Water Protection from Forest to Faucet

Katie Huston for TEI

Ask Paul Barten how much we spend in the U.S. purifying water each year, and he’ll tell you, “More than we need to spend.” That’s why Barten, an associate professor in the department of Natural Resources and Conservation, and his students are developing new mapping methods to protect public water supplies from pollution associated with land use. “If you focus on avoiding and preventing pollution, you can substantially reduce water treatment costs,” he says.

According to Barten, most of the total pollutant load typically comes from a small proportion of the watershed. Damage often comes from sites such as inappropriately managed farms and forests or poor stormwater management in suburban and urban areas.

To combat this, Barten and his students have developed add-ons to standard geographic information system (GIS) software to accurately identify areas with a high potential for sediment and nutrient loading.

“If, for example, there’s a truck stop parking lot that spikes relatively clean water with half the periodic table and undoes all the good work that you’ve done upstream, you really need to identify this site and quickly begin the pollution control process,” Barten says.

Even nutrients like nitrogen and phosphorus can be pollutants when they reach the reservoirs. For example, phosphorus can lead to algal blooms and associated taste and odor problems.
Barten and his students assemble as much data as possible about large, diverse watersheds, including topography, climate data, soil and geologic properties, land use data and stream flows, to create maps and models that will help identify critical areas for water quality protection or improvement. “There are few surprises once you unravel all the combinations and permutations of things like topography, soil type and nature of the land use,” he says.

The maps use color scales and other intuitive graphics to make the science easily accessible, even for people without specialized training. “We could do much more sophisticated modeling first, but then if no one understands the output it can be counterproductive,” Barten says.

Once problem areas are identified and confirmed in the field, several things can be done. It helps alleviate many pollution problems when stormwater is diverted into the soil and deeper groundwater systems before entering the water supply. Subsurface flow is subject to a filtering process as it moves through soil, when trees, other plants, and microbes can use some or all of the dissolved nutrients.

For example, if stormwater is flowing from a parking lot straight into a catch basin, then a stream, the site can be re-contoured to direct water into a stormwater detention basin or created wetland. Water filters through the bottom, leaving the sediment and most of the nutrients behind.

Consistent with his focus on prevention, Barten also suggests managing forests, designing residential development, and operating farms with an eye to reducing water pollution, including streamside management zones with enough forest vegetation to protect water sources.

“If you can stop the soil particle in the field, forest, or lawn where it belongs, you can prevent many costly problems,” Barten says.

Making things happen, though, takes a coalition of state and federal agencies, water utilities, environmental groups and concerned citizens. Barten cooperates with state and federal agencies, The Nature Conservancy, the Trust for Public Land, water utilities, public health groups, and environmental groups with interests in conservation.

To date, Barten has mapped areas outside Atlanta, GA; around Baltimore, MD.; developed areas in New Jersey; and the Nashua river watershed on the Massachusetts-New Hampshire border. He’s currently working with Portland, Maine; Hartford, CT.; and closer to home, around the Westfield River watershed, which includes the Springfield, Westfield, and Holyoke reservoirs and many small community water supplies. In addition, he co-authored a book with Avril de la Cretaz entitled “Land Use Effects on Streamflow and Water Quality in the Northeastern United States” that was published in 2007.

The benefits of Barten’s work are manifold. “There are major social and economic benefits,” he says. “The money that you don’t spend on water treatment because you’ve done a good job of managing pollution sources is money you can invest in schools and healthcare and all the other things that society needs.”
Improving the water supply also benefits aquatic ecosystems and biodiversity, and even improves recreational opportunities and visual appeal of streams, ponds, and lakes.

Water supply is, or at least should be, of greater concern today than ever. A hundred years ago, Barten says, people used about five gallons of water per day. Today, household water use adds up to about 70 gallons per person per day. There is about twice as much forest in New England today than in 1900. But the number of people (all using more water) has doubled or tripled, making every acre of forest five to 20 times more important than it was a century ago.

However, because people tend to think of water as a renewable resource, Barten says, it is often taken for granted.

“People are lulled to sleep by this notion that water is renewable so it will endlessly regenerate and cleanse itself. That’s simply not the case,” he says. “If we managed water as a finite and essential resource, we would be more conservative, cautious, deliberate ... and effective.”

After all, he says, source water stewardship is everyone’s responsibility.

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