Hamilton City: Community Commitment to Reducing Flood Risk

The small Sacramento River community of Hamilton City has long faced flood risk when rivers run high. Surrounding agricultural areas face additional inundation when water is released from the Shasta Reservoir to alleviate flood risk during the rainy season. By taking multiple policy objectives into account – including improving habitat for threatened and endangered species – the local community worked with The Nature Conservancy and state and federal agencies to develop a flood control solution with multiple benefits.

Hamilton City, located about nine miles west of Chico along the Sacramento River, has faced many floods. The town has been evacuated six times in the last 30 years: in 1983, 1986, twice in 1995, 1997, and 1998.

The surrounding agricultural community faces challenges associated with Hamilton City’s propensity to flood. About 3 miles southeast of Hamilton City, farmland is frequently flooded on what the growers call blue sky days – even when there is no rain in sight flood management decisions (i.e., release of flood storage from Shasta Dam) may still result in flooded fields and damaged crops.

After the 1998 flood, area residents determined that there had to be a better way forward. They raised money locally from both taxes and donations and partnered with The Nature Conservancy and state and federal agencies to replace a private levee, known as the J levee, which provides only a 66 percent chance of protecting against a 10-year flood event, with a new set-back levee.

This “set back” increases the flood safety in Hamilton City and adds 1,361 acres of riverside habitat which will benefit more than 50 threatened species in the region. The new levee will have 90% confidence of passing a 75-year flood event. Once the Army Corps of Engineers took the benefits of both flood protection and environmental restoration into account, it became clear that the project “pencils out” and is worthy of federal funding.

The project was awarded nearly $13 million in the federal FY14 budget to begin construction.

Multiple Benefits Delivered

  • Enhancing public safety.
  • Reducing costly flood damage.
  • Protecting fish and wildlife.
  • Protecting working farms and ranches.
  • Providing recreational opportunities.
  • Improving water quality.
  • Contributing to water supply reliability.
  • Preparing for extreme weather events and climate change.
  • Reducing costs by moving beyond mitigation.

Project Partners

  • California Department of Water Resources
  • Glenn County
  • The Nature Conservancy
  • Reclamation District 2140
  • U.S. Army Corps of Engineers
  • U.S. Fish & Wildlife Service