River Basin Characteristics
The Cattaraugus Creek watershed is located on the southernmost portion of Erie County, the northernmost portion of Cattaraugus, and the northeast corner of Chautauqua counties in New York. Cattaraugus Creek forms the dividing line between these counties. The watershed also extends into portions of Allegany and Wyoming County. The general flow direction of the watershed is from East to West with the discharge point into Lake Erie.
Clear Creek watershed is a smaller sub-watershed of the larger Cattaraugus Creek watershed which is contained within Cattaraugus County, Erie County, and the Seneca Nation of Indians (SNI) territory. The topographic relief of the Cattaraugus Creek watershed is expressed as gently rolling hills and ranges in elevation. Most of the watershed (78 percent) has a slope value under 5 percent and no value over 20 percent.
The dominant land cover classes in the watershed are forested areas and cultivated lands (woody wetland, deciduous forest, as well as cultivated crops, pasture/hay). There are some areas of residential and commercial land use, but they occupy less than 1 percent of the land-use cover.
Concern has been expressed that agricultural activities and land-use management practices upstream within the Clear Creek sub-watershed may have a negative impact on soil erosion, flooding and water quality within the lower reach of the sub-watershed.
The coordinated model development and iterative estimation and calibration study for the ungaged Clear Creek sub-watershed included several components. Estimates of streamflow statistics for ungaged sites were obtained by using the USGS StreamStats. In order to calibrate and validate the hydrological and sedimentological modeling for the Clear Creek, the project team used these streamflow estimates, flood event-based extend and stream bank collapse/relocation recordings by the SNI, as well as multi-temporal topography.
The simulation was calibrated based on flood stage and other observations from the 2009 winter and summer flood events. The first component of the coordinated model development utilized the combined Water Erosion Prediction Project (WEPP) / Geo-spatial interface for WEPP (GeoWEPP) to complete detailed modeling of sediment sources and sinks on hillslopes and small channels in the Clear Creek for the days of the flood events as well as continuous modeling to determine long-term annual averages and return intervals of extremes.
Secondly, the already calibrated and validated Soil and Water Assessment Tool (SWAT) / ArcGIS-ArcView Soil and Water Assessment Tool (ArcSWAT) baseline model simulation for the Cattaraugus Creek (previous project) was used in a sub-watershed simulation to allow spatially less detailed watershed simulation at the basin scale for the entire Clear Creek. These results were compared with results from the first component and fed into the third component.
Lastly, the linked Hydrologic Engineering Centers River Analysis System (HEC-RAS) / Hydrologic Engineering Centers Geospatial River Analysis System (HEC-GeoRAS) model application allowed a very detailed modeling of flooding, scouring, sediment transport and deposition in the larger channels of the Clear Creek for the days of the flood events in 2009. These results were used to assist calibrating or validating the first two components.
Use and Applications
There were three primary goals for the project. The first goal was to simulate erosion, sediment delivery pathways and sediment delivery yields and loads in the watershed. The second goal was to project the potential benefits of conservation treatment strategies and best management practices (BMPs). The third goal was to support the larger conservation effort to reduce erosion in the Cattaraugus Creek Basin and reduce sediment delivery to Sunset Bay at the mouth of the Cattaraugus Creek.
The first year of the project was aimed at developing and validating the tools by the team. The results obtained by the models allowed the team to provide technology and knowledge transfer to different stakeholders during the second year. And at the conclusion of the project, the team delivered the modeling software, enhanced data, user guides, baseline models, as well as BMP scenarios on consistently configured laptops to each of the stakeholder organizations.
- State University of New York at Buffalo – Landscape-based Environmental System Analysis & Modeling Laboratory
- U.S. Department of Agriculture – Natural Resources Conservation Service
- Seneca Nation of Indians
- New York Soil and Water Conservation Districts