CITY OF DURHAM RAIN CATCHERS
City of Durham Rain Catchers Maintenance Guide
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Table of Contents
Topic Page Durham’s Watersheds and Water Quality 3 Rain Catchers Project Details 4 Downspout Disconnections 5 Cisterns 6 Fertilizers 7 Native Trees and Plants/Tree Maintenance 8-9 Rain Gardens 10 Rain Garden Maintenance 11 Rain Garden Species 12-15 Native Tree Species 16-17 Rain Garden Planting Plans 18-20 Maintenance Quick Guide 21 Native Plant Resources 22 References 23
A maintenance Quick Guide is on page 21 for your easy reference.
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Durham's Watersheds When rain falls on land, it runs downhill until it joins a creek, a riv- er, a lake, or the ocean. Sometimes this water, or stormwater, takes a shortcut through a storm drain. Storm drains lead straight to the nearest body of water. (Stormwater is not treated by water treatment plants.) As stormwater flows it can pick up chemicals from roadways, litter, topsoil, and other pollution that hurts our creeks. Rain that falls in Durham ends up in either Falls Lake or Jordan Lake, and eventually makes its way to the Atlantic Ocean. Any water pollution we create affects a lot of people. The land that drains into Ellerbe Creek is known as its watershed. The Ellerbe Creek watershed includes the area south of the Eno River watershed and north of the Durham Freeway (147). It in- cludes 9th Street, Bennett Place, Hillandale and Croasdaile Golf Courses, Duke’s East Campus, downtown, and Northgate Mall. Ellerbe Creek has the highest population density of Durham’s wa- tersheds. Water from Ellerbe Creek flows into Falls Lake. Then it flows into the Neuse River and then the Albemarle-Pamlico Sound before emptying into the ocean. Water Quality Stormwater Services staff tracks water quality at 5 sites in Ellerbe Creek. The health and cleanliness of the watershed is reported in Durham’s annual State of Our Streams report. Ellerbe Creek was last given a grade of 75 in 2012. This compares to a "C" letter grade in high school. This grade was given because of high nutrient levels that can cause too much algae to grow and high fecal coliform (a bacteria associated with raw sewage) levels. The State found that these water quality concerns keep Ellerbe Creek from its intended uses by people and wildlife. The State has added the creek to a list of impaired water bodies, also known as the 303(d) list. This means the City will need to take steps to find and reduce sources of pollution in the creek.
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The Rain Catchers Project
South Ellerbe Creek Subwatershed
In March, 2012, the City launched the Rain Catchers project to provide free rain gardens, native trees, and cisterns to residents in the South Ellerbe Creek subwatershed. Eligible homeowners received a mailing describing the project and instructions on how to participate. The City conducted site assessments of each applicant’s property and ranked the properties according to their potential to reduce the greatest amount of stormwater runoff.
The Rain Catchers project aims to reduce the rush of storm- water that flows to the creek when it rains. Water quality im- proves when stormwater slows down, spreads out, and soaks into the ground. Improving stream health is key to ensuring enough clean drinking water, recreation opportunities, and sus- tainable habitat for fish and wildlife.
City of Durham Page 5 Downspout Disconnection In Durham, rain enters storm drains and flows through pipes that are separate from the pipes that carry wastewater (toilet, shower, dishwasher, washing machines, and sink water). In a rain storm, large amounts of untreated stormwater flow directly into our creeks and streams.
Before driveways and sidewalks and roads were built, most rain water soaked directly into the ground. More sidewalks, roads, parking lots, and buildings mean less water can be absorbed. Rain water flows over these surfaces and carries away pollutants from our roofs, lawns, driveways and streets. The excess water carried away from our homes and streets also causes flooding of streams. Higher water levels in streams can loosen soils from stream banks, damage and uproot natural vegetation, and harm the organisms that live in the stream.
Gutters and downspouts that drain water from rooftops are of- ten connected directly to the stormwater system. Disconnecting our downspouts from the stormwater system allows stormwater to soak naturally into the ground. This recharges groundwater and improves the health of our local streams.
Image courtesy of: Mid-America Regional Council (MARC)
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Cisterns
The cistern installed by the Rain Catchers project is designed to hold 200 gallons of water. The water may be used for water- ing lawns and gardens, washing cars (with environmentally friendly, biodegradable soap!), etc.
Cistern Maintenance Clear debris from gutters at least once per year (more if you have overhanging trees). Check to make sure gutters are working properly at least once per year. Clear and debris from the top of your cistern four times per year (weekly during fall leaf season). Drain your cistern between rain events. If it stays full, it will not provide any water quality benefit. Check screening on top of the cistern monthly and repair as needed. Once a year, tip over the cistern and rinse it out with a hose. If algae or mosquitoes become a con- cern, add a capful of chlorine bleach. The small amount will not harm plants (but vinegar will).
Water Weight A cistern holding 200 gallons weighs more than 1,600 pounds!
