Outdoor Water Conservation & Sustainable Landscaping Methods

What It Is

Maintaining a beautiful landscape nearly always requires some water. Outdoor water conservation includes best practices that reduce the overall amount of water needed to maintain landscapes.

Additionally, when it rains, water hits surfaces like roofs, streets, and sidewalks. Because these surfaces cannot absorb water, the rain runs off into storm drains and nearby water sources (e.g., oceans, lakes, streams), carrying debris, chemicals, and other pollutants along with it.

Reducing stormwater runoff improves water quality because it prevents pollutants from reaching our oceans, lakes, and streams and takes stress off of sewer systems. Methods for handling runoff include

• Disposing of chemicals properly
• Collecting rainfall in barrels
• Planting rain gardens
• Planting riparian buffers
• Using pervious (i.e., porous) concrete

Why It Matters

Landscaping can be a needless water hog, driving up water bills. Due to the number of droughts that are common these days, water intensive landscaping can be problematic and costly. Environmental landscaping, or xeriscaping, reduces the amount of water you need to irrigate your lawn and plants.

With regard to runoff:

Runoff hurts people.

Stormwater threatens people’s health. “Polluted stormwater often affects drinking water sources. This [affects our] health and increases drinking water treatment costs.”[1] Pollutants in runoff can also wash pathogens into swimming areas, putting swimmers at risk. Reducing runoff improves water quality, which reduces these health hazards.

Runoff hurts animals and the environment.

Runoff carries sediment and excess nutrients into water sources, which can kill aquatic plants and animals. Sediment clouds the water, making it hard for aquatic plants to grow. Excess nutrients cause algae blooms, which leech oxygen from the water when they decompose, further threatening aquatic life.[2]

Reducing runoff protects property and increases value.

Reducing runoff prevents flooding and increases property value. Stormwater management keeps rainwater from flooding streets, sewers, and water sources. Plus, many of the best management practices for reducing runoff involve landscaping, which increases property value (See the “Going Further” section for more information).

Getting Started

To reduce water use in landscaping

• Use mulch, which helps absorb rainwater
• Promote healthy soil by amending it with compost
• Reduce grass
• Select hardy, drought-tolerant plants

To reduce runoff and improve water quality, your business can

• Dispose of hazardous chemicals properly
• Check your septic tank
• Use rain barrels or cisterns
• Practice environmental landscaping

Proper disposal of chemicals and sewage can improve the water quality of your local water sources. If your business deals with hazardous chemicals (e.g., paints, pesticides, cleaning products), see if your city offers hazardous waste collection. If not, dispose of them in the trash rather than dumping them outside or down the drain. This will help identify any leaks and prevent groundwater contamination.

You can also reduce runoff with rain barrels, cisterns, and environmental landscaping. Rain barrels and cisterns (See “Glossary”) capture rainwater, which you can then use for landscaping or for other non-potable water usage, such as flushing toilets. Other environmentally-friendly landscaping practices include

• Reducing use of pesticides and fertilizers
• Mulching, which helps absorb rainwater[3]

Rain barrels, cisterns, and environmental landscaping will reduce runoff, as well as your water bill. Check out BeWaterSmart.org for more information on rain barrels and cisterns. For more on environmental landscaping, visit EnviroLandscaping.org.

Going Further

To further reduce water use in landscaping, consider installing drip irrigation.

Drip Irrigation

Drip irrigation, a more involved method of environmental landscaping, helps reduce the amount of water you use when watering trees, grass, and shrubs.  It slowly delivers water to the topsoil or directly to the roots of the plants, using much less water than a hose or watering can.  This kind of irrigation is particularly good for arid regions.  Watch this video to learn more about it.

To take stormwater management to the next level, your business can

• Install a green roof
• Plant a rain garden, riparian buffer, or vegetated swale
• Switch to pervious pavement

1.) Green roofs

A green roof, or rooftop garden, is a vegetative layer grown on a rooftop. In addition to improving stormwater management and water quality, green roofs

• Reduce energy use
• Retain air pollution and greenhouse gases
• Improve human health and comfort[4]

Check out the EPA’s short article on green roofs to learn more.

2.) Rain Garden, Riparian Buffer, or Vegetated Swale

Rain Garden

Rain gardens are built in low-lying areas or depressions with special soils that facilitate retaining water, allowing runoff to seep into the water table rather than rush into storm drains or water sources. When planting a rain garden, use hardy native plants that can withstand drought and flooding (See a list of examples here). This will help your rain garden better absorb and filter stormwater runoff. Check out eHow.com to learn how to plant your own rain garden.

Riparian Buffer

Riparian buffers, also known as a riparian corridors or forested buffers, protect streams, rivers, or other bodies of water from runoff. These buffers, which are made up of trees, shrubs, and other local plants

• Slow down and absorb rainwater
• Trap and remove pollutants
• Provide shade
• Prevent streambank erosion[5]

Click here for instructions on how to plant a riparian buffer.

