How to Reduce/Improve Runoff from your Roof, Driveway, Parking Lot

Tips for Getting Stormwater into the Ground Rain Garden on Monticello Ave

Did You Know?
Nearly 50 percent of our watershed is covered by impervious, not allowing fluids to pass through, surfaces. That number includes our driveways, sidewalks, patios, rooftops and parking lots. Another way of looking at from an environmental and cost perspective, HALF of our Spa Creek watershed does not allow rainwater to percolate naturally into the ground. This is one of the major challenges Spa Creek and other urban watersheds face today!


Why are Impervious Surfaces a Problem?
In its natural state, the land itself is usually able to control the runoff of water.  Most of it is absorbed into the ground and slowly released into creeks and rivers.  This process minimizes pollution and flooding.  Spa Creek is an urban environment surrounded by buildings, roads and other impervious surfaces that have replaced permeable vegetation. As a consequence, the natural flow and absorption of rainwater has dramatically changed.  The result is high scouring flows and flooding from the increased speed and velocity of the rainwater.

Why Should I Reduce Impervious Surfaces?
As water flows over paved surfaces, it collects and carries soil, pet waste, salt, fertilizers, oils, and other pollutants into our creek.  Our shorelines are eroding and loads of sediments are being deposited.  These sediments are deadly to aquatic life.  Even if your house or business is not near a stream or river, the polluted runoff flows down the street, into the storm drain system and is carried to the nearest body of water.

How Can I Reduce Impervious Surfaces at my Home?  At my business?
When adding, repairing or rebuilding driveways, patios and garden pathways, consider using paving blocks, permeable pavements, grass driveway strips, wood decks, wood hips and crushed rock rather than concrete or asphalt.  Permeable surfaces allow rainwater to soak through and help reduce and improve the quality of storm water runoff.

Wood Decks
Wooden decks will allow rainfall to flow between the boards and percolate into the soil underneath.  In selecting the timber for your deck, avoid wood treated with chemical preservatives that may leak into the groundwater.

Paving Blocks
There are types of paving blocks that substitute grid or lattice holes for solid concrete.  These holes may be filled with solid and planted with grass, or they may be filled with gravel.  A fraction of storm water runoff will be trapped in the shallow depressions, and some storm water may actually infiltrate into the soil.  Not only do paving blocks help reduce runoff, they offer an attractive alternative to pavement.  Traditional bricks may also be used.  As you lay them out, leave space in between the bricks.  Fill the space with sand and the effect on storm water will be the same.

Choose a Permeable Pavement
Permeable pavement or concrete is similar to traditional pavement, except that the gravel used in the mix is larger.  The larger gravel helps rainwater percolate better.  Check with contractors for specific information about the types of paving materials that may be best for your parking area.

How May Good Creek Neighbors Control and Improve Runoff?
Did you know -- residential irrigation accounts for nearly 40% of domestic water consumption in a given area.

Keep your gutters clear and equip downspouts with aprons that carry water away from your roof or paved areas onto permeable landscaped areas.  In this way, you will reduce the need for water, reduce the flow of water and increase the infiltration of water through the soil.  Redirect down spouts to gardens or rain barrels.

Buy or Build a Rain Barrel
Using a rain barrel during storms can lower your water bills and decrease water demand during the hot summer months.  Rain Barrels help the environment by preventing the pollutants such as oil and grease, bacteria, and nutrients from flowing into the storm sewers and ultimately into our creek.

A rain barrel collects and stores runoff from your roof for later use on your lawn and garden, for car washing and even for cleaning windows.  The more rainwater we reuse, the less demand there is for chlorinated or chemically treated tap water.

Purchase a rain barrel at most major lawn and garden centers.  Or you may make a rain barrel using a large trash can and a little ingenuity.  Below are some useful links with information on rain barrels.

How do I Install a Rain Barrel?
To install a typical barrel, disconnect your downspout, cut off a portion of the downspout and redirect into the top of the barrel.  Most rain barrels have an overflow pipe that when full will redirect  the rainwater back into the downspout or onto your lawn or other surface.

Plant a Pleasing Rain Garden
Rain Gardens are planted/landscaped areas designed to catch, hold and filter rainwater.  This prevents rapid runoff/flooding and removes pollutants from the water as it infiltrates the garden soil.

Grass Swales
Grass Swales are slight depressions in lawn areas that allow heavy rains to infiltrate the ground slowly, thereby reducing flooding.

Install a Green Roof
Also called a ”Living Roof”, this attractive runoff reducer consists of a thin layer of soil and native plant material over a conventional flat or even sloped roof.  The vegetation may range from turf grass to shrubs or even trees, depending on the climate and the load bearing capacity of the roof providing habitat for endangered pollinators.

Roof top areas can range from 35% to as high as 75% of the impervious surface on a building. A green roof can hold over 40% of the rain that falls on it - - up to 80% in a given rainfall - - more in summer months.  For this reason, and the aesthetic value of a “living roof”, its potential for enhancing energy conservation, increasing air cooling, and air pollution control, a green roof is worthy of your consideration.
•    Redirect your down spouts to gardens or rain barrels
•    Install a Rain Barrel and/or Install a Rain Garden
•    Replace impervious surfaced driveways, patios, and parking lots with Eco pavers