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Fertilizer
Some of Durham’s streams and lakes Test your soil: have high levels of phosphorus and To get your free soil test nitrogen. Excess nutrients cause water kits and soil test contact: pollution problems like algae blooms, foul smelling and tasting water, and North Carolina low oxygen for fish and other wildlife. Coopera ve Extension Large amounts of these elements come Service directly from residential lawns and Durham County Center gardens. 721 Foster Street
Durham, NC 27701 Have your soil tested annually before you fertilize your soil. North 919‐560‐0525 Carolina Agriculture Extension Fax: 919‐560‐0530 Service Center offers free soil www.ces.ncsu.edu/ testing! It’s the best way to durham/ determine the need for lime, potassium, nitrogen and phosphorus. Use a phosphorus-free fertilizer unless your soil test indicates otherwise. Sweep up fertilizer from hard surfaces like the street and driveway. Store fertilizer in a sealed container.
Pet Waste carries pathogens such as Giardia, E. coli, Salmonella and Campylobacter. These bugs cause ill- ness in people, especially children and the elderly. Do your part to keep harmful bacteria out of our streams. You can help by always picking up after your pet when on walks and avoiding children's play areas. Even at home, picking up after your pet is important.
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Native Trees
Large, mature trees provide several stormwater management benefits. Above ground, the leaves, branches, and trunk of the tree intercept rainfall and slow the rate of water falling to the ground. The shade provided by mature trees also cools surfaces on the ground. As water flows over surfaces warmed by the sun it also increases in temperature, unnaturally increasing the temperatures of our creeks and streams. Underground, a mature tree’s well - developed root system soaks up groundwater and water evaporates when it is released by the tree’s leaves. The tree’s root system also acts as an anchor and reduces possible erosion of soils around it caused by running water.
Tree Maintenance Trees planted as part of the Rain Catchers Project will need to be watered regularly for the first one or two years. Remember the old gardener’s saying, “the first year it sleeps, the second year it creeps, the third year it leaps!”
Particularly in times of low rainfall or drought, a newly planted tree should be watered deeply once or twice a week. This will encourage roots to grow deeply instead of developing shallow roots at the soil surface searching for water.
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Native Plants
Native plants are naturally located in a particular habitat or region and have grown wild there since before the first European settlers came to America. Native plants are adapted to the local ecosys- tem, including soil, heat, humidity, and precipitation. Once estab- lished in your garden, they create a beautiful, drought-resistant, low-maintenance landscape. Birds, insects, and mammals rely on native plants for food and habitat. Bringing native plants into your garden can help urban wildlife survive and thrive.
Comparison of plant root depths
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Rain Gardens A rain garden is a shallow depression in the ground that captures and absorbs runoff, filtering the water before it enters our water- ways and reducing the powerful surge or water that rushes to creeks during a storm. Rain Catchers will typically redirect at least one downspout into your rain garden.
mulch layer: 3-4 inches
ponding depth: 6 inches
The Rain Catchers Project will select and use plants that are native to the Piedmont region of North Carolina. Native plants are well suited to our soils and climate. They also develop more extensive root systems than many ornamental plants. Deeper root systems help to anchor the soil around them and to survive prolonged peri- ods without rain. What about mosquitoes? Rain gardens should not hold water more than a day or two; they are designed to absorb runoff. Mosqui- toes require several days to hatch, so rain gardens do not generally breed mosquitoes when well- maintained. In fact, they attract birds and insects that can control mosquito populations!
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Rain Garden Maintenance (1) Water thoroughly, deeply, once weekly to encour- age deep roots and vigorous growth. Rain gardens require extra water during the first couple of seasons to be- come established. Use harvested rainwater whenever possi- ble! (2) Weed at least twice a month during growing sea- son. The garden also requires more weeding during estab- lishment. Weeds decrease considerably as the plants estab- lish. (3) Cut back stems and seed heads in early spring to allow room for new growth. Leaving them during winter provides wildlife cover and bird food. (4) Check tubing to make sure it is aimed properly so water enters the garden. Clear debris from tubing. (5) Clear leaves and debris from gutters at least once per year (more if you have overhanging trees). (6) Rearrange cobble stone where the tube discharges into the rain garden and at the rain garden overflow discharge, as needed. (7) Mulch your rain garden every 2 years with 3” inches of shredded hardwood mulch either after the first frost in fall or the last frost in spring. Mulch will help maintain moisture and reduce growth of unwanted weeds.
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Rain Garden Plants
Native Shrubs
Shrubs have woody stems that persist through the winter. Pruning can help limit growth and should be done while the
plant is dormant, typically from late fall to early spring.
Buttonbush (Cephalanthus occidentalis) Deciduous; 3-10 feet tall; flowers June-August; prune severely every winter to control size and promote flower production; flowers attract butterflies and bees.
