your backyard rain, runoff and - albemarle county, … rain, runoff and your backyard albemarle...

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Rain, Runoff andYour Backyard

Albemarle County

City of Charlottesville

Rivanna Water and Sewer Authority

University of Virginia

Virginia Department of Transportation

Thomas Jefferson Soil & WaterConservation District

The Rivanna Regional StormwaterEducation Partnership was formed bylocal entities holding stormwaterpermits to educate the public aboutstormwater issues. The ThomasJefferson Soil and Water ConservationDistrict is the partnership’scoordinating body.

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In the beginning

Before people developed the land itwas covered with plants that allowedmost rainfall to sink into the earth.Plants also helped prevent erosion, andreduce the amount of pollutionreaching waterways in stormwaterrunoff through filtration and nutrientuptake.

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IMPERVIOUSIMPERVIOUSCOVERCOVER

When the land is developed, thesurface is covered with imperviousstructures such as parking lots, roofs,streets and sidewalks. This increasesthe amount of stormwater runoff,because it cannot sink into the earth. Inaddition, various pollutants are left onthese surfaces and washed intowaterways by runoff.

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Stream Impacts

8-108-10%

2020%

30%30%> 65%> 65%

< 5%< 5%

Slide Courtesy of TheCenter for Watershed Protection

As the surface of the land is coveredwith impervious surfaces, the increasein stormwater runoff causes greatdamage to streams. Stream banks arewashed away and the stream bottom isscoured. The greater the percentage ofimpervious surface in a watershed, thegreater the damage to streams when itrains.

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Storm Drain

In order to prevent flooding,stormwater is removed by means ofstorm drains, which empty into...

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Stormwater Outflow Pipe

... the nearest creek or river, as in thephotograph above, or…

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Stormwater Basin

…into a stormwater basin. The waterin a stormwater basin is graduallyreleased through a pipe, reducingdamage to streams. Much of thepollution remains in the basin.Stormwater basins are, however, aliability in terms of danger to children,the need for maintenance and becausethey are a breeding ground formosquitoes.

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Watersheds

A watershed is an area of land thatdrains down to one point. In thegraphic above, rainwater drainsdownhill from higher ground on theridges around the watershed down totributaries, which all converge at thelowest point at the bottom of thewatershed in the lower right corner.

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TheChesapeake

BayWatershed

You Are HereRivanna River

James River

Charlottesville is in the Rivanna RiverWatershed, which is part of the largerJames River Watershed, which is partof the enormous Chesapeake BayWatershed (represented here by thedarker green area). Pollution that entersthe Rivanna River flows to the JamesRiver and ends up in the ChesapeakeBay. People living upstream have aneffect on people living downstream inthe same watershed.

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Impervious Surfaceson the Albemarle High School Campus

roofs

As a local example, Albemarle HighSchool has a large amount ofimpervious surface including roofs,…

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sidewalks

roads

…sidewalks, roads…

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parking lots

…and parking lots.

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Stormwater Structureson the Albemarle High School Campus

Stormwater on the western side of thecampus goes down stormdrains…

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In the background you can see thestructure to which all these drainschannel stormwater…

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We look over the fence at..

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The riser in a stormwater basin.

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On the eastern side of the AlbemarleHigh School campus, all stormwater isdrained by means of concretechannels…

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…which send the flow through pipesacross the road and into…

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Effects of Stormwater

…a small creek. These exposed treeroots are evidence of the damage tothis stream caused by large quantitiesof stormwater runoff.

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Effects of Stormwater

The creek has been severely eroded bystormwater that is sent unchecked intothe stream when it rains.

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Is there a better way?

Are there better ways of managingstormwater runoff?

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Albemarle County Office Building

Green RoofGreen Roof

The Albemarle County Office Buildinghas a “green roof” which mitigates theproblems caused by impervioussurfaces. The roof stores water forthese plants to use, reducing runoff.The plants remove nutrients and otherpollution from the water, and much ofthe water is returned to the atmosphereby means of evaporation andtranspiration.

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Albemarle County Office Building

Green RoofGreen Roof

Once the plants have grown andcovered the surface of the roof (whichwill take about a year), the buildingwill also benefit from the insulationprovided by plants. The building willbe cooler in summer and warmer inwinter.

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Dell Stormwater PondDell Stormwater Pond

The University of Virginia has createda stormwater basin that functions as anattractive pond.

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Dell Stormwater PondDell Stormwater Pond

The Dell Stormwater Pond provides abeautiful natural landscape as itmanages stormwater runoff.

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Rain GardensRain Gardens

Raingardens provide a means ofmanaging runoff that is similar tonatural pre-development processes.

