Site Description: Watershed Example (anything descriptive can be used)

Transcription

1 Watershed Example For this example, we will model a watershed using the default standard land uses in the model. Then we will add a wet detention pond followed by an infiltration basin at the outfall of the watershed. The watershed is acres of mixed land use. The data on the following pages describes the land use and soil types in the watershed. Figures of the watershed and landuses are found at the end of this document. Enter the following data into a new WinSLAMM model file. Note: You cannot save a file until at least one source area is entered. Parameter Files: Select Current File Data Site Description: Watershed Example (anything descriptive can be used) Seed: -42 (a negative seed value disables the random pollutant generator and uses mean pollutant concentrations only) Rain File: WisReg Madison WI 1981.ran Rain Start Date: 01/01/81 Rain End Date: 12/31/81 Winter Season Date Range: December 2nd March 12th The following parameter files are the most recently calibrated files available: Pollutant Probability Distribution File: WI_GEO02.ppdx Runoff Coefficient File: v10 WI_SL06 Dec06.rsv Particulate Solids Concentration File: Wl_AVG01.pscx Street Delivery File: Residential LU: WI_Res and Other Urban Dec06.std Industrial LU: WI_Com Inst Indust Dec06.std Institutional LU: WI_Com Inst Indust Dec06.std Other Urban LU: WI_Res and Other Urban Dec06.std Commercial LU: WI_Com Inst Indust Dec06.std Freeways: Freeway Dec06.std Select Continue when finished to save your edits and leave the form. Note: Screen Captures of the entered data are found on the subsequent pages. Page 1 of 17

2 Page 2 of 17

3 Pollutants: Select Pollutants. Check the box next to Total Lead (Particulate Solids (or TSS) will always be checked). Select Continue to exit the form. Watershed Data Build the model network and add the data describing the watershed. Table 1 Watershed Data Land Use Area Sandy Silty Clayey Land Use Code (ac) (ac) (ac) (ac) LDR Low Density Residential MDRNA Medium Density Residential No Alleys OSUD Open Space Undeveloped PARK Park SCH School WTR Water 5.5 Total Page 3 of 17

4 First, add the land use icons for each type of land use. LDR Residential MDRNA Residential OSUD OPEN - Other Urban Park Other Urban School Institutional Page 4 of 17

5 Right click on one of the Residential Icons to enter the Low Density Residential data. Then select Apply Standard Land Use Next, double click on Low Density Residential LDR in the left window. The source areas in the land use will appear in the right window. In the boxes below the left window, enter the acres of each soil type within the land use. Next, select Create Land Use and Exit. The program will create the data for the Low Density Residential Land Use and rename the Icon Name to Low Density Residential. Page 5 of 17

6 Select the Low Density Residential label to view the source areas in the source area grid. Complete these same steps for the next four land uses (MDRNA, OSUD, PARK, SCH) Page 6 of 17

7 MDRNA OSUD Page 7 of 17

8 PARK SCH Page 8 of 17

9 A default SLU is not available for Water. Therefore, this area will be added into a land use that was just created as a Water Body Areas source area. Highlight the Open Space land use that was just created. Scroll down to the Water Body Areas source area. Enter 5.5 acres. Page 9 of 17

10 Next, check that the total area in the model files matches the watershed area. Page 10 of 17

11 Add the Drainage Control Practice Icons for the Wet Detention Pond and Infiltration Basin. Add the appropriate number of junctions. Connect the network. Page 11 of 17

12 Add the following data into the Wet Detention Pond Form. Page 12 of 17

13 Enter the data for the Infitlration Basin Page 13 of 17

14 If you haven t already done so, Save the File by selecting File, then Save Project File AsE Navigate to your project folder, name the model file, and select Save. Page 14 of 17

15 Running the File: To run the file either select Run, then Current Project File. Then, select Save File and Execute. Or, select the S/R Icon in the Main Tool Bar It will resave the file with the same name originally chosen in the project directory it was created. Page 15 of 17

16 Results: Runoff Volume: 2,214,000 cu ft Runoff Volume Percent Reduction: 61.8% Particulate Solids Concentration: 54.5 mg/l Particulate Solids Yield: 7,535 lbs Particulate Solids Percent Reduction: 83.3% Total Lead : 1.5 lbs Total Lead Percent Reduction: 80.6% Rv: 0.07 Approx. Urban Stream Classification: Good Page 16 of 17

17 Review the effectiveness of each control practice. How could they be modified to achieve a higher runoff volume or particulate solids reduction? Page 17 of 17

18 Legend Watershed Boundary ± Watershed Outfall ,200 Feet

19 Legend Watershed Boundary WinSLAMM Landuse LDR MDRNA OSUD PARK SCH WTR Watershed Outfall ± ,200 Feet