Chokeberry (Photinia pyrifiolia) Deciduous; 5-6 feet tall;3-4 feet wide; late spring/early summer flow- ers; spreads by suckers; remove root suckers if you don’t want plant to spread into colonies.
Elderberry (Sambucus canadensis) 3-10 feet tall; fragrant, white flowers from May-July; attracts birds and butterflies. Annual pruning will con- siderably improve fruit yield. Can be pruned severely every few years to keep in bounds; spreads by suckers.
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Possumhaw (Viburnum nudum) Deciduous; 6-10 feet tall; 6-10 feet wide; white flowers on 3-5” cyme; hanging cluster of fruit starts green, then pink, rose, bluish, and purplish black.
Virginia sweetspire (Itea virginica) Semi-evergreen to evergreen; 3-6 feet tall; 4-6 feet wide; tiny white flowers on drooping 3-6” racemes; attracts butterflies; seeds eaten by birds.
Winterberry (Ilex verticillata) Deciduous; red berry-like drupes on female plants persist into winter; fruit attracts birds; tends to sucker and form clumps.
Highbush blueberry (Vaccinium corymbosum) Deciduous; 6-12 feet tall; fruit is an important food source for variety of wildlife; can be propagated by seeds or cuttings.
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Native Herbaceous Perennial Plants Herbaceous perennial plants die back each winter and return each spring. Dead stems may be cut back each year. Other- wise, minimal maintenance is required. Blue flag iris (Iris virginica) Blooms April-May
Bluestar (Amsonia tabernaemontana) Blooms in April
Butterflyweed (Asclepias tuberose) Blooms May-August
Cardinal flower (Lobelia cardinalis) Blooms July-October
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Culver’s root (Veronicastrum virginicum)
Little Bluestem (Schizachyrium scoparium) Light blue, gray, green foliage often turns orange/red in fall
New England aster (Symphyotrichum novae-angliae) Blooms September-October
Virginia bluebells (Mertensia virginica) Blooms March-June
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Native Trees
Ironwood (Carpinus caroliniana)
Fringetree (Chionanthus virginicus)
Redbud (Cercis canadensis)
Black Gum (Nyssa Sylvatica)
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Dogwood (Cornus florida)
Red Maple (Acer rubrum)
Willow Oak (Quercus phellos)
River Birch (Betula nigra)
White Oak (Quercus alba)
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Rain Garden Planting Plans
50 Square Feet, Part Shade
50 Square Feet, Sun
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Rain Garden Planting Plans
75 Square Feet, Part Shade
75 Square Feet, Sun
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Rain Garden Planting Plans
150 Square Feet, Part Shade
150 Square Feet, Sun
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Maintenance Quick Guide
Cisterns Drain/use water between rain events Clean gutters at least once per year Clear debris from screen as needed Repair screen as needed Rinse out once per year
Rain Gardens Water once per week for 2 years Weed at least twice per month Mulch every 2 years Clean gutters at least once per year Clear debris from tubing Rearrange cobble stone as needed
Trees Water once per week for 2 years
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Native Plant Resources
The North Carolina Botanical Garden: http://ncbg.unc.edu/native-southeastern-plants/
NCSU’s Going Native: Urban Landscaping with Native Plants: http://www.ncsu.edu/goingnative/howto/mapping/nplants/ index.php
The North Carolina Native Plant Society: http://www.ncwildflower.org/index.php/plants/listings/
Ladybird Johnson Wildflower Center’s NC Recommended Plant List: http://www.wildflower.org/collections/collection.php? collection=NC
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References
City of Durham, Stormwater Management http://durhamnc.gov/ich/op/pwd/storm/Pages/storm_ watersheds/fallslake.aspx
Justice, William S. Wild Flowers of North Carolina. Eds. C. Ritchie Bell and Anne H. Lindsey. Chapel Hill: University of North Carolina Press, 2005.
Kraus, Helen, and Anne Spafford. Rain Gardening in the South. Durham: Horse and Buggy Press, 2009.
North Carolina Cooperative Extension www.bae.ncsu.edu/topic/raingarden/Entire_handout.doc www.bae.ncsu.edu/topic/raingarden/ www.bae.ncsu.edu/stormwater www.ces.ncsu.edu/depts/hort/consumer/factsheets/
NC State University Urban Horticulture
USDA, NRCS. 2013. The PLANTS Database (http://plants.usda.gov, 24 January 2013). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Image Credits Buttonbush, Elderberry, and Bluestar images: Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA SCS. 1989. Midwest wetland flora: Field office illustrated guide to plant species. Midwest National Tech nical Center, Lincoln. New England Aster, Butterfly Weed, and Cover Photo: Amanda Willis. NC State University.
Contact Information
City of Durham Public Works Department Stormwater and GIS Services Division Phone: (919) 560-4326 Webpage: www.DurhamNC.gov/stormwater Project Manager: Laura Webb Smith, (919) 560-4326, ext. 30235, [email protected]