stream and
Watershed Health
River Restoration
WWE has planned, designed, and permitted numerous river and stream restoration projects since the 1960s. WWE’s techniques and approach are focused on resilient, sustainable designs that are environmentally friendly. We take pride in developing process-based river restoration designs that mimic nature in terms of resilience, functionality, maintenance, and benefits. Our projects have ranged from small, high-gradient creeks in the mountains to larger systems in the plains. Our designs provide positive ecological uplift along riverine corridors and maximize the ecological services provided by the watershed.
Diversion Structure Design
WWE has designed diversion structures that balance the needs of humans and the environment for a variety of clients in an array of locations. Many different diversion approaches have been developed at WWE ranging from simple side-channel diversions to channel-spanning structures and infiltration galleries. Our diversion structures are designed to limit impacts to the surrounding environment, allow fish passage, and provide sediment transport. The designs employed at WWE are constructed from a combination of materials to provide hardline stability where needed and incorporate natural channel techniques in the forms of cross vanes, wings, and arms. Our engineers are experts at defining and addressing challenging design parameters for surface diversion structures in cold, high-altitude alpine climates.
Fish Passage
WWE has developed fish passage designs for myriad riverine systems. Our designs provide passage for capable fish such as trout and other game fish, but also for less agile native fish such as suckers and chubs. These fish passage designs are constructed using natural channel design techniques where possible and then evaluated using two-dimensional hydraulic models to verify fish passage criteria are met. Our fish passage designs have also included removable fish barriers to allow our scientific partners to complete biodiversity studies. Our fish passages designs can be included in original construction of diversions or retrofitted to provide fish passage at existing structures.
Fish Habitat Improvement
Improving fish habitat is an important goal of WWE’s for all river restoration projects. Creating and enhancing fish habitat in streams and lakes can add significant recreational value to a community. These projects are often complex with multiple water supply, water quality, habitat quality, and permitting considerations. Fish habitat improvements can take place above or below the water surface. Fish habitat improvement also includes ensuring the proper nutrients, temperature, flow, and overall environment are optimal for the fish species of concern. Fish habitat can be enhanced through the development of pools and the creation of natural cover in the form of strategically-placed logs and rocks, or stabilized undercut banks. Fish habitat is not only a place of refuge for fish but also a source of food. WWE utilizes our biological and ecological consultants to develop fish habitat that is ideal for the species of interest.
Floodplain Analysis, Permitting, and Mitigation
Most riverine work will require floodplain permitting through the Federal Emergency Management Agency (FEMA). WWE is experienced in helping clients obtain floodplain permits necessary to complete a given project, such as Conditional Letters of Map Revision (CLOMRs), Letters of Map Revision (LOMRs), Flood Hazard Area Delineations (FHADs), and No-Rise certifications. Hydrologic modeling of floodplains can utilize GIS, which leads to efficiencies in the project design. Our team of engineers is also adept at developing grant-eligible flood hazard mitigation projects through FEMA.
Hydrological Evaluation
WWE is skilled in the utilization of stream gages, rainfall-runoff models, bankfull indicators, and high-water marks to understand the various hydrological regimes of a given watershed. WWE uses hydrological data to develop typical channel sections and establish channel velocities to avoid degradation to the channel, its ecology, and/or its biology. Hydrological information can also be used as part of floodplain mapping updates. WWE can also utilize reference reach information to back-calculate hydrology from geomorphic indices to help design stable channel reaches.
Hydraulic Evaluation
WWE utilizes cutting-edge hydraulic models to fully understand the dynamic elements of a riverine system. Standard modeling platforms such as HEC-RAS, HEC-RAS 2D, SRH 2D, and Flo2D are used to develop designs that are stable and resilient. The hydraulic models are not only used for design but also permitting. These hydraulic models provide useful visualizations that can help illustrate intricate flow variations across a channel. The modeling platforms used provide a wealth of information for other riverine design parameters such as shear stress, incipient motion, and fluvial hazards.
Geomorphology Studies
WWE is experienced in applying geomorphic principles and tools to understand fluvial and hillslope systems. WWE leverages field and desktop methods, such as grain-size distribution and bedform surveys, historical aerial image analysis, and sediment transport modeling, to deliver solutions that align with natural landscape form and function. Examples of projects with a strong focus on geomorphology include characterizing debris flow deposits and modeling debris flows to inform proposed development, assessing bank stability and predicting rates of erosion in a meandering river system, and designing resilient channels in incised, ephemeral areas. Our geomorphic capabilities complement our hydrologic and hydraulic skillset and provide a more complete understanding of the system of interest, whether on a single reach of river or on a full-watershed scale.
Environmental Flow Evaluations
WWE has the capability to evaluate flow demands of a healthy watershed within the banks as well along riparian areas and floodplain benches. WWE uses number of hydraulic modeling tools including R2Cross to better understand the biological needs of riverine systems. The modeling enables us to understand how much water a system needs as well as assess how the system meets the instream flow requirements of non-profits and/or the Colorado Water Conservation Board. This information can be used to understand the impacts of no-diversion agreements and to determine the environmental flows needed to provide ecological benefits beyond the top of the bank for high-value sensitive plant species. WWE also has experts in water rights to support these endeavors.
Wetland and Sensitive Species Permitting
WWE has successfully obtained Section 404 permits for projects varying in size and complexity from small-scale wetland assessments to large-scale projects requiring individual 404 permits and compensatory mitigation. Our aquatic resources scientists also have expertise in sensitive species permitting. They communicate complex regulatory concepts to stakeholders in an easy-to-understand manner, helping clients avoid procedural missteps, project delays, and unexpected costs while obtaining the necessary authorization from the U.S. Army Corps of Engineers.
CONTACTS
Scott Schreiber, P.E., CFM
Andrew Earles, Ph.D., P.E., D.WRE, CPESC