Floodplain Management

Nooksack floodplain cross section

The devastating November 2021 floods generated a lot of interest and questions about floodplain management in Whatcom County. Read below for a brief overview of the organizations and jurisdictions that work together to reduce flood risks to infrastructure like homes, businesses, and roads in our floodplains while also preserving the benefit of functional floodplains.

What is a floodplain?

Floodplains are low-lying areas adjacent to rivers, streams, and marine coastlines that are often accessed by flood waters. Floodplains play an important role in reducing the effects of seasonal high water by storing and slowing down excess water.

Floodplain Regulations

Regulations about what kinds of activities can be pursued in a floodplain falls to the city you live in or to Whatcom County if you live outside of city limits. These regulations include things like building codes and zoning in compliance with state floodplain management laws and the federal National Flood Insurance Program(NFIP). The Washington State Department of Ecology oversees consistent floodplain management for the state. The Federal Emergency Management Agency (FEMA)manages the NFIP and federal regulations. 

River Management

Whatcom County and the Flood Control Zone District

Flood Control Zone District (FCZD) covering all of Whatcom County was established in 1991. The FCZD has limited authority to manage flooding and storm water within the county. The Whatcom County Council and Executive are the elected governing body for the FCZD. In this role, they are known as the Board of Supervisors. The Board of Supervisors makes policy decisions and oversees the work of the FCZD. Staffing for the FCZD is provided by Whatcom County Public Works. A FCZD citizen advisory committee provides recommendations on flood hazard management and water resources plans, plan implementation, and budgets. These roles and responsibilities are specified in Whatcom County Code Title 100. All property owners in Whatcom County pay a Flood Control Zone District tax. These revenues go into a dedicated flood fund that the county uses to pay for flood control and surface water management services. 

Our River and Flood Division provides a wide variety of services related to Nooksack River management including:

  • Flood and alluvial fan hazard management planning–This includes the Lower Nooksack River Comprehensive Flood Hazard Management Plan, which is currently being updated through the Floodplain Integrated Planning (FLIP) Process. Some of the higher risk  alluvial fans have also been  assessed to evaluate hazards and reduce risk from catastrophic flood events at the base of steep mountain streams.
  • Flood hazard risk reduction projects–These projects are designed to reduce future flood damages. Examples include improving levees, building levee setbacks and overflow spillways, designating overflow corridors, and buying out properties with repetitive flooding. We also participate in the Floodplains by Design program with projects designed to reduce flood hazards, improve habitat, support agriculture, and increase the resiliency of our rural communities.  
  • National Flood Insurance Program (NFIP) administration–Affordable flood insurance is available to private landowners through the NFIP if the local jurisdiction participates in the program and adopts approved flood management regulations. Whatcom County, cities, and the Lummi Nation participate in the NFIP.

Subzones, Diking and Drainage Districts

FCZD subzones, diking districts, and drainage districts also have an important role in Nooksack River management and, more broadly, surface water management throughout the county. These special districts cover specific geographic areas within the county. Diking and drainage districts are independent jurisdictions outside of county government with their own elected officials. Subzones are a subset of the overall FCZD with their own citizen advisory committees providing recommendations on projects and spending within their boundaries. Property owners in these districts pay a fee to fund specific services within the district like levee maintenance and improvements, maintenance of drainage systems, or stormwater management programs. 

U.S. Army Corps of Engineers (USACE)

The FCZD participates in a federal levee management program known as Public Law (PL) 84-99. This program allows the USACE to conduct emergency repairs and provide cost sharing for rehabilitation of levees damaged by floods. The FCZD maintains approximately 30 miles of levees throughout Whatcom County to USACE standards. The USACE responded immediately after the November 2021 floods to complete emergency repairs to damaged levees. 

Community Partnerships

Successful river management requires partnerships and participation from the larger community. Our River and Flood Division is currently working with a Floodplain Integrated Planning (FLIP) team to update the Lower Nooksack River Comprehensive Flood Hazard Management Plan and integrate flood hazard reduction strategies with the needs of salmon and agriculture. The FLIP team includes representatives from: FCZD and subzone advisory committees, diking districts, the Nooksack Indian Tribe and Lummi Nation, federal, state, and local agency staff, and technical experts. Meaningful change happens when everyone works together.  

Flood Forecasting

Many different government agencies work together to monitor river levels and forecast floods. The FCZD partners with the U.S. Geological Survey (USGS) and the U.S. Department of Agriculture (USDA) to maintain several river gauging stations and Snow Telemetry (SNOTEL) sites. Remote weather stations maintained by the National Resources Conservation Service (NRCS) provide real time weather information. The National Weather Service forecasts river levels and flood events. Our River and Flood Division staff utilize these tools and work with other local jurisdictions and emergency responders when a flood is forecasted to monitor current conditions and initiate emergency response.