Watershed/ Geomorphic Assessments
Client: Tualatin River Watershed Council (TRWC)
In March of 2003 the TRWC completed work on the Lower Gales Creek Habitat Enhancement Plan. Gales Creek is a major tributary to the Tualatin River in Washington County, Oregon. The Enhancement Plan identified potential restoration projects designed to improve habitat conditions for steelhead and other salmonids. To evaluate the feasibility of implementing potential channel, floodplain, and habitat enhancement projects, TRWC retained the services of Waterways staff to conduct a comprehensive geomorphic assessment of the planning reach and prioritize potential restoration options. The geomorphic assessment and project feasibility study was completed in 2005. Following completion of the study, Waterways has continued to work with the TRWC by preparing construction documents for site specific projects aimed at enhancing channel and floodplain function, improving in-stream and off-channel aquatic and wetland habitat, and restoring riparian areas. Waterways and TRWC has worked closely with landowners and other stakeholders to achieve the identified goals.
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: Scappoose Bay Watershed Council
In 2000, the Scappoose Bay Watershed Council (SBWC) completed a watershed assessment for the streams that enter Scappoose Bay. The watershed assessment identified several areas of concern affecting watershed and ecosystem health. Of particular concern was the potential impact that incision has on channel and floodplain interaction and the ability of the stream to support and maintain good aquatic habitat. A five mile stretch of South Scappoose Creek that flows through the City of Scappoose was determined to be a high priority reach for further assessment. It was identified as a priority for further assessment due to local concerns about erosion and flooding and the opportunities to enhance conditions for salmon and other organisms.
Client: American Rivers, Inc.
American Rivers performed an assessment of Alpine Meadows in the Carson River watershed, and identified Faith Valley as its highest priority meadow restoration due to its impairments and its popularity with recreational users for fishing, hiking, and camping. American Rivers hired Waterways to complete a baseline conditions assessment and develop designs for habitat improvement. The baseline assessment included topographic survey, modeling, geomorphic mapping, botanical and other assessments. The assessment determined that the primary cause of impairment in Faith Valley is channel incision and associated detrimental impacts, including bank erosion, lowered groundwater table, and degradation of meadow plant assemblages.
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: Town of Truckee
Over the past 150 years, Trout Creek, a tributary to the Truckee River, has been impacted by development of the downtown, the railroad, and other land uses. These impacts have resulted in channelization and realignmentof Trout Creek, upsetting natural channel processes such as bed load movement, habitat creation, hydrology, and wildlife corridors through loss of riparian habitat. Despite past efforts to “control” Trout Creek, flooding has remained a significant problem. In addition, the biological and aesthetic value of the channel was degraded.
Client: County of San Luis Obispo
Waterways was contracted by the County of San Luis Obispo Public Works Department (Utilities Division) to provide assessment, design and construction observation services for the improvement of fish passage conditions and the protection of a waterline in Arroyo Grande Creek at the Rodriguez Bridge crossing. Our work also included preparation of a design report and response to comments from NMFS fish passage engineers.
Just upstream of Rodriguez Bridge there was an exposed concrete encased water supply line within the bed of Arroyo Grande. Channel scour on the downstream side of the encasement had nearly undermined the encasement, potentially leading to structural failure of the pipeline, and leaving a 3 foot hydraulic drop that created a partial barrier to fish passage.
The designs for fish passage improvements and pipeline included installation of a roughened channel. The channel was reconstructed for approximately 250 feet, using imported rock to provide a smooth transition in the stream profile and hydraulic conditions conducive to fish passage. Two pools and a woody debris structure were incorporated into the project to provide resting and rearing habitat. Additionally, boulder weirs were installed to maintain pool scour and grade control through the project area.
Steelhead were not found in the project reach during pre-construction field surveys. However, steelhead were observed both upstream and downstream of Rodriguez Bridge, and near the installed woody debris structure during post-construction monitoring. The project has greatly improved fish passage conditions and is meeting established success criteria.
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: Coastal San Luis Resource Conservation District
NOAA Fisheries Recovery Plan for steelhead populations lists Pismo Creek as a high priority system for the recovery of the South Central California Coast Steelhead ESU. Limiting factors to their continued survival in the Pismo Creek Watershed are water withdrawals and fish passage barriers. One of the most significant fish passage barriers in the lower portion of the system is a Union Pacific Railroad Crossing that blocks all life stages of steelhead under all flow conditions. Incision downstream of the concrete culvert railroad crossing has resulted in a 12 foot drop over the concrete structure along with a broad concrete apron through the culvert itself that creates shallow flow under most discharges. A series of Denil fish ladders were installed at the site in the 1980’s but has proven to be ineffective at providing fish passage and requires constant maintenance from debris and bedload.
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: 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: Granite Construction Company
Waterways staff assisted Granite Construction Company with planning, designing, and permitting an off-channel gravel extraction project on the Kunzler Ranch property, located in Ukiah Valley at the confluence of Ackerman Creek and the Russian River. Waterways conducted hydrologic, hydraulic, and geomorphic analyses to assess flooding impacts, habitat development potential, and channel stability at the proposed project site during project-life and reclamation phases.
Clean Water Service (CWS) is tasked with managing stormwater in portions of Washington County, OR that fall within the Urban Growth Boundary with the goal of protecting waterways and natural resources within stream and wetland corridors. When a new development is proposed, CWS works with the developer to meet regulatory requirements associated with increased runoff from impervious surfaces with the goal of maintaining discharges of stormwater to pre-development conditions. Traditionally, meeting these requirements consists of designing and constructing large, regional stormwater management facilities in upland areas adjacent to the new developments.