Vegetated Swale

A swale is a shallow channel or ditch covered with hardy grass (e.g., reed canary grass, red fescue), which absorbs rainwater, snowmelt, and irrigation runoff. Vegetated swales cannot absorb as much water as gardens or buffers, making them better suited for areas with less rainfall.[6] Check out the EPA’s Vegetated Swale Fact Sheet for more information.

3.) Pervious Pavement

Pervious, or porous, pavement is “asphalt with some particles left out of the mix. Small holes remain in the pavement, allowing water to pass through.”[7] This lets stormwater filter through the pavement instead of running off into nearby water sources. Check out PerviousConcrete.org to learn more.

Case Study

The Morris Arboretum in Pennsylvania used porous pavement in its parking lot. Bob Gutowski, Director of Public Affairs at the arboretum, notes that the porous pavement prevents flooding and reduces black ice. Watch a short video on the case study here.

Resources for More Information

Videos:

• Freno Rain Garden- Stormwater Demo by Dave Mudd demonstrates what a rain garden can do.
• StormwaterPA: Riparian Buffer Restoration by GreenTreks talks about reducing runoff with riparian buffers.
• Stormwater Pollution Prevention for Restaurants by the Town of Chapel Hill
• Stormwater Runoff (5 short videos) compiled by ProtectOurSound

Links:

• After the Storm by the EPA is a good primer on stormwater runoff.
• Drought Tolerant Shrubs by NC State’s Horticultural Science Department provides a detailed list of drought tolerant plants.
• Household Hazardous Waste by the EPA gives more information on disposing of hazardous products.
• Stormwater Manager’s Resource Center provides a library of resources.
• StormwaterPA shares practices, case studies, and benefits of stormwater management.
• Sustainable Cities Institute offers information, tips, and case studies about stormwater management.

Conclusion

Environmental landscaping reduces water usage, which saves money and reduces headaches during times of drought. Reducing runoff improves water quality, which benefits people, animals, the environment. It also helps your local water treatment facility, which can help reduce your local tax burden. Techniques like proper waste disposal, environmental landscaping, planting rain gardens, and switching to pervious pavement help your business reduce runoff and its water bill.

Glossary of Related Terms

Cistern: A cistern is like a large underground rain barrel. It collects rainwater, which you can later use for landscaping.

Impervious Surface: An impervious surface cannot absorb rainwater. Examples include roofs, parking lots, sidewalks, and compacted soil.

Rain Barrel: Rain barrels capture water for landscaping use, lowering water bills.

Rain Garden: This is an area planted with native shrubs, wildflowers, and grasses that collect stormwater runoff from paved surfaces, allowing it to soak into the ground. Using native plants minimizes the amount of time, energy, and fertilizer you need to sustain your rain garden.

Riparian Buffer: Situated next to a stream or river, a riparian buffer is made up of trees, shrubs, and other plants. The plants in the buffer absorb and filter stormwater, which helps support wildlife, prevent bank erosion, and protect water quality.

Runoff: Impervious surfaces cannot absorb rainwater, so it runs off into storm drains instead. Runoff carries various pollutants, such as sediments, fertilizers, and pesticides.

Swale: A swale is a shallow channel or ditch that helps soak up rainwater, snowmelt, or irrigation runoff. Unlike riparian buffers, swales are flanked with hardy grasses instead of trees and shrubs.

Water-Efficient Landscaping (Xeriscaping): A method of landscaping or gardening that uses drought-tolerant plants, which reduce the need for irrigation.  For more information on water-efficient landscaping, check out EarthEasy.com.

Water Quality: The physical, chemical, and biological makeup of water. Good quality water supports a variety of life. Bad quality water may contain pollutants such as

• Pesticides
• Fertilizers
• Herbicides
• Fluids from vehicles
• Harmful bacteria
• Sediments

[1] Quote retrieved from “After the Storm” on the EPA website, http://water.epa.gov/action/weatherchannel/stormwater.cfm

[2] Information retrieved from “After the Storm” on the EPA website, http://water.epa.gov/action/weatherchannel/stormwater.cfm

[3] List retrieved from “Why Conservation Landscaping: Principles and Steps” on EnviroLandscaping.org, http://www.envirolandscaping.org/conservation.htm

[4] Information retrieved from “Green Roofs” on the EPA website, http://www.epa.gov/heatisld/mitigation/greenroofs.htm

[5] List retrieved from “Profile: Riparian Buffer Restoration” on the StormwaterPA website, http://www.stormwaterpa.org/riparian-buffer.html

[6] Information retrieved from “Storm Water Technology Fact Sheet: Vegetated Swales” by the EPA, http://water.epa.gov/scitech/wastetech/upload/2002_06_28_mtb_vegswale.pdf

[7] Information retrieved from a video, “Managing Stormwater: Porous Pavement,” by StormwaterPA, http://www.stormwaterpa.org/pervious-pavement.html