Using the Source Loading and Management Model (WinSLAMM)

Transcription

1 Using the Source Loading and Management Model (WinSLAMM) Robert Pitt The University of Alabama, Tuscaloosa, AL John Voorhees and Caroline Burger PV& Assoc., Madison, WI Presented by: Shirley E. Clark, Ph.D., P.E. Penn State Harrisburg

2 PV & Associates LLC

3 Purpose of the Source Loading and Management Model (SLAMM) Developed to evaluate the benefits of alternative stormwater treatment practices for both runoff quality and quantity in existing and developing urban areas.

4 Unique Features of WinSLAMM Continuous simulation model with actual rainfall data as a primary input. Based on actual monitoring results at many scales and conditions. Early research project results (1970s) did not conform to typical stormwater assumptions (especially rainfall-runoff relationships and sources of pollutants). Initial model versions focused on site hydrology and particulate sources and transport (and public works practices). Other control practices added as data become available.

5 Main Menu Window without a.dat File

6 Some of the other land uses and source areas included in WinSLAMM

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8 Can use local rain data over a period of record. Select the Edit Buttons to Enter or Change values

9 Stormwater Controls Included in Bioretention/biofiltration areas (Rain gardens) Porous pavement Grass swales and grass filters Infiltration basins Infiltration trenches Green (and blue) roofs Disconnections of paved areas and roofs from the drainage system Also considers evapotranspiration and stormwater beneficial uses Detention ponds WinSLAMM SEA (Street Edge Alternative) Street, Seattle, WA

10 Grass Swales Data 116 ft 75 ft TSS: 10 mg/l TSS: 20 mg/l 25 ft TSS: 30 mg/l 6 ft 3 ft 2 ft TSS: 63 mg/l TSS: 35 mg/l Head (0ft) TSS: 102 mg/l TSS: 84 mg/l University of Alabama swale test site at Tuscaloosa City Hall

11 WinSLAMM Road Swale Description 11

12 Porous Pavement Zurich Essen, Germany Singapore

13 Porous Pavement Installations

14 Rain Gardens/ Biofiltration/ Bioretention

15 Rain gardens for local conditions

16 Reduction in Annual Impervious Area Runoff (%) Annual Runoff Reductions from Paved Areas or Roofs for Different Sized Rain Gardens clay (0.02 in/hr) silt loam (0.3 in/hr) sandy loam (1 in/hr) Rain Garden Size (% of drainage area)

17 Green Roofs The main roof runoff removal mechanism for green roofs is evapotranspiration. These are central Alabama monthly ET values and the plant and substrate characteristics used in these analyses.

18 Rainwater Harvesting Calculations in WinSLAMM WinSLAMM conducts a continuous water mass balance for every storm in the study period. Model fills the tanks during rains (up to the maximum amount of runoff from the roofs, or to the maximum available volume of the tank). Between rains, the tank is drained according to the water demand rate. Excess water from the event would be discharged to the ground or rain gardens after the tank fills.

19 Output

20 Percentage reduction in annual roof runoff Use of WinSLAMM Outputs: Reductions in Annual Flow Quantity from DC Roofs with Rain Barrels and Water Tanks (Kansas City CSO Study Area) Rain barrel/tank storage (ft 3 per ft 2 of roof area)

21 Interaction Benefits of Rain Barrels and Rain Gardens in the Kansas City CSO Study Area Reduction in annual roof runoff (%) # of rain barrels per house # of rain gardens per house Two 35 gal. rain barrels plus one 160 ft 2 rain garden per house can reduce the total annual runoff quantity from directly connected roofs by about 90%

22 Reductions in Runoff Volume for Cedar Hills (calculated using WinSLAMM and Type of Control verified by site monitoring) Runoff Volume, inches Pre-development 1.3 Expected Change (being monitored) No Controls % increase Swales + Pond/wetland + Infiltration Basin % decrease, compared to no controls 15% increase over predevelopment

23 Monitored Performance of Controls at Cross Plains Conservation Design Development Water Year Construction Phase Rainfall (inches) Volume Leaving Basin (inches) Percent of Volume Retained (%) 1999 Pre-construction % 2000 Active construction % 2001 Active construction % 2002 Active construction (site is approximately 75% built-out) % WI DNR and USGS data

24 Sediment Reductions Volume Reductions North Huntsville Industrial Site (AL)

25 Uses ICM to Evaluate Receiving Water Impacts

26 WinSLAMM licensing arrangement with PVA Buy a copy of the program, get one license Free upgrades for a year after you buy it, downloadable from the web site ( After a year, to upgrade you must purchase a renewal license (at a reduced rate)

27 WinSLAMM licensing arrangement with PVA You may install WinSLAMM on as many of your office computers as you want. However, only use the program on however many computers you have licenses for at one time at the office that has the program. So, if you have one license, only one person may use the program at a time.

28 Contacting WinSLAMM Contact us at or Version 10 in beta testing currently

29 More Flexible Source Area Options Number of Source Areas for a Land Use Current Number Current SA Number Range Final SA Count SA Number Range Roofs Paved Parking Unpaved Parking Driveways Sidewalks Streets Large Landscaped Areas Small Landscaped Areas Undeveloped Areas Playgrounds Isolated Areas Water Body Areas Other Pervious Area Other Directly Conn Imp Area Other Partially Conn Imp Area Total 30 Paved Land and Shoulder Area Large Turf Areas Undeveloped Areas Other Pervious Areas Other Directly Conn Imp Area Other Partially Conn Imp Area

30 Drag and Drop Interface

31 Source Area Control Practice Routing

32 Needed Changes to the Program Drainage System Control Practice Routing