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- Bu səhifədəki naviqasiya:
- | Re-routing of Downspouts to Direct Roof Run-off.
- | Rain Barrels
- | Rain Gardens
- Backyard Wetlands
- | French Drains
- | Native Landscaping and Tree Planting
| Permeable Paving What is Permeable Paving? -Permeable pavement is any paving material that allows rainwater to percolate through the pavement and infiltrate the soil. -Permeable paving comes in various forms: pervious concrete, pervious asphalt, and concrete pavers are some of the most popular materials. -Permeable paving systems require a washed stone base, which aids in adding runoff storage volume as well as structural support. -Permeable paving must be installed correctly and to manufacturer’s specifications in order to be effective and requires Town Engineer approval.
-The concrete industry has data on the long term performance and cost-benefit of using pervious pavement systems. -Permeable pavement has been used successfully in many locations in North Carolina and Nags Head.
Helpful Hints Permeable pavements can be used in conjunction with underground detention or rainwater harvesting systems to gain additional stormwater benefits. -There are thousands of paver and material options which provide many aesthetic choices. -Contact your local contractor for more information. Where to Start
-Pervious pavement systems should be sited on generally flat areas. -Edge restraints are recommended. -Obtain a soil test to determine infiltration characteristics before installing pavements because an under drain might be needed. -Only install permeable systems where the seasonal high water depth is adequate to permit the system to drain completely.
-Consider using a thicker washed stone base to increase storage capacity and further reduce runoff volumes.
-Systems should be checked regularly for proper drainage. -Important to keep surface clean of debris which can clog porous material. If infiltration rate decreases, clean the surface layer. -If system still loses infiltration capabilities, contact an engineer or qualified contractor. -Potholes, cracks, or damaged pavers should be repaired or replaced. References and Resources Carolina Ready-Mix Concrete Association: www.crmca.com Pervious Pavement: www.perviouspavement.org/ Concrete Network: www.concretenetwork.com/pervious/ Low Impact Development Center: www.lowimpactdevelopment.org NC DWQ BMP Manual, Permeable Pavement: http://portal.ncdenr.org/web/lr/bmp-manual 
 
| Re-routing of Downspouts to Direct Roof Run-off. Why Re-route Downspouts? -Downspouts directed to driveways, sidewalks or parking lots increase the amount of polluted runoff by an average of 50 percent or more. -Instead of contributing to stormwater pollution, you can put rain water to use by redirecting it to vegetated areas or yards. -Downspouts used in connection with rain barrels or cisterns can also collect rain water for use during dry periods. -Redirecting roof runoff is cost effective, easy to do and virtually maintenance free.
During the summer months, nearly 40 percent of household water is used for lawn and garden maintenance. Benefits
Helpful Hints Re-route your downspout with these few simple techniques:
References and Resources Mid-America Regional Council: www.marc.org/environment/water North Carolina Coastal Federation: www.nccoast.org City of Portland Stormwater Solutions Handbook: www.portlandonline.com DC River Smart Homes: www.ddoe.dc.gov; search downspout disconnection
Cisterns are large water harvesting systems which collect rain water and store it for future use. In contrast to a rain barrel, which stores only a small volume of water, cisterns are sized to capture larger volumes of water and can be installed above or below ground. This water can then be reused for irrigation, industrial processes, and/or commercial reuse. Did You Know? -For every inch of rain that falls on a 1,200 square foot area, approximately 750 gallons of stormwater runoff is produced. -For high water consumption users, cisterns can be a financially profitable investment, paying for themselves by reducing or even eliminating water bills for non-potable uses.
Helpful Hints -Check with Town Building Inspector before construction. -Cisterns are often visible “green” elements of a property and many aesthetic options are available. -Low cost filters are available to prevent clogging and reduce maintenance needs. -Computerized water management systems can optimize performance. -A cistern system that minimizes sunlight penetration can help prevent bacteria and mosquito growth. 
How to Size and Install Your Cistern
-Look for ways to connect multiple downspouts into a system. -For especially large systems, water can be stored underground in vaults or other engineered systems.
