Fish Passage & Screening
Client: Wasco County Soil and Water Conservation District
Mill Creek is a moderately-sized tributary to the Columbia River that originates on the eastern slope of Mt. Hood and flows northeast through the City of The Dalles, Oregon. Urbanization along the lower two miles of Mills Creek in the City of The Dalles resulted in the simplification of the aquatic and riparian habitats. In 2011, The Dalles Watershed Council (DWC) commissioned an evaluation of the urbanized reach to assess land use impacts and identify opportunities for habitat restoration. Following the initial assessment, a preliminary engineering design was developed for the Honald/Buyers property. The preliminary design included excavation and connection of a historic side channel that had been partially filled, utilization of an existing side channel as a backwater alcove, installation of a precast spanning bridge across the reconnected side channel, and installation of large wood structures along the channels and floodplain to increase roughness and improve habitat conditions.
Client: Sempervirons Fund and Peninsula Open Space Trust
Mill Creek is the largest tributary of San Vicente Creek, in Santa Cruz County, an important stream for steelhead and coho salmon on the central California coast. Mill Creek drains a small, steep watershed containing a localized area of granitic rocks within the highly erosive marine sediments that dominate the Coast Range. Because of this, Mill Creek is an important source of resistant spawning gravel, which is limiting for fish in many watersheds in the central Coast Range. Within the recently-acquired San Vicente Redwoods Preserve, two dams on lower Mill Creek impound gravel and prevent fish passage.
Client: Monument Soil and Water Conservation District
Cottonwood Creek is a major tributary to the North Fork John Day River and has been identified as critical habitat for Middle Columbia River steelhead. The lower four miles of the creek enters a broad valley, providing opportunities for agriculture that relies on the water of Cottonwood Creek for production. There are currently 12 diversion sites along lower Cottonwood Creek, referred to as points of diversion (POD’s). Many of these diversions result in fish passage barriers during the low flow season. The Monument Soil and Water Conservation district requested Waterways assistance in the assessment of channel stability and fish passage for all 12 PODs and designs for three of the known fish passage barriers.
Client: Latimer Environmental
The Hillsboro Landfill is a construction-demolition waste landfill situated on 400 acres south of Hillsboro, Oregon between SE Minter Bridge Road and the Tualatin River. With the landfill operations located at the northeast end of the property, the south and west sides of the property contain wetland mitigation sites adjacent to the Tualatin River. Waterways was retained to design an outfall from the constructed wetlands located at the south end of the property that provides a geomorphically stable discharge into the Tualatin River.
Client: South Coast Habitat Restoration
Waterways was retained by South Coast Habitat Restoration to prepare designs for improving fish passage at five barriers along Gaviota Creek. The sites are located north of Gaviota and directly adjacent to Highway 101. Each barrier is composed of a concrete grade control structure, originally installed to keep the creek from undermining Highway 101. Design concepts range from structural modification of individual weirs to complete removal and channel realignment.
Client: San Lorenzo Valley Water District
Waterways is assisting the San Lorenzo Valley Water District by leading the design team on the Fall Creek fish ladder and diversion screening project. The project involves retrofit of an existing fish ladder and diversion intake structure to comply with current DFW and NOAA fish passage and screening standards. The design lowers existing intake screens and weirs while also adding two additional weirs downstream of the existing ladder to reduce individual jump heights. Phase one was constructed in 2014 and phase two is planned for the summer of 2021.
Client: Tualatin River Watershed Council
Waterways staff prepared engineering designs and specifications to improve passage for steelhead and cutthroat trout on a headwater tributary to the Tualatin River in Washington County, OR. The site consisted of a seasonal flashboard dam. Downstream of the flashboard dam the channel had incised 3-feet creating a fish passage barrier under most flow conditions. The design consisted of a series of five rock weirs to build the bed up downstream of the structure and provide fish passage under all flow conditions by creating a backwater condition at the dam. Waterways assisted the Tualatin River Watershed Council (TRWC) with the permitting and construction supervision. The project was constructed in Summer 2008.
Client: South Coast Habitat Restoration
Waterways provided design and construction support services to South Coast Habitat Restoration to improve fish passage conditions and vehicular access at a private bridge that crosses Carpinteria Creek. The project site had a concrete-lined channel with drop structures that impeded the upstream migration of salmonids and an undersized bridge that could be overtopped during flood events. Site improvements included removing the concrete-lined channel, recontouring the banks, and revegetating the riparian area.