Why Soak Up the Rain?
Over 90% of the water pollution problems in New Hampshire are caused by the pollutants carried in stormwater runoff from the roads we travel, the buildings and parking lots we visit, and even the homes in which we live. Every single property has the potential to contribute to water pollution.
What You do in Your Backyard…
If your home has a roof, a lawn, or a driveway, chances are your property creates stormwater runoff. Property owners can play a role in improving water quality by soaking up stormwater runoff to prevent it from reaching nearby lakes, streams, and other waters. What you do in your own back yard can impact the entire watershed, including the health of lakes, streams, and other waters in your neighborhood and beyond.
What is Stormwater Runoff?
Stormwater runoff is water from rain or melting snow that doesn’t soak into the ground. Instead, it flows over the land surface, picks up pollutants in its path, and flows untreated into nearby bodies of water. Runoff can pollute lakes, ponds, streams, and coastal waters, making them unsafe for swimming and creating an unsafe habitat for fish and other animals, and can also contribute to flooding and erosion.
Impervious surfaces (e.g., roofs, driveways, walkways, decks, patios, compacted soils, other hard surfaces) change the way that water flows over and through the land. They prevent stormwater from soaking into the ground, which increases the volume of stormwater runoff that needs to be managed in our communities. Unmanaged stormwater runoff contributes to flooding, stream bank erosion, and reduced groundwater recharge.
Eroding soils can cause sediment to enter our waterways. This makes the water cloudy and reduces clarity. Fine sediment can clog the gills of fish and smother fish habitat. Sediment can fill in a lake or stream making it easier for plants, including invasive plants like purple loosestrife and exotic milfoil, to take root. Sediment tends to carry other pollutants with it including excess nutrients and metals.
Fertilizer, Pet Waste, Septic Systems
Fertilizers, pet waste, and septic systems can contribute excess nutrients that speed up plant and algae growth, including cyanobacteria, which can harm humans and animals and be a nuisance for swimming and boating. Nutrients can decrease the amount of oxygen in the water as plants die and decompose, leaving less oxygen available for fish and other organisms. They can also increase bacteria that can make swimmers sick and lead to beach closures. Bacteria not only pose a public health risk, but can cause an economic hardship for communities that rely on bathing beaches for tourism revenue.
Lawn Chemicals and Auto Chemicals
Lawn care chemicals and automotive chemicals can contribute potentially toxic contaminants that are harmful and potentially fatal to aquatic organisms, humans, and other animals.
Salt & Deicing Materials
Salt and other deicing materials used to treat roads include chloride, which increases the salinity of lakes. This stresses aquatic organisms that depend on freshwater habitats. As salinity increases, freshwater plants die off and salt-tolerant plants take over. Chloride can contaminate drinking water supplies, including private wells. Unlike other pollutants, there is no treatment for chloride pollution except for source control.
Increase in Water Temperature
Increases in water temperature can occur when stormwater runs over hot pavement or other surfaces with very little shade it heats up. This heats the runoff and can increase the temperature of streams and ponds. Many fish and aquatic species depend on the higher oxygen concentrations that cool water temperatures provide. The warmer water has less oxygen and makes it more difficult for fish to breathe.