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Making a Rain GardenMaking a Rain Garden

dig a holedig a hole

Dig a hole in a low spot to whichrunoff naturally drains. The suggesteddimensions are 30 feet long by 10 feetwide by 4 feet deep, although a smallergarden can also provide benefits.

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add sandadd sand

Fill the bottom with a foot of sand toprovide a water storage area.

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Fill the rest with good soilFill the rest with good soil

50-60% sand20-30% top soil

20-30% leaf compost

Fill the rest with soil that allows waterto sink into the ground quickly.

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Plant trees, bushes andPlant trees, bushes andground coverground cover

Use native plants that have a tolerancefor both wet and dry conditions.

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Add mulchAdd mulch

Add mulch to soak up water and keepplants healthy during dry periods.

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Cross Section of a Rain GardenCross Section of a Rain Garden

runoff

Filtration

Nutrient Uptake

Storage

To Groundwater

Bacteria and fungusprocess pollutants

The rain garden filters pollutants out ofrunoff, the plants remove nutrients andthe garden stores excess runoff for upto two days. Bacteria and fungus in thesoil break down pollutants, and thegroundwater is recharged.

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Charlottesville’s Greenleaf park

Rain GardenRain Garden

The City of Charlottesville has built alarge rain garden in Greenleaf park

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Charlottesville’s Greenleaf park

Rain GardenRain Garden

The Greenleaf Park Rain Garden isboth functional and educational.

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200 cubic feet of water= 1500 gallons

(50 gallons/day for a month)

2-Inch RAIN STORM

30’x40’ ROOF (1,200 sq. ft.)

Rainwater HarvestingRainwater Harvesting

Rainwater harvesting is another way tomanage stormwater runoff. A two-inchrainstorm that falls on a 1,200 squarefoot roof will provide 1,500 gallons ofwater. That is enough water to provide50 gallons a day for a month.

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START SMALL . . .

Rain barrels are an easy way to collectsome rainwater and reduce runoff.

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11 rain barrelsprovide over 600gallons of water

storage(.8” rain on 1,200

sq.ft. roof).

Add more rain barrels for increasedcapacity

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. . . EVOLVE TO SOMETHING BIG

(Photo - courtesy of American Rainwater Catchment Systems Association)

A large cistern can provide all thewater for household or landscapingneeds.

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Another simple rainwater harvestingsolution.

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This arrangement in Texas providesboth shade and water for livestock.

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What else can you do?

Have your soil tested. (Extension: 872-4580)

Follow instructions.

Don’t fertilize before abig rain.

Fertilize in the Fall.

Lawn CareLawn CareUsing too much fertilizerturns the water green!

If you use too much fertilizer theexcess is washed into waterways by therain. Have your soil tested to determinehow much fertilizer you really need(call the local Extension Service), andfollow the instructions on fertilizerbags . Don’t fertilize if there is aforecast for rain. Fertilize in the fallwhen weather patterns are less likely towash fertilizer away, and to promoteroot growth.

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1 quart of motor oil can contaminate250,000250,000 gallons of water!

Recycle used motor oil

Recycle hazardous waste:• antifreeze

• paint

• cleansers

Used Motor OilUsed Motor Oiland other hazardous wasteand other hazardous waste

Recycle motor oil and other hazardouswaste. Never pour them down stormdrains or household drains. Dumped onthe ground, they may find their way tothe groundwater.

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Every time it rains,runoff from your lawncarries bacteria andother organisms fromyour pet’s waste intolocal streams.

Bag pet waste andthrow it in the trash.

Pet WastePet Waste

Pet waste can pollute waterways withbacteria and excess nutrients if notproperly disposed of.

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Wash your car on the lawn.

Use biodegradable cleaning products. Use a carwash that recycles water.

Washing VehiclesWashing Vehicles

Wash your car on the lawn so that thewater will sink into the ground and willfilter out pollutants. If you wash yourcar in the street, the dirty soapy waterwill go down a stormdrain and maypollute a local waterway.

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Keep a bufferbufferof trees on eachside of a stream.Never mow your

lawn right to theedge of a stream.

StreamStreamBuffersBuffers

Forested buffers help protect streamsfrom erosionand keep pollution out ofthe water.

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Inspect regularly.

Have it pumped when needed.

Never send these down the drain:•oil

•kitty litter

•paints, thinners, pesticides

SepticSepticSystemSystem

A leaking septic system can causeserious pollution of streams. Have yourseptic tank pumped every 2 to 5 years,as needed. Never pour hazardous wastedown the drain.

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The Rivanna RegionalThe Rivanna RegionalStormwater EducationStormwater Education

PartnershipPartnership

www.www.rivannarivanna-stormwater.org-stormwater.org

You will find contact information forall the partners on our web site, as wellas information about stormwaterissues.

your backyard rain, runoff and - albemarle county, … rain, runoff and your backyard albemarle...

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