In our increasingly urban landscape, small ponds are scattered across neighborhoods and cities. At first glance, they may appear as natural ponds or wetlands providing habitat for wildlife such as turtles, frogs, and waterfowl. Native wildflowers and plants can surround them. To new homeowners, they may even be advertised as "waterfront" or a landscaping feature. However, these ponds are not just ponds but a stormwater treatment practice.

What to look for 

Taking a closer look, you may notice these ponds are located near large shopping centers, in neighborhoods, community parks, school fields, and along parking lots and roadways. They have steeper banks, and water levels may rise and fall frequently. Or at times they might simply be a muddy hole. During the summer the water can look greener and have a distinct smell compared to the lakes or larger waterbodies nearby. These are all indicators of stormwater ponds.

Purpose of stormwater ponds

Stormwater ponds serve an important purpose. They collect water that runs off streets, sidewalks, rooftops, lawns, fields, and parking lots during rainstorms or snow melts. This runoff carries high levels of pollutants such as nutrients, oils, bacteria, sediment, and heavy metals, which can cause poor water quality and human health hazards if allowed to reach our lakes, rivers, and wetlands. Stormwater ponds collect and hold this runoff water temporarily, capturing pollutants and allowing them to settle out. Thus, preventing pollutants from reaching lakes and rivers. These ponds also reduce flood risk by holding the water and allowing it to slowly sink into the soil.

Some ponds are reuse ponds

While cities, schools, businesses, and housing developments install stormwater ponds to meet regulations and protect our lakes, rivers, and wetlands from pollutants, they sometimes install a different type of stormwater pond known as a reuse system.

Stormwater reuse systems look similar to stormwater ponds, but the reuse pond's water level may rise and fall frequently, and pipes or tubing may be visible during low water levels. This change in water level is because the pond’s water is being pumped out and used to irrigate lawns, parks, and sports fields rather than using potable city water.

Preserving drinking water and saving money

Reusing stormwater reduces irrigation costs for residents and businesses and helps protect the city's potable drinking water supply, especially during droughts. This is important for communities like Carver County, whose towns and residents rely on groundwater for their water supply. In 2024, stormwater reuse systems across Carver County used around 42,625,141 gallons of reuse water instead of potable water for irrigation, totaling a cost savings of approximately $ 314,114.84.

Furthermore, these reuse systems helped prevent an estimated 88.85 lbs. of phosphorus and 30,554 lbs. of total suspended solids (sediment), which reduce water quality and fuel algae blooms, from reaching our lakes, rivers, and wetlands.