Plan Your Project
Manage Stormwater Runoff in Your Own Back Yard
Do-it-yourself stormwater solutions are simple practices that capture rain and snowmelt from roofs, driveways, patios, and even lawns and encourage it to soak into the ground. Find everything you need to complete your SOAK project on our Resources page.
5 Easy Steps to Soak Up the Rain
STEP 1: Observe Property
To determine if a property is well-suited for a SOAK project, walk around the property and observe any problems or opportunities. A SOAK project can help protect water quality even if no obvious problems exist.
Observe where stormwater comes from, where it goes, and any problems that it may cause along the way.
- Look for site constraints such as shallow bedrock or steep slopes in areas of the property where a SOAK project is being considered.
- Test soils to determine whether infiltration is possible with a Simple Perc Test and the type of soil with a Soil Ribbon Test.
- Consider the slope for each area on the property where a stormwater practice is being considered. Some practices should not be installed on slopes.
- Sketch and photograph the property to record your observations and measurements.
STEP 2: Select a Stormwater Practice
One you have observed the property and determined it is a good candidate for a SOAK project, select one or more stormwater practices to install. Use the information you collected and the flow charts below to get you started.
Infiltration Practice Flow Chart: Infiltration practices allow water to soak in.
Conveyance Practice Flow Chart: Conveyance practices move water from one location to another, preferably to a location where it can infiltrate.
Once you have made a selection, verify that the practice is a good match for the property and the site by reading through the Do-It-Yourself Fact Sheet for the selected practice.
Step 3: Design
Now that you have selected a stormwater practice to install, use the DIY fact sheet to completed the design.
Basic steps for most practices include:
- Determine the total drainage area being directed to the stormwater practice.
- Calculate the runoff volume from the drainage area. Ideally, the practice should be sized to hold at least the volume of runoff from a storm that produces 1 inch of rain.
- Size your practice using the instructions on each DIY fact sheet. The Rain Garden Calculator, provided by Three Rivers Rain Garden Alliance, can be a helpful design tool.
- Determine materials needed by referring to the DIY fact sheet.
- Develop a planting plan, if needed, for practices that include plants, such as rain gardens and vegetated swales. The Native Plants for New England Rain Gardens provides a useful list.
- Determine the stormwater footprint, if desired. A “stormwater footprint” is the amount of stormwater runoff and associated pollutants that a property creates. Use the NH Residential Loading Model available from the Winnipesaukee Gateway to estimate yours.
Now that you have chosen and designed your practice, here are a few tips to help your installation day run smoothly.
- Recruit volunteers. You will likely need a number of helpers – friends, family, local youth groups, or volunteer groups – on hand to help on installation day.
- Order Materials. Order materials and arrange for pick-up or delivery in advance of the scheduled installation day.
- Mark outer boundary of the practice. Use a garden hose, stakes and string, spray paint, or some other method. Include any berms or retaining walls.
- Call Dig Safe. Before digging on your property, state law requires that you call Dig Safe at least 72 business hours in advance of digging to ensure no utility lines are buried in your project area. This is a free service, but the outer boundary of the project area must be clearly marked prior to the visit.
- Gather Equipment. Most stormwater practice installations require only hand tools. If you plan to use heavy equipment, like a mini excavator or other machinery, and live within 250 feet of a waterbody, determine whether a Shoreland Water Quality Permit is needed.
- Time Frame Guide:
- 2 months before installation: Begin recruiting volunteers
- 1 week before installation: Order bulk materials; shop for plants
- 4-5 days before installation: Call Dig Safe – Mark boundaries of areas to dig
- 1-2 days before installation: Pick up bulk materials; remind volunteers
- Installation day: Hand out copies of the plan (if using) and assign tasks
STEP 5: Maintain
Most maintenance practices are similar to typical home and garden activities and can be completed by the property owner. By following the general maintenance steps below, a stormwater practice should continue working to protect water quality. Maintenance recommendations for individual practices are included in the fact sheets.
- Periodically and after rain events, inspect the practice for any obvious signs of stress or failure.
- Remove accumulated debris and sediment as needed.
- Check for ponding or slow draining water – this can be a sign of clogging.
- Water new plants frequently until their roots are established.
- Weed as necessary in the first few years until plants become established.
- Check plants for signs of stress, disease, and die-off and replace as needed.
- Initially 2” – 3” of mulch should be used to maintain soil moisture.
- Replenish mulch when needed.
- Once the plants are established (2-3 years), mulch may not be needed.
- Other Materials
- For practices with stone and other materials, periodically remove accumulated sediment, debris, and weeds.
- Practices lined with geo-textile fabric can clog over time.
- Check for ponding or slowly draining water. If clogged, remove and wash the stone to clean out the accumulated sediment and debris.