Assessing Your Yard’s Water Contributions

Stormwater from this property's roof and driveway discharges to a rain garden, where it will soak into the ground rather than running off and carrying pollutants to a ditch, stream or lake. Photo by Marcela Gara

Millions of people downhill from us drink the waters that are shed from our roofs, parking lots, streets and lawns.

As watershed residents, it is the responsibility of each of us to take care of the waters that land on our homes and yards. Rainfall and snow can contain dust, ash and pollen as well as nitrogen oxides, phosphorus and other pollutants which can fuel algae and plant growth in waterways. It can also harm living things, as in the case of mercury pollution from power plants and industries which burn coal.

So how can we assess our yards as important components of our watershed hydrological system? The Center for Watershed Protection has developed a Neighborhood Source Assessment methodology for evaluating the conditions of yards and neighborhoods and their ability to control pollution.

The first element to assess is the percentage of impervious surface on your property. Paved areas should be minimized so that precipitation can soak into your yard rather than run off and carry pollutants with it. Blacktop or concrete driveways are completely impervious, while gravel driveways are somewhat more permeable. Slatted decks underlain with gravel are preferable to concrete patios.

Turf, Soil Condition

Some suburban lawns can be almost as compacted and impervious as concrete. Is your yard soft with dense vegetative growth, or is it hard with sparse growth of grasses and other plants? If you pour water on it, does it easily soak in, or can it not penetrate the surface, resulting in it ponding and slowly soaking in or just flowing downhill? If your soil is hard, you may want to consider core aerating it and top dressing it with a humus-topsoil mixture and high quality grass seed for low maintenance turf. Bare soil areas should be planted with grass or native wildflower mixture and mulched to protect from erosion and to store soil moisture.

Chemical Treatment

Turf maintained with multiple chemical applications annually provides the opportunity for rainfall to carry away recently applied fertilizers or pesticides. In our region, measuring soil pH (acidity) and adding lime if necessary and one fall application of (phosphate-free) nitrogen fertilizer are the only chemicals most lawns require to maintain dense turf.

Grass Length

Lawns should optimally be mowed to 2§ inches to 3 inches or longer as tolerated. Root depth is proportional to leaf length – the longer the leaves, the healthier, deeper, more robust root systems. Longer leaves and stronger roots help grasses to out-compete invading weeds. Consider planting berms to hold native trees, shrubs and wildflowers, while helping to trap and infiltrate stormwater.

Tree Crown Coverage

The more of your yard that is shaded by trees, the better. Shade trees and evergreens can store up to the first quarter inch of a rainfall in leaves, needles and branches, thus delaying the saturation of soils and overland water flow from your yard. Tree roots are effective at absorbing nutrients and holding soils in place.

Pet Waste

Next, evaluate your yard for pet wastes, which are a concentrated source of phosphorus and a disease risk to children and local waterways. Pet wastes should be flushed down the toilet or buried away from wells, waterways and vegetable gardens at about 5 inches deep. One average weight (45-pound) dog produces urine and feces containing about 13 pounds of nitrogen and 2 pounds of phosphorus per year. One dog depositing its wastes near the lakeshore or on road shoulders can produce over a ton of algae per year. If you have a dog, please be a responsible scooper.

Drainage Patterns

Look at your yard’s stormwater drainage patterns. Downspouts should discharge to the lawn surface, dry wells, rain barrels or rain gardens at a safe distance from your foundation rather than discharge to driveways, road ditches, sanitary sewers or storm sewers. Driveways, when constructed or repaved, should be designed to drain to the yard or into the ground, not the street or storm sewer.

Determine if leaves, grass clippings or other vegetative matter or debris are a problem. Don’t allow leaves to pile up in the street or road ditch to be carried away with the next rainfall.

Waterfront Buffer

Lastly, if you have a lakefront or streamside yard, establish a low maintenance waterfront buffer area with native, deep-rooted vegetation to trap stormwater, filter nutrients from groundwater and prevent soil erosion. Natural waterfront buffers protect your property and provide important habitat for a variety of valuable creatures.

To obtain landscaping assistance or arrange for an informative assessment and presentation for your neighborhood association, contact the Chautauqua Watershed Conservancy at 664-2166 or info@chautauquawatershed.org.

The Chautauqua Watershed Conservancy is a local not-for-profit organization dedicated to preserving and enhancing the water quality, scenic beauty and ecological health of the lakes, streams, wetlands and watersheds of the Chautauqua region. For more information, call 664-2166 or visit chautauquawatershed.org or facebook.com/chautauquawatershed.