Water Management


Water Management staff manage three levee systems, implement storm water pollution prevention programs, and lead or provide technical assistance for various projects involving water resources. Levee system management and stormwater programs are continual responsibilities, while other projects are developed based on available funding, needs, and opportunities. Funding for Water Management comes from the County’s General Fund and federal and State grants. Other typical Water Management projects include habitat restoration, flood risk reduction, consultation on dam removal projects, and participation in regional planning initiatives involving water resources.

Contact Us

  1. Water Management

    1106 2nd St.
    Eureka, CA 95501 

    Staff Directory

  1. Levee and Flood Management
  2. Stormwater Program
  3. Sea Level Rise
  4. Klamath Settlement Agreements
  5. Special Projects
  6. Groundwater


Redwood Creek Levee (Orick)
The Redwood Creek Flood Control Project consists of a system of two earthen embankment levees along the lower 3.4 miles of Redwood Creek. The project was constructed by the U.S. Army Corps of Engineers from 1966 to 1968 to protect the community of Orick from floodwaters, in response to a series of flood events that occurred in 1950, 1953, 1955 and 1964. Construction included excavation and enlargement of the channel to a target geometry and placement of earthen levee embankments along each bank. Humboldt County performs levee operation and maintenance.

Redwood Creek Estuary Restoration and Levee Rehabilitation Conceptual Design Project (2012-2014)

Humboldt County completed a planning study which developed conceptual designs for a multiple-objective project on lower Redwood Creek and estuary that would achieve estuary restoration and levee rehabilitation. Funding was provided by the California Department of Fish and Wildlife (formerly Department of Fish and Game) through the Fisheries Restoration Grant Program. The approach to this planning study focused on facilitating stakeholder dialogue and improving the understanding of natural processes, desired conditions, and potentially feasible project concepts. The final report is posted here under the following title: Redwood Creek Estuary Restoration and
Levee Rehabilitation Conceptual Design Project. 

Construction of the Flood Control Project caused major physical changes to the lower reach of Redwood Creek and its estuary. Estuary volume has been reduced by over one-half of its pre-levee size due to sediment deposition, and fish habitat and water quality have been severely impaired. The net result has been a reduction in the ecological function of the estuary in terms of productivity and survival of fish and other aquatic species. Restoration of hydraulic, sediment transport, and floodplain processes is needed to help the estuary regain some of its former form, function, resiliency, and productivity.

The Flood Control Project is impaired by the deposition of large volumes of sediment, which has reduced the project’s flood capacity from the level of protection specified by Congress. Construction of the levees also reduced the ability of North and South Sloughs to flush sediment, which contributes to flooding of adjacent privately owned pastures and public roads. A fundamental rehabilitation of the Flood Control Project is needed to accommodate sediment inflow and achieve an acceptable level of flood protection that can be sustained with normal maintenance. Improvements are needed to regain active status in the Corps of Engineers Rehabilitation and Inspection Program and achieve certification and accreditation on the FEMA Flood Insurance Rate Map.

The lower Redwood Creek valley contains privately owned agricultural land adjacent to the Flood Control Project. Conceptual designs were developed with the goal of maintaining agricultural productivity and limiting the net loss of agricultural land use to the greatest extent possible while meeting other project goals. The project will need to find an acceptable balance between agricultural productivity, ecological restoration, and flood protection benefits. It is assumed that affected private landowners would be fairly compensated for impacts associated with levee modifications. In addition, the project would need to be consistent with the resource protection and preservation responsibilities of the National Park Service for affected federal land in Redwood National Park.

Recommended next steps include continued stakeholder dialogue; additional data collection and technical studies to evaluate the effectiveness of the conceptual alternatives identified in this report; and continued efforts to obtain a Congressional appropriation for the Army Corps of Engineers to perform a General Investigation Study.

Mad River Levee (Blue Lake)

The Mad River Flood Protection Project is located near the confluence of the Mad River and the Mad River North Fork, along the right bank of each waterway for a total length of 1.6 miles, near the Hatchery Road bridge at the southern end of the city of Blue Lake. The levee was constructed in phases by the Army Corps of Engineers starting in 1954 and reaching completion in 1963. The levee is composed of an earthen embankment with rock-slope protection on the river side. Humboldt County and the City of Blue Lake share responsibility for levee operation and maintenance.

Blue Lake Levee Evaluation Project (2013-2015)

Humboldt County and City of Blue Lake initiated a geotechnical investigation with financial assistance from the Department of Water Resources’ Local Levee Assistance Program to characterize subsurface soil conditions and analyze levee performance. The project will assess the stability of the levee embankment and foundation and determine the potential for settlement, seepage, underseepage, or erosion to cause instability under base flood (1%-annual-chance flow) conditions. The results of the project will assist Humboldt County and the City of Blue Lake in assessing the public safety risks associated with the levee and in determining whether the levee meets the embankment and foundation stability requirements of FEMA’s National Flood Insurance Program standards at 44 CFR 65.10. The final report is posted here under the following title: Blue Lake Levee Geotechnical Evaluation Project City of Blue Lake & Humboldt County California. In addition, a technical memorandum with supporting hydraulic information may be downloaded Here

Eel River Levee (Fortuna)
The Eel River Flood Control Project at Sandy Prairie is located along the right bank of the Eel River, with extensions along Strongs Creek and the Van Duzen River, near the city of Fortuna. The levee was constructed by the Army Corps of Engineers and completed in 1959. The total length of levee is approximately four miles.

Floodplain Mapping: 
In 2011, Humboldt County received a grant from the Federal Emergency Management Agency (FEMA) to perform detailed hydraulic analyses and floodplain mapping for the communities of Orick and Blue Lake which are each protected by levees.  Levees are critical infrastructure for the protection of life and property, and floodplain maps are important tools for representing and communicating the risk of floods.  The standards for analyzing and mapping the flood hazards behind a levee are being updated by FEMA.  Areas mapped as Zone A (Special Flood Hazard Area) on the Flood Insurance Rate Map are subject to special building standards and may be subject to flood insurance requirements. The work products from this project will be incorporated by FEMA into the updated Flood Insurance Rate Map and Flood Insurance Study for these communities which are expected to be issued by FEMA in 2015.

Humboldt Waterways Poster