SERVICES

• Time Series Modeling
• Analysis of Ramping Effects on Fish Habitat
• Habitat Mapping and Statistical Analysis
• Acoustic Doppler Current Profiles
• Application of the Delphi Method in Instream Flow Negotiations
• Development of Mitigation Plans
• Agency Consultation
• Resource Management Negotiation

DTA offers a range of methodologies to complete instream flow research:

• 1D (PHABSIM) and 2D Modeling
• Small Stream Instream Flow Assessments
• DELPHI Instream Flow Assessment Method
• Time Series (multi-flow, habitat/discharge modeling)
• Analysis of Ramping Effects on Fish Habitat (dual-flow and 2-flow peaking analyses)
• Habitat mapping and statistical analyses
• Aerial videography of stream corridors and habitat
• Acoustic Doppler Profiles
• Development of mitigation plans
• Agency Consultation

Advanced hydraulic profiling including hydrodynamic and bathymetric surveys:

• Mapping velocities and bed profiles around structures and intake screens with an Acoustic Doppler
• 3D velocity and bathymetric charts
• Use of accurate navigation equipment and GPS to pinpoint survey locations
• Proprietary programs that interface with the Acoustic Doppler for quick and accurate data analysis
• Results accurately displayed in a GIS map database

Our research staff also offers services addressing water resource issues:

• Stream, groundwater and precipitation gaging
• Water budget analysis
• Historic and current hydrologic analyses and time series modeling
• Temperature and sediment monitoring
• Strategic watershed planning

Project Examples

Lower Skagit River Instream Flow Studies, Skagit County PUD no. 1 and City of Anacortes, Washington.

DTA staff conducted an instream flow study of the lower Skagit River focusing on the habitat, hydrologic and instream flow needs of anadromous salmonids Read More...

Cedar River Fisheries and Instream Flow Study

The Cedar River is the source of 70 percent of Seattle’s municipal and industrial water supply.  Below the City’s diversion, the river supports a large spawning population of sockeye salmon and a valued run of steelhead trout. Read More...