Wildland Hydrology, Inc.
Dave Rosgen, P.H., Ph.D., Wildland Hydrology, Ft. Collins, CO
Workshop 1: Watershed Assessment for River Stability and Sediment Supply (WARSSS)
This workshop is designed for hydrologists, engineers, fisheries biologists, range management specialists, water resource planners and other specialists involved in water resource management and research, aquatic habitat assessment and improvement, river and water quality determination, cumulative impact assessment, TMDL’s, evaluation of riparian ecosystems and watershed analysis. Individuals working with urban, agricultural and wildland watersheds also attend these courses.
WARSSS is a methodology designed for field practitioners to quantitatively determine cumulative watershed impacts affecting sediment yield leading to river impairment. WARSSS identifies specific processes related to individual land uses by location to quantify hillslope, hydrology and channel processes potentially contributing disproportionate sediment supply. The method involves predicting bank erosion rates as well as annual sediment yield budgets.
The USEPA has peer-reviewed and recommended the WARSSS methodology for use in establishing “clean sediment” TMDL’s as a watershed-based assessment protocol. The WARSSS textbook (Rosgen, 2006) documents the WARSSS methodology.
WARSSS is also used for river restoration to identify the cause, extent and location of river impairment, and is also used for comprehensive watershed management and planning, cumulative effects analysis, fish habitat evaluation, riparian grazing management, flood studies and geomorphic studies.
The all-day workshop will describe the various aspects of the procedure and its application to water resource management with a focus on urban watersheds.
This workshop will familiarize participants with the principles, fundamentals and procedures of this quantitative cumulative watershed assessment methodology. The applications of the WARSSS methodology provide the following:
- A mechanism to put fundamental geomorphic principles into practice;
- A consistent, quantitative and comparative analysis that minimizes subjective
- Watershed-based and specific river reach assessments;
- Linkages between various land uses and their associated sources of accelerated sediment supply;
- A procedure that rapidly prioritizes high-risk sub-watersheds and river reaches at broad “screening” levels yet provides for more detailed assessments;
- Methods to assesses the probability, risk and potential consequences of sediment problems despite inevitable gaps in knowledge, large uncertainty and spatial and temporal variability;
- A companion assessment that can be related to aquatic habitat;
- Understanding the quantitative changes in the hydrology, hillslope and channel
processes due to past and/or proposed land use activities;
- Process-specific mitigation for impaired stream systems
- A TMDL for clean sediment using a pro-active procedure that identifies the extent, location, source(s) and processes related to disproportionate sediment supply and corresponding impaired streams;
- Assistance in the design of stream rehabilitation/restoration and river enhancement projects; and
- A baseline assessment for water resource inventory, land management accountability and procedures for watershed and river system monitoring.
- Channel stability rating procedure, including the Reconnaissance Level Assessment (RLA), The Rapid Resource Inventory for Sediment and Stability Consequence (RRISSC) and the Prediction Level Assessment (PLA).
- The BANCS model to predict total annual streambank erosion.
- Sediment competence/entrainment procedure.
- The FLOWSED and POWERSED models to predict total annual sediment yield and sediment transport capacity. Comparisons of predicted versus observed sediment transport data will be presented. Test case examples from Alaska, Montana, Maryland, Tennessee and North Carolina will be demonstrated.
- Overall sediment supply ratings related to specific sources, processes and locations.
11210 North County Road 19 Fort Collins, CO 80524 (970) 568-0002 phone (970) 568-0014 fax