SWET

Software


Projects

Watershed Assessment Model Myakka River Basin Lower St. Johns River St. Johns River Suwannee River Suwannee River Revisited WAM Modifications C-43 Basin Lake Okeechobee Watershed Project Deep Creek Basin Okura Basin WAM/WASP for DO in S-191 Hillsborough River Basin Hydrologic & Contaminate Transport Modeling EAAMOD - EAA EAAMOD - Okeechobee LOADSS Update Dairies Alliance Dairies Lake Okeechobee Basin Dairies Best Available Technologies Project Design Projects Waste Management Systems Piedmont Dairy

Lower St. Johns River -- Subbasins Hydrologic/Water Quality Modeling

The purpose of the SJRWMD project was to extend the GIS based watershed model development effort to unmodeled subbasins in the Lower St. Johns River Basin that are identified as major contributors of pollutant loading to the mainstem. This was a followup project to the original Lower St. John WAM project entitled St. Johns River Watershed Assessment Project. Three major subbasins were covered in this project: (1) Black Creek subbasin; (2) Julington Creek subbasin; and (3) OrtegaRiver subbasin. WAM was calibrated on the Black Creek subbasin and validated on the other two basins in order to access the ability of WAM to simulate pollutant loadings on ungauged basins, which is a major issue in this region. The following requirements were specified by the District:

The models shall be well tested, verified, and documented.
The models shall be GIS linked.
The major source of GIS input data for calibration of the models shall be the District's GIS database. GIS products resulting from this project shall be compatible with the District's GIS database.
Aerial distribution of rainfall shall be estimated using Thiessen polygons, or another suitable method.
The models shall be capable of simulating the processes responsible for delivering loads to receiving water body, including runoff and non-point source pollutants.
The models shall be capable of simulating the effects of Best Management Practices (BMPs), which requires the capability to reflect changes in agricultural operations and overall land use in model output such as changes in runoff, nutrient loads, and suspended solids.
The models shall be capable of interfacing with the receiving water body model. The receiving water body model input requirements are tidal and wind driven water surface elevation (30 minute time intervals), daily time steps, mean discharge in cfs, and pollutant loads in kg, lbs or concentrations in ppm.

WAM utilizes process-based models in its simulations in order to minimize calibration data requirements and to enhance the development of management alternatives. This project demonstrated WAM's ability to accurately simulate ungauged basins.