Being water wise means making lifestyle choices in addition to the way we carve out our home environments. Whether you’re building a new home or landscape, renovating an existing one, or making simple changes to how you use water, it’s possible to conserve and protect our precious water resources. Through thoughtful site planning, architecture, landscape architecture, and garden design, we can reduce runoff, pollution, and water use.
The increase of impervious surfaces from building-related development has caused stormwater runoff to become a major problem that threatens the quality of our lakes and waterways and increases flooding risk to our homes and businesses. Can we realistically stem this tide? From simple homemade solutions all the way to engineered systems, we can capture, harvest, and infiltrate rainwater. Common methods include rain gardens, rain barrels and cisterns, permeable pavement, and green roofs.
In its broadest sense, a rain garden is the use of living plant material in a specific area in order to collect and absorb surface water runoff. Rain gardens can be as simple as slight depressions in the lawn to collect water or gardens planted near downspouts and as complex as bioretention basins that are designed to cleanse and infiltrate larger quantities of water.
Permeable and semipermeable paved surfaces, such as turf stone, gravel, and pavers, can be both aesthetic and functional for driveways, parking areas, walks, and patios. Permeable paving has greater water infiltration capacity and more surface friction—which slows runoff—than traditional asphalt or concrete. In addition to assisting in overall stormwater management, permeable paving is available in a wide variety of colors, textures, and styles that add interest and beauty to the landscape.
Green roofs can be used to control runoff at its source and may vary from simple groundcover carpets of sedum or grass to complex, layered gardens. Other benefits of green roofs often include longer roof life, decreased building energy costs, and sound insulation. A simple green roof can consist of a waterproofing and drainage mat, three to five inches of growing media, and, because they are not grounded in the earth, plants that are able to withstand extreme climate change. More elaborate rooftop gardens can offer additional outdoor living space if they are designed to hold live loads, heavier plant materials, and soil and water.
You can decrease your water usage by harvesting rainwater and reusing gray water. Rain barrels and cisterns have been used to harvest rainwater for thousands of years and were standard features in many older homes. Today, there are a wide variety of storage tanks and pumping systems designed to collect rainwater from rooftops and temporarily store the rainwater for reuse in nonconsumable ways. Cisterns vary in size from rain barrels that hold under a hundred of gallons of water to storage cisterns with the capacity to hold thousands of gallons. Rain barrels, the simplest form of cisterns, are readily available and easy for individuals to install.
Your landscapes can be designed to thrive without the use of irrigation by choosing plants appropriate for your site conditions. Xerophytic landscapes are those designed for little or no irrigation. They usually do not include lawns, but decreasing your total lawn area, replacing lawn with ground covers, and letting your lawn go dormant in times of heat and drought will reduce your water use.
If you do irrigate, make sure that the water is going where it’s intended, only when needed, and avoid overirrigating to reduce waste and runoff. Plants that get a good start in life are better able to adapt to changes and weather extremes. Watering thoroughly during garden establishment encourages deeper rooting for better drought tolerance, and adding organic matter helps to reduce soil compaction to allow for better infiltration and root growth. Consciously selecting plants suited to the environmental conditions of your landscape and caring for them during establishment can cut the need for irrigation and pesticides.
We can all incorporate individual techniques that decrease the amount of runoff in our own landscapes and improve the water quality of our lakes, rivers, and groundwater. We can design beautiful rain gardens and green roofs that slow, infiltrate, and cleanse runoff, and water storage systems that can collect, store, and make available for other use the water that falls onto our rooftops and paved surfaces. We can choose plantings that limit the need for supplemental irrigation. By combining these techniques when possible, we can create complex, enjoyable, and interesting outdoor spaces that add value to our daily lives and benefit our communities and the natural resources we depend upon.
Joan W. Ziegler is a horticulturist and garden designer and winner of the 2015 Perennial Plant Association Merit Award for Residential Landscape at ZDA, Inc. Landscape Architecture, 4797 Capitol View Road, Middleton. Call (608) 831-5098 or visit zdainc.com .