Client: Land Conservancy of San Luis Obispo County
The Land Conservancy of San Luis Obispo County has identified a long-term plan to protect water supply and watershed lands on the Nacimiento River, upstream of Nacimiento Reservoir, through a strategy of conservation easements and direct land acquisition. Through this process, the landowner of the 8,300 acre Attiyeh Ranch, located just upstream of Nacimiento Reservoir, approached The Land Conservancy for assistance in developing a plan to protect his property, in perpetuity, for watershed protection and habitat conservation.
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: Truckee River Watershed Council, U.S. Forest Service
Alpine meadow systems within the central Sierra Nevada have been greatly impacted by past land use practices. One important meadow system that is somewhat intact is Perazzo Meadows, located in the headwaters of the Little Truckee River Watershed. Waterways provided assistance to the Truckee River Watershed Council and the U.S. Forest Service in an evaluation and characterization of the Perazzo Meadow complex and the surrounding watershed. The assessment consisted of a geomorphically-based assessment of the meadow complex. The geomorphic and hydrologic characterization of the meadow system was necessary to provide a framework for planning and design of a comprehensive restoration effort to restore floodplain connectivity and meadow function. It has been well documented that “process based” restoration projects that consider the geomorphic and hydrologic setting of the watershed have a higher likelihood of being successful. Gaining an understanding of these processes allows for development of feasible restoration approaches that are founded in the physical processes which operate in these alpine meadow systems.
Client: City of St. Helena
Waterways staff worked with the City of St. Helena and a team of consultants to design, permit, and construct a multi-objective flood control and habitat restoration project, The project, constructed in 2009 and 2010, provides 100-year flood protection for residential properties along the Napa River, restores important floodplain and aquatic habitat, and improves public access. Specific elements of the project include a geomorphically-based floodplain terrace and associated shoreline restoration involving removal of an existing gabion and rip-rap bank protection structures and replacement with a natural point bar shoreline configuration, bioengineered bank stabilization structures, FEMA certified levee setbacks and floodwall construction, relocation of homes from the floodplain, and approximately 2,500 ft of pedestrian trails with interpretive signage. Design elements were incorporated into project to enhance habitat for a variety of species including salmon and steelhead, river otter, California red-legged frog, and freshwater shrimp.
Client: Coastal Watershed Council
The primary objective of this project was to develop a watershed assessment and enhancement plan for the Aptos Creek Watershed with a focus on restoration and enhancement of salmonids spawning and rearing habitat. Aptos Creek is a small coastal drainage located in southern Santa Cruz County. A variety of land uses occur within the watershed including urban, rural residential, orchards, timber harvests, and recreation. A large portion of land is protected within the Forest of Nisene Marks, which is part of the California State Park System.
Client: Clackamas County, Water Environment Services
Clackamas County Water Environment Services (WES) is one of the agencies responsible for wastewater and stormwater management in the greater Portland metro area. To better understand the effects of management activities on watershed health and the status of aquatic resources in the district, WES contracted with Waterways to develop monitoring methods and carry out monitoring of aquatic resource and physical habitat conditions in its management region, which consists of small and medium sized tributaries in the lower Willamette, Clackamas, and Tualatin Rivers, in northern Clackamas County, OR. In close cooperation with WES, Waterways led the development of geomorphic monitoring approaches, site selection, establishment of monumented cross sections and initial monitoring of 25 to 30 stream reaches in 2009. Each monitoring event includes long profile and cross section surveys, bulk bed material sampling, pebble counts, large wood inventory, measurements of pool size and frequency, documentation of active bank erosion, and general geomorphic observations. These data are complimented with macroinvertebrate population analysis of the same reaches by Mike Cole (Cole Ecological), a regional expert in stream macroinvertebrates. WES retained Waterways to lead monitoring events in 2009, 2011, 2014, and 2017.
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: United States Forest Service
The Cookhouse Meadow Restoration Project replaced approximately 1600 linear feet of stream that was incised by 4-6 feet within a meadow setting. The new channel provided a more natural channel morphology, flood regime, and soil moisture regime throughout the meadow. In turn, water quality, vegetation composition, and fish and wildlife habitat was improved. The project used stacked sod, salvaged from distributed areas throughout the adjacent meadow, to construct stable banks that will allow for natural channel evolution and adjustment.
Client: Sierra Nevada Alliance
The California Unified Watershed Assessment identified the Upper Carson River as a Category I priority watershed for water quality improvement. The Sierra Nevada Alliance, on behalf of the Alpine Watershed Group, responded by initiating the preparation of a Stream Corridor Condition Assessment for the Upper Carson River Watershed with funding from the California State Water Resources Control Board. The assessment included a fluvial geomorphic assessment, a survey of conditions in the riparian and floodplain zone, a list of prioritized restoration projects, and a recommended list of management measures. Waterways staff joined the assessment team as the project team hydrologists and geomorphologists and as the primary project team members evaluating riparian health and providing restoration project recommendations. The assessment included approximately 66 miles of stream channel within the West Fork Carson River, East Fork Carson River, Wolf Creek, and Markleeville/Hot Springs Creek.
Client: American Rivers, Inc. & Placer County Resource Conservation District
Waterways was selected to develop and analyze alternatives for ecological restoration of the Hope Valley Meadow on the West Fork Carson River, with a primary goal of enhancing the full range of ecosystem services this highly visible and well-known meadow provides. The project area encompasses approximately 400 acres of the meadow within Upper Hope Valley, just east of Blue Lakes Road, Alpine County.