRooy

    Wayne Whitlock

    Vivian Helliwell

    Janet Parrish

    Hank Seeman

    Available Documents - WDR

    The draft Elk River Sediment TMDL Action Plan includes a number of regulatory and nonregulatory measures to implement the proposed TMDL. Adoption of a Waste Discharge Requirement (WDR) for Humboldt Redwood Company (HRC) to control sediment discharges from HRC-owned timberlands in Upper Elk River in conformance with the TMDL is one of the proposed regulatory measures. Information regarding a draft WDR for HRC, public comments received, and other related information can be found in the link below.

    Available Documents - CEQA

    The primary regulatory component of the TMDL Action Plan(draft WDR for HRC) is subject to a separate public notice listed above. The draft WDR is accompanied by a draft Initial Study and Mitigated Negative Declaration (IS/MND) that analyzes potential impacts from the draft WDR, and identifies mitigation measures to reduce those impacts. If adopted, the MND satisfies CEQA requirements for the regulatory portion of the TMDL Action Plan applicable to HRC. Other implementation actions for upstream activities in Table 4 of the TMDL Action Plan are subject to various permitting structures that have existing CEQA coverage.
    The non-regulatory components of the TMDL Action Plan (i.e., instream remediation, channel restoration, and the Watershed Stewardship Program) also require CEQA coverage. As explained in the IS/MND for the draft WDR, the instream remediation, channel restoration and Watershed Stewardship Program may result in large projects that are beyond the scope of the MND. As explained in more detail in the public notice above, the Regional Water Board intends to rely on the Temperature Policy Substitute Environmental Documentation (SED) and Restoration Policy Addendum (Restoration Addendum) for CEQA compliance for the restoration components of the TMDL Action Plan.
    The SED includes a programmatic statement of overriding considerations if the State or Regional Water Board finds that a project's potentially significant, unavoidable environmental impacts could be acceptable in light of the benefits of attainment and protection of beneficial uses. The Regional Water Board will consider the collective CEQA documentation, including the draft WDR/ MND, Temperature Policy SED, and Restoration Addendum when considering the adoption of the TMDL Action Plan. Decision-makers will have the benefit of project-level CEQA review of any large-scale restoration projects.
    Substitute Environment Document (SED) for Temperature Policy:


    May 7, 2014 Regional Water Board Workshop

    There will be an informational workshop to update the Board, responsible parties and other interested persons on the development of the Total Maximum Daily Load (TMDL) and the Waste Discharge Requirements (WDR) for the control of nonpoint source waste discharges from timberlands in the Upper Elk River watershed. No formal action will be taken by the Board as this workshop. This is an opportunity for affected parties and interested stakeholders to address the Regional Water Board members and for the Board to provide policy direction to staff to inform the strategy for implementing the TMDL/WDR. The Executive Officer's Summary Report and the Workshop Agenda describes material to be covered at the workshop. The workshop will be held from 1:00-5:00 P.M., Wednesday, May 07, 2014 at the River Lodge Conference Center located at 1800 Riverwalk Drive in Fortuna, California.

    Sediment Total Maximum Daily Load for the Upper Elk River and Associated Documents

    Staff of the Regional Water Board developed the Peer Review Draft Staff Report to Support the Technical Sediment Total Maximum Daily Load for the Upper Elk River (Peer Review Draft Staff Report). Working with the Cal/EPA Scientific Peer Review Program, the Peer Review Draft Staff Report has undergone external scientific peer review of the scientific portions of the assertions, findings, and conclusions, including the soundness of the scientific knowledge, methods, and practices as presented in the Peer Review Draft Staff Report.
    Links to the Peer Review Draft Staff Report, a cover letter describing its context in the TMDL development process, the peer review comments, and staff responses to those comments are provided below. While staff welcomes informal comments from interested parties on the Peer Review Draft Staff Report and the Response to Comments, no formal public comment period will be initiated at this stage in the process.
    Over the coming months, staff will be working on revising the Peer Review Draft Staff Report for release in spring 2014 as the Public Review Draft TMDL Staff Report by:

    • Making revisions in response to the peer review comments, consistent with the revisions identified in the Response to Comments;
    • Developing more completely the implementation and monitoring chapters; and
    • Making revisions to support the adoption of an implementation program as described in the cover letter and Response to Comments.

