Exercise for Module 2

Preventing Stormwater Pollution at Your Public Works Facility

Exercise for Module 1

Following the flow

The purpose of this exercise is for your staff to start noticing how stormwater runoff flows through the facility, and to be aware of where it eventually ends up.

Materials needed: o Flip chart paper (sticky-backed is good, or have tape for hanging) o Markers o Scrap paper o Pens or pencils o Recent air photo or other map of your facility and the surrounding area1 o Site plan of your facility with elevations, if available2 o List of drinking water supplies, other DEM special resource protection waters (DEM Water Quality Regulations) and impaired waters (DEM 303d list). (This information may be obtained from the MS4’s Storm Water Management Plan, the Planning Department, or from DEM interactive map server).

Step 1) Break into groups of 2-3 people each, and provide each group with flip chart paper and different colored markers. Make sure each group has a blue marker and ask them to set it aside for the moment.

Step 2) Ask each group to draw a rough map of the facility property, making the outline as large as possible, while still leaving enough room on the paper to also make notes outside of the property lines. Have them locate all permanent structures on their maps (e.g. buildings, pavement, and gas pumps). They should feel free to use any of the maps you have (the air photo and/or site plan maps).

Step 3) Ask each group to think back to the last time it rained enough to cause the water to start to run. Where did the water concentrate into little rivulets? What direction was it flowing? Where did it come from? Where did it eventually end up? Where does the water leave

11 Visit http://maps.google.com/ and you can get an aerial image of your site 2 You can get a print of a basic elevation map from the web at http://www.dem.ri.gov/maps/index.htm. Click on Environmental Resource maps, then click on the folder at “image layers” and make sure elevation is checked. You’ll need to zoom in fairly close to your site on the state map before the images will appear. You might also be able to ask your Planning Dept. for a map.

Module 1: Introduction to the Series and Why Stormwater Matters Exercise 1 Preventing Stormwater Pollution at Your Public Works Facility your property? Have the groups mark these “flow paths” on their maps, using the blue markers to draw arrows. If the runoff goes into a pipe system, have them draw a solid line to show where the pipe goes.

If the groups are having trouble envisioning the flow paths, or don’t know where the pipes go, take them outside to see, or refer them to the elevation map of the facility.

Step 4) Have each group post their maps on the wall and look at the results from the other groups. Make sure there is a general agreement on where most of the runoff leaves the site. Then hand out copies of the air photo (if you haven’t already), and work with the staff to locate the facility and the discharge point. Have them draw a line from the facility’s discharge point to represent where the water would go from there.

When the water leaves the site does to pass to a local stream, pond, etc. Where does it eventually go? Ask staff to name the nearby and downstream waters that receive facility runoff, and describe their use and condition. For example, are they used for fishing or swimming areas; do they drain to coastal waters? Are they high quality or do they have problems? Following discussion, distribute or display a list of drinking water supplies, special resource protection waters and impaired waters downstream from the facility. If space is available on the map, have staff label these important water resources.

Step 5) Keep the maps on the wall for the next week or so, and invite staff to add to them/make corrections as they watch actual runoff patterns form.

Module 1: Introduction to the Series and Why Stormwater Matters Exercise 2