Porous paving materials save water

In our arid environment, wouldn't it be smart to capture the moisture that we do get from rain and snow and put it to good use? This is water that absorbs into the soil recharges groundwater reserves, water that runs off driveways, sidewalks and streets goes into storm drains and then into the river and downstream.

Around our homes and throughout our community, we install a lot of hard surfaces that repel water and make it run off our properties and into storm drains. Instead, we can use materials that will help hold onto that water and use it to replenish the soil moisture on our properties.

There are permeable construction materials for patios, walks, driveways and even streets. These products keep nuisance flooding down and can help keep our drinking water healthy.

Permeable pavement options vary. It is important to properly prepare the sub-base for the material you choose to use. The type of base material used and its depth greatly influence the amount of infiltration that occurs. They also affect the longevity of the paving or construction material. In colder climates, a thicker sub-base is needed. As with any product, proper maintenance must be regularly performed, following the manufacturers' recommendations.

Concrete block pavers interlock with each other, leaving spaces in between where water can soak in. These are good for driveways, streets and sidewalks. There are porous asphalts and concrete that also can work for driveways and walks. Plastic grid pavers are manufactured using recycled plastic, and are filled with gravel or soil and grass. They are not as strong as some other materials, but are flexible and more suited for use on uneven terrain. These can also be a good choice for driveways.

Setting a brick patio or walkway into sand without cementing it allows water to penetrate into the soil below. If designed with sub-surface drainage to planting areas in mind, trees and shrubs can benefit from the draining water. Decomposed granite walks and paths let water infiltrate, rather than run off, unused, down the street or gutter.

A landscape utilizing buffer zones at the edges of streets and sidewalks is another infiltration technique. The buffer zone is an area next to a lawn planted with very low-water-use plants that gathers any overspray from lawn sprinklers. Buffer areas to reduce water waste will be more widely seen in Carson City because of their adoption into the landscape code.

For detailed information on porous pavers, go to the Web site of University of Rhode Island Cooperative Extension, www.uri.edu, or contact me, 887-2252 or skellyj@unce.unr.edu, or your local University of Nevada Cooperative Extension office for more gardening information.

Check out many useful horticulture publications at www.unce.unr.edu. "Ask a Master Gardener" by e-mailing mastergardeners@unce.unr.edu.

• JoAnne Skelly is the Carson City / Storey County Extension educator for University of Nevada Cooperative Extension.