    Concurrently, staff will begin the development of the draft Upper Elk WDR, the regulatory vehicle to control, prevent, and remediate the discharge of sediment from timber operations and associated activities in the Upper Elk River watershed. The Upper Elk WDR will be based on the fundamental scientific findings associated with the load allocations, targets, and implementation framework in the Peer Review Draft Staff Report. The implementation and monitoring chapters of the Public Review Draft TMDL Staff Report will be drafted consistent with development of the draft Upper Elk WDR. The draft Upper Elk WDR is scheduled for release at the same time as the Public Review Draft TMDL Staff Report in spring 2014. .


    November 16, 2013 Elk River Forum Sponsored by the Humboldt County Board of Supervisors

    On November 16, 2013, the Humboldt County Supervisors sponsored an Elk River Forum, in coordination with Friends of Elk River, and Redwood Community Action Agency. The Elk River Forum was held in response to a petition brought to the Supervisors by Elk River residents. Multiple speakers were arrayed and responded to questions from a panel. Panel members were: Kristi Wrigley (North Fork resident and apple farmer), Jesse Noell (South Fork resident), Scott Sherman (Berta Road, Mainstem resident), John Estevo (Mainstem Elk River dairyman), Mike Miles (Humboldt Redwood Company), and Gary Rynearson (Green Diamond Resource Company). Speakers included: Adona White (North Coast Regional Water Quality Control Board), Jack Lewis (Hydrologic Statistician), Jessica Hall (Humboldt Bay Keeper), Jim Robbins (California Department of Forestry and Fire Protection), Darren Mierau (California Trout), and Greg Blomstrom (Baldwin, Blomstrom, Wilkinson and Associates, Inc.). The audience included Elk River residents, two Humboldt County supervisors, environmental advocates, resource specialists, and representatives of public agencies. Links to the presentations made at the Elk River Forum are included below.

    Participants generated a list some Desired Outcomes resulting from watershed TMDL and other watershed recovery efforts.

    May 2, 2013 Regional Water Board Information Item on Upper Elk TMDL Development

    On May 2, 2013, during the Regional Water Board meeting in Eureka, there was an informational item on the status of the Upper Elk River Sediment TMDL development. Information related to this item may be found in the Executive Officer's Summary Report and Power Point Presentation.

    Elk River Recovery Assessment and Pilot Project Implementation

    The Regional Water Board received funding in 2013 from the State Water Resources Control Board's Cleanup and Abatement Account to conduct the Elk River Recovery Assessment to Restore Beneficial Uses and Abate Nuisance Flooding Conditions (Recovery Assessment) and conduct a Sediment Remediation Pilot Project (Pilot Project). The Recovery Assessment was designed to assess the fate and transport of fine sediment in the middle and lower reaches of the Elk River from the top of the depositional reach (upstream of the confluence of the North and South Forks) downstream to Humboldt Bay, commonly known as the Impacted Reach. The Recovery Assessment required the collection of sediment and hydraulic data which was used to populate a hydrodynamic and sediment transport model, which was used to evaluate the effects of three different management scenarios – existing conditions, reduced sediment loads, and a modified channel.
    The Pilot Project involved the mechanical removal of road base fill and the elevated approach to the Steel Bridge, which has served as an impediment to flood flows in the impacted reach. Modifying this feature has the potential to contribute to the improvement of floodplain hydrodynamics in this reach. This project was successfully completed (with funds from the State Coastal Conservancy) in the Fall of 2017.
    The end product of the Recovery Assessment is represented by the Elk River Recovery Assessment: Recovery Framework, completed in December 2018.