Lower Clear Creek Floodway Rehabilitation

Westside Region

Lower Clear Creek Floodway Rehabilitation

  • Location: Clear Creek near Redding, Shasta County
  • Project Sponsor: Western Shasta RCD
  • Time Frame: 1998–2009
  • Funding: Western Shasta RCD grants totaling $15,299,000 from Reclamation, BLM, USFWS, CALFED, USFS, Shasta County, EPA, NFWF, NRCS, Cal Fire, DOC, NPS, California Resources Agency. BLM $7,000,000 in land purchases along the floodway
  • Project Objectives:
    • restore natural form and function of the stream and floodplain
    • increase quantity and quality of anadromous fish habitat
    • increase quantity and quality of riparian habitat
    • establish a corridor of public access and recreation use

In fall 2002, more than 15,000 Chinook salmon migrated out of the Sacramento River and into the shallow waters and gravel beds of Lower Clear Creek. By contrast, between 1967 and 1991, the average fall-run salmon population in Clear Creek was fewer than 1,700 fish. This remarkable upswing in the fish population was the product of a dramatic transformation from a severely degraded waterway to a healthy and functional stream ecosystem, accomplished through completion of a project called the Lower Clear Creek Floodway Rehabilitation Project.

Clear Creek originates in the Trinity Mountains west of Redding, flows through Whiskeytown Reservoir and then 16.5 miles to the Sacramento River. A series of landscape perturbations (gold mining, gravel extraction, and dam building) altered the channel morphology of Lower Clear Creek between Whiskeytown Dam and the Sacramento River drastically. Problems included loss of gravel bars, disconnected floodplain, channel scouring and entrenchment, degraded riparian vegetation, and fish stranding in isolated dredger ponds. Beginning in 1995, state and federal agencies together with the Western Shasta RCD and the Clear Creek CRM began site assessment and the development of a restoration plan to create a new bankfull channel, functional floodplain, gravel supply, and native riparian vegetation. Work began in 1998 and was completed over a series of phases that involved reduction of salmon stranding, floodplain creation, instream channel improvements, and gravel supply augmentation.

  • Phase 1 (1998) constructed a large gravel berm (27,000 cu.yds) to isolate salmon from gravel pit stranding.
  • Phase 2 (1999) filled gravel extraction pits with dredger tailing piles along with 70 acres of riparian planting.
  • Phase 3A (2002) reconstructed a primary channel and restored floodplain surfaces and riparian vegetation.
  • Phase 3B (2006 restored a 0.8 mile section of the creek and revegetated 20 acres of new floodplain.

The history of gold mining had left a complex of large pits and ponds that frequently would capture adult and juvenile salmon when streamflows rapidly dropped. These were filled and the area was leveled to an elevation more likely to receive floodwater under the controlled releases from Whiskeytown Dam. More than 105 acres of floodplain were reconstructed, and 78 acres of that were replanted with native riparian vegetation. The instream channel work involved converting a barren bedrock channel to a cobble-bedded stream with natural gravel bars, pools, and riffles. The Western Shasta RCD installed large trees and root wads that protect the banks of the newly constructed stream channel and provide shelter for juvenile fish. Other aspects of the Lower Clear

Creek Restoration and Management Plan included:

  • augmentation of 151,219 tons of gravel to reverse the loss of salmon and steelhead spawning habitat from 1998 to 2009;
  • a revised schedule of controlled flow releases from Whiskeytown Dam to benefit migrating and spawning fish;
  • removal of the 15-foot-high McCormick-Seltzer Dam built in 1903 to divert irrigation water, creating a barrier to fish spawning and rearing habitat in the upper 10 miles of Clear Creek; and
  • implementation of projects in the upland areas to reduce erosion, prevent catastrophic wildfire, and improve watershed conditions overall.

All aspects of the Clear Creek project are being carefully monitored by the RCD, private consultants, and state and federal agencies to evaluate project performance. More than 10 years of data collection have shown a dramatic increase in fall- and spring-run salmon, a recovery of the riparian plant community, a marked increase in song bird populations, and a generally properly functioning stream channel and floodplain. The land acquisitions and public greenway established by BLM’s Redding Resource Area Office have provided a several-mile-long stream corridor that is now available for public use and enjoyment.