Northwest Herald

From McHenry County Conservation District: Wetlands at work

They clean our drinking water. They hold and store rainwater. They create nurseries and food sources.

McHenry County is dependent on groundwater, extracted from both shallow and deep aquifer wells, as its sole source of drinking water. Protection of surface water resources and groundwater recharge areas are important to ensure a safe, sustainable and adequate supply of drinking water into the future. The health of these wetlands and their headwaters is critical to the health of an entire river network. McHenry County Conservation District protects over 3,000 acres of wetlands, rivers and streams throughout the county.

Small streams and their associated wetlands make up the majority of the county’s waters. These wetlands can be small spring-fed ponds or a depression in the ground that fills with water after every rain and overflows into the creek below. These water sources are the headwater streams, often unnamed and rarely appearing on maps. Although they may seem insignificant, they are in fact vital for recharging the groundwater supply as they feed into and create our large rivers. Kishwaukee Headwaters Conservation Area in Woodstock is one example where, depending upon the time of year and amount of precipitation, the area can be visibly very dry or very wet.

Wetlands provide numerous beneficial functions on the landscape to protect and improve water quality, as well as maintain surface water flow during dry periods. They also absorb and slow floodwaters, helping to alleviate property damage and loss. Although a small wetland may not seem to store much water, a network of many small wetlands can store an enormous amount of water, whereby one acre of wetland can store up to 1.5 million gallons of floodwater.

Our wetlands, headwaters and small streams play a critical role to the health of an entire river network. They act as natural water cleaners as they absorb and filter nutrients such as nitrogen and phosphorus and other pollutants from flowing downstream. After being slowed by a wetland, nutrients from fertilizer application, manure, or leaking septic tanks, which could be harmful to the natural environment, are dissolved in the water and absorbed by plant roots and microorganisms in the soil or stick to soil particles. This natural filtration process removes much of the water’s pollutant load by the time it leaves a wetland. Without the wetland filtration, a build-up of excess nutrients can occur downstream and cause algal blooms or dead zones.

The next time you visit a wetland, note which plants and animals are living or visiting the habitat. Often called “nurseries of life,” wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. In fact, up to one-half of North American bird species nest or feed in wetlands and 31% of the country’s plant species thrive in healthy, functioning wetlands. While wetlands are best known for being home to water lilies, turtles and frogs, they also provide important habitat for a wide range of species including salamanders, ducks, herons, fish, mussels, insects, snails and other invertebrates.

See our wetlands at work for yourself by visiting some of the Conservation District’s varied wetlands, including those at Boger Bog in Bull Valley, Glacial Park in Ringwood, Lyons Prairie and Marsh in Cary, Lake in the Hills Fen in Lake in the Hills, and at Exner Marsh, Kishwaukee Headwaters and Pleasant Valley in Woodstock.