-Heavy construction equipment is often required, but most commercial contractors have the equipment which would be needed. -There are a number of specialized rainwater harvesting contractors who offer comprehensive design and installation services.
-Cisterns can be used on existing development or new construction. -A full cistern is heavy and may require additional support, such as a concrete or gravel pad. -If rainwater is to be used inside a building for non-potable uses, dual plumbing systems will be required.
| Rain Barrels What is a Rain Barrel? A rain barrel is a container that collects and stores rainwater from your roof that would otherwise be lost to runoff. Rain barrels come in all shapes and sizes. They typically include the drum, a vinyl hose, PVC couplings and screen to keep debris and insects out. A rain barrel can sit conveniently under any residential gutter downspout. Did you know? -One quarter inch (¼”) of rain produces enough runoff to fill a typical rain barrel hooked up to one downspout. -If you and your neighbors all added just one rain barrel per residence, it would have a significant impact on flooding and pollution in your community. -One 55 gallon rain barrel holds a full week’s worth of water for a 10’x10’ garden. -Rain barrels come in a variety of sizes, colors and designs and are available for purchase locally and on-line.
Helpful hints -Always keep the lid to your barrel tightly secured to avoid any accidents involving children or animals. -Do not consume water collected in barrel!
-Most rain barrels are easy to install; however, actual installation methods vary depending on the type of rain barrel. Installation typically involves disconnecting your downspout, cutting off a portion of the downspout and redirecting it into the top of the barrel. -Most rain barrels have an overflow pipe that redirects the rainwater back into the downspout or onto your lawn or other surface in the event the barrel is full. -Some barrels come with safety features, spigots, mosquito proofing, and even water filters. -Some barrels come with connection attachments so that multiple barrels can work together. Care -Use water between rains, or empty prior to storms. -Annually empty and wash out barrel. -Clean your gutters regularly to prevent debris. -If you see algae, add one cap of chlorine bleach to a full barrel of water; this small amount won’t hurt plants. References and Resources NC Cooperative Extension: www.ces.ncsu.edu ; search rainwater NC State University: www.bae.ncsu.edu/topic/ ; click water harvesting NC Coastal Federation: www.nccoast.org ; click low impact development 
| Rain Gardens 
What is a Rain Garden? Rain Gardens are small, shallow, vegetated areas where rainwater collects during storms. Rain gardens are typically 4-8 inches lower than the surrounding lawn and act as a bowl that collects runoff. The plants and soil soak up the rain water before it becomes polluted runoff. Did You Know? -Rain gardens can reduce runoff by 90% or more. -Rain gardens enhance yards and landscapes and can host a variety of plants.
Helpful Hints -Observe water flow patterns during rains to determine potential areas for rain gardens. -Use native plants for lower maintenance. -Rain gardens may not be suitable in areas with standing water. (See Backyard Wetland fact sheet). -Make sure water from rooftops or driveways is directed into the garden.
Build and Plant
-Select an area to capture and absorb runoff based on how water flows across your land. -Site the garden at least 10’ from your house, and 25’ from wells or septic fields. -Make sure the soil will drain. -Plant flowers, shrubs, grasses or even turf.
-A small rain garden can be built by hand in a weekend. Contact Town staff or a local contractor for additional assistance if needed.
-Heavy double or triple shredded hardwood mulch works best because it won’t float away. It also helps retain moisture for the plants. -Choose native vegetation when possible.
