Hydrologic & Hydraulic Modeling, Analysis, & Gauging
Client: RCD of Santa Cruz
A watershed assessment prepared for the East Branch of Soquel Creek identified limiting factors for steelhead and coho production which included high sediment loads, lack of pools, low summer base flows, and high water temperatures. In 2013, the Resource Conservation District of Santa Cruz County contracted with Waterways to prepare a feasibility analysis and engineered designs for biomechanical bank stabilization of a large eroding cutbank and the creation of habitat enhancements along approximately 1,500 feet channel banks that were covered with unvegetated riprap, resulting in lack of habitat complexity or riparian cover.
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: Cascade Environmental Group
Waterways has teamed with Cascade Environmental Group to develop, implement, and monitor a restoration plan for approximately 30 acres of riparian and bottomland forest along the Willamette River in the city of Gladstone. The site encompasses a short, perennial tributary known as Rinearson Creek that is periodically backwatered from the Willamette River and provides rearing and off-channel refugia for a variety of species and life stages of salmon.
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: South Coast Habitat Restoration
South Coast Habitat Restoration contracted with Waterways to provide design services for the improvement of fish passage conditions at Widdoes Crossing, a private road crossing on Gobernador Creek. Fish passage conditions at the site were severely impacted by incision of the streambed below a concrete and boulder ford which created an 8 foot hydraulic drop.
Client: Santa Cruz County Resource Conservation District
Waterways staff prepared engineering plans and specifications for stabilization of approximately 100 linear feet of stream bank on Corralitos Creek in Santa Cruz County, California. The bioengineered bank stabilization included fabric encapsulated soil lifts contained within a log revetment structure. Logs were selectively harvested by thinning redwoods from an adjacent grove, thus reducing the cost and environmental impact of the project. Our staff performed construction supervision to ensure successful implementation. Revegetation has been successful and the bank now provides quality habitat in addition to controlling bank erosion and sedimentation in the creek.
Client: U.S. Fish and Wildlife Service
The Seestrom Tidelands Restoration project will construct approximately four miles of tidal floodplain channels and restore fish access and tidal flows within a 300-acre working pasture property in the lower reach of the Coquille River, Oregon. Conversion to pastureland at the site began in the early 1900s with the clearing of native forest, construction of levees and linear drainage ditches, and installation of tidegates, which are currently in disrepair, preventing active tidal flows and fish movement.
Client: USFS- Lake Tahoe Basin Management Unit
Waterways, in coordination with the USFS Lake Tahoe Basin Management Unit (LTBMU) and Swanson Hydrology, has developed designs to restore the mainstem and tributaries of Cold Creek in the High Meadow Complex (HMC) near South Lake Tahoe, California. The basic restoration objective is to increase soil moisture within approximately 70 acres of meadow area by modifying the morphology and hydrology of the streams in a manner consistent with natural geomorphic processes. Work involves re-constructing approximately 8,700 linear feet of channel and raising the elevation of the streambeds by 2 to 4 feet. The project will significantly increase the diversity and density of meadow wetland vegetation species and shift some areas from seasonally dry and sparse mesic meadows to wet meadow conditions.
The project’s three-year construction plan was completed in 2012, with Waterways providing on-site construction observation.
Client: California Trout, Inc.
Lower Hat Creek is an important coldwater fishery and is a designated Wild Trout Fishery by the California Department of Fish and Wildlife. Decades of cattle grazing, the introduction of muskrats, and over fishing caused the degradation of riparian and aquatic habitat along lower Hat Creek. Waterways, in collaboration with Streeter Group and California Trout, Inc., completed designs to restore a reach of Hat Creek. The restoration measures included installing a 160’-long pedestrian bridge and trail, and relocating the parking facilities that improve angler access and reduce habitat disturbance.
Client: Coastal San Luis Resource Conservation District
Channel and riparian conditions along Tally Ho Creek within the project area have changed significantly over the last several hundred years. Pressure to utilize flat valley bottoms for agriculture and, later, suburban development, resulted in removal of much of the riparian vegetation, filling of wetlands, road building, and straightening and deepening of Tally Ho Creek. Cleared portions of the valley bottom now consist of single-family homes and Tally Ho Road. Tally Ho Creek has been confined to the eastern edge of the valley floor.
Client: US Forest Service
Waterways staff led an interdisciplinary team to assess existing conditions within the Blackwood Creek Watershed, and then prepare detailed engineering plans and specifications for recommended projects. Blackwood Creek is a major tributary to Lake Tahoe, drains a mix of steep volcanic and granitic terrain, has a high bedload transport rate, and was historically impacted by grazing, logging, and instream gravel mining. Key impacts identified during the study were excessive bank erosion and channel widening associated with channel incision and loss of floodplain connectivity and the presence of several fish passage barriers. To restore the physical processes that sustain channel morphology and biological function, an aggressive, long-term restoration strategy was proposed. To date, four distinct restoration projects have been designed and implemented: