Civil & Structural Design
Client: Coastal San Luis RCD, County of San Luis Obispo
In 1959 the lower three miles of the mainstem Arroyo Grande Creek were converted to a trapezoidal flood control channel to reduce flood risk to high value farm land. Sedimentation, vigorous riparian growth and changes in the watershed due to urbanization have altered the flood control channel to the point where it provides very little in the way of flood protection. In addition, environmental regulations that protect sensitive species have limited the ability of the County to perform channel maintenance work. In 2001 a high intensity storm event caused levee failure, resulting in millions of dollars in damage to adjacent farmland and residential properties. In response, the Coastal San Luis Resource Conservation District (RCD) commissioned Waterways staff, in conjunction with SH+G, to evaluate potential alternatives to improve flood protection along this reach of Arroyo Grande Creek. Identified alternatives included levee raising, environmentally appropriate vegetation and sediment management, and erosion control and flood detention projects in the upper watershed to reduce sedimentation in the flood control reach.
Client: Resource Conservation District of Monterey County
Currently undeveloped portions of the North Monterey County High School Campus provide excellent locations for upland and wetland restoration projects that could facilitate educational opportunities. Waterways is supporting Central Coast Wetlands group and the RCD of Monterey County by providing land surveying, preliminary design services, and permit support for proposed nature trails and wetland enhancement projects in support of Red Legged Frog and Santa Cruz Long Toed Salamanders.
Client: West Valley College
Waterways has provided comprehensive planning, grant writing, surveying, design, construction support, and post construction monitoring services for five distinct projects within the West Valley College campus.
- A stream restoration project to restore over 600 linear feet of Vasona Creek within the campus;
- A wetland creation project;
- A 20 acre Riparian Planting Plan along Vasona Creek within the campus, and
- A riparian trail system to provide enhanced access and learning opportunities.
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.
The pond construction at Pilarcitos Quarry included two bentonite-lined ponds within the Nuff Creek watershed, each designed to improve habitat for red-legged frogs. Waterways provided planning services to site the ponds, performed topographic and construction surveying, prepared preliminary and final designs, provided permit support, and supervised the construction effort.
Client: Yamhill Basin Council
Waterways staff prepared the engineering design documents to reactivate a historic secondary channel on Gooseneck Creek and encourage bed aggradation through a bedrock reach. The project is located above the confluence with Mill Creek in Polk County, Oregon. The secondary channel was plugged during gravel mining operations over the last several decades. The effect on the main stem channel has been an increase in flow velocities and energy and subsequent downcutting of the creek to bedrock.
Client: Oregon Parks and Recreation
Waterways Consulting recently completed a restoration plan for Jackson Creek and Netarts Creek for the OPRD at Cape Lookout State Park. The focus of the effort was to evaluate the hydrology, geomorphology, and habitat conditions of Jackson Creek, the principle stream that flows through Cape Lookout. Approximately 60 years ago, a portion of Jackson Creek was diverted to Netarts Bay to increase freshwater flows into Netarts Bay with the hope of improving the commercial oyster beds. Impacts associated with the diversion and associated flow split were addressed in the restoration plan as well as opportunities for enhancement of the Jackson Creek mainstem downstream of the diversion site.
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.
Waterways is teaming with CMAG Geotechnical Engineers to assist the Resource Conservation District of Santa Cruz County and USFWS with the siting, design, and installation of multiple ponds to enhance and expand habitat for the endangered Santa Cruz Long Toed Salamander.
Client: City of Watsonville
Under Phase 1, Waterways staff designed a seven mile network of pedestrian and bicycle trails along the Watsonville Sloughs System, within the City of Watsonville. Our scope included the preparation of a Trails Master Plan, identification of opportunities and constraints, engineering feasibility assessment, hydraulic modeling, final plans and specifications, permit support, and construction monitoring. The trail designs were implemented successfully, creating public access footpaths and bicycle trails with trail segments that also provide Americans with Disabilities Act-compliant access. Design challenges included multiple slough crossings (boardwalks), retaining walls, and bridges constructed on peat soils within a complex hydrologic regime. Design of each trail segment offered opportunities for ecological restoration, including removal of exotic vegetation and re-vegetation with native communities.
For phase 2, Waterways created a Master Plan for over 25 additional miles of trails within and adjacent to the City of Watsonville. Waterways is currently preparing 100% designs for portions of the Phase 2 trails system.
Client: Resource Conservation District of Santa Cruz County
Waterways Consulting has provided planning, design, and construction implementation support (e.g., staking, field modifications, and supervision) for the installation of 3 ponds located on the Watsonville Slough Farm property, owned by the Land Trust of Santa Cruz County. The ponds were created either as a stormwater or sediment control facility or for habitat enhancement.
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
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:City of Watsonville
The CARE project includes an ADA compliant pedestrian and bicycle trail providing community access to through a riparian corridor along the Pajaro River, near its outlet to the Pacific. The trail was designed with a surface that could be easily maintained following periodic inundation and fine sediment deposition within the floodplain through which it traverses. The trail provides an outlet to a scenic overlook on the Pajaro River, as well as to a boat launching ramp.
Client: Clean Water Services (CWS), Oregon Department of State Lands (DSL)
Waterways assisted Clean Water Services and Department of State Lands in the planning and design of a 20 acre mitigation bank in the Tualatin River Watershed to provide wetland, temperature, and salmon credits. In addition to providing purchasable credits, the project simultaneously tested a function-based accounting system developed by the Willamette Partnership’s Counting on the Environment program (http://www.willamettepartnership.org). This program was developed with the help of public, private, and non-profit stakeholders to create a shared accounting system for quantifying impacts and benefits to ecosystem services for application to ecosystem markets. The Partnership has completed a test version for water temperature, wetlands, salmonid habitat, and upland prairie that was applied to pilot projects. Half Mile Lane was one of the pilot projects that tested three of these services, and was the first pilot site that resulted in real-world transactions. The project tested not only the ecosystem credit calculator, but also the sequence of developing, selling and buying ecosystem credits.
Client: Resource Conservation District of Santa Cruz County
The Resource Conservation District of Santa Cruz County (RCD) retained Waterways to prepare a sediment source analysis and action plan for the recently acquired Geyer Quarry property. The Land Trust of Santa Cruz County purchased the property in 2008 to provide protection to a portion of the unique and delicate Sandhill ecosystem that extends from the Bonny Doon through the Scotts Valley area of the Santa Cruz Mountains. Mining activity, road construction, logging, and off‐highway vehicle (OHV) use have exposed steep, denuded hillslopes in many locations throughout the parcel. These eroded areas deliver excessive volumes of sediment to the San Lorenzo River and its key tributaries (in this case Bean Creek and Zayante Creek). The large sediment inputs to the tributary channels negatively impact salmonid habitat.
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: Resource Conservation District of Santa Cruz County
Waterways provided geomorphic assessment, land surveying, and engineering design services for ecological enhancements to a degraded reach of Sycamore Creek, at the confluence with Uvas Creek. The design included recontouring channel banks and the creation of inset floodplain benches to reduce erosion. Native vegetation was established on graded areas. Hydraulic control structures installed at the project included periodic boulder weirs and stilling pools for energy dissipation and a sheetpile cutoff at the project terminus. The detailed grading plan allowed for the retention of mature riparian trees within the project footprint.
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: 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.
Waterways staff assisted the NRCS in the fall of 2015 with construction phase services for the implementation of agricultural pond repairs in Alameda County. Our role included construction staking and as-built mapping, construction observation and reporting, and field engineering services.