-Periodically water garden until established. -Mulch annually. References and Resources See the “Native Landscaping and Tree Planting” fact sheet for more help, or contact your local nursery or Dare County Cooperative Extension for more assistance. NC State University Rain Garden Guide: www.bae.ncsu.edu; search rain gardens NC Cooperative Extension: http://www.darenc.com/soilwater/raingrdn.asp NC Coastal Federation: www.nccoast.org; search low impact development 
| Backyard Wetlands 
What is a backyard wetland? Backyard wetlands are depressed wet areas that are planted with native wetland plants. They are well suited for areas that are usually wet for several days following a rain event. Backyard wetlands are designed to capture and treat stormwater similar to a rain garden but in locations with high-water tables and soggy soils. Did you know? -Man-made backyard wetland gardens can provide many of the same benefits of natural wetlands. -A wetland will temporarily store, filter, and clean runoff water from your roof and lawn. -It will provide habitat for butterflies and bees, salamanders, toads, frogs, and birds. Benefits
Helpful Hints -Locate the backyard wetland where it is not likely to attract unattended children. -Check local safety ordinances and building ordinances for restrictions and permit requirements. -Check soil maps to locate wetlands appropriately. Build and Construct -Choose areas of your lawn that include naturally occurring wet spots for your wetland. -Locate wetland at least 10 feet from any foundation. -Setback at least 25’ from septic fields and well heads. -Ponding depth of wetland should be no more than 9”. -Refer to Common Wetland Plants of North Carolina to choose native plants to use in your backyard wetland. References and Resources Natural Resources Conservation Service: http://www.nrcs.usda.gov/wps/portal/nrcs/site/national/home/ NCSU Urban Waterways – Designing Stormwater Wetlands for Small Watersheds: http://www.bae.ncsu.edu/stormwater/PublicationFiles/SWwetlands2000.pdf Common Wetland Plants of North Carolina, produced by the N.C. Department of Environment and Natural Resources, Division of Water Quality: http://portal.ncdenr.org/c/document_library/get_file?uuid=d0f7bb32-5585-4acf-a399-8d484488d234&groupId=38364 Division of Soil and Water Conservation Community Conservation Assistance Program: http://www.ncagr.gov/SWC/costshareprograms/CCAP/index.html 
| French Drains What is a French Drain? A French drain is a trench covered in washed stone or other approved media that diverts surface and groundwater away from a specific area. French drains are a commonly used drainage system, primarily applied as a preventative measure against surface and ground water penetrating and/or damaging foundations. French drains are also used behind retaining walls to relieve ground water pressure or strategically placed in flat areas to drain standing water from the yard. Alternatively, the French drain technique may be used to capture, collect, and convey runoff to a secondary stormwater BMP device when site constraints may not permit adequate width for a vegetative swale. Benefits 
Build and Construct -Choose an appropriate location based upon whether the application will capture runoff by way of sheet flow or conveyance, (from a gutter system downspout) . -Can be located adjacent to a building foundation. Locate at least 5 feet horizontally from any septic system.
-Excavate trench, install geotextile fabric by lining inside ditch bottom and walls, and install perforated pipe, slope at 1 in. per 10’ of length. - Backfill trench with clean washed gravel.
Planting trees can help reduce stormwater by intercepting it and allowing it to evaporate, as well as dissipating the energy of runoff. They also provide shade, which keeps surface temperatures lower and facilitate stormwater infiltration. Did you know? -Native trees/plants are hardy and suited to our soils and climate and are part of our coastal heritage. -Require little care once established as compared to non-natives. -Absorb and slow the flow of stormwater runoff. -Prevent erosion and increase soil permeability. Benefits
Helpful Hints -Direct runoff to native landscaping or rain garden to capture stormwater and create beautiful habitats. -Design yard features that include depressions with native plants.
Build and Plant Use the landscape to help keep rain water on site. Plant trees that maximize interception of rain. Plant native trees with higher growth rates. References and Resources www.ncsu.edu/goingnative/howto/index.html NC Coastal Federation: www.nccoast.org; search native plants Water Forestry Guide: www.forestsforwatersheds.org Local Nurseries and Landscape Professionals http://www.naturesharmonynursery.com/ | 3. Siting Considerations Related to Separation Distances
Raingardens (Dry/ with liner): 10 ft.* Raingardens (Wet): 50 ft.*
*Horizontal distances as prescribed by the Dare County Department of Environmental Health **As per 15A NCAC 18A Laws & Rules Regulating Sewage Treatment & Disposal Systems Single-Family Residential or Duplex Development on individual lots with alternative septic systems
General Standards for Commercial or Residential Subdivisions • As per 15A NCAC 18A.1900 Laws & Rules Regulating Sewage Treatment & Disposal Systems.
Required separation distance from wetlands:
Required separation distance of fill slopes from property boundaries:
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