By Alicia Carlson and Holly Green
When you look at your local surface water supply, what do you see? If you see a shoreline surrounded by shrubs and trees, you likely have few problems with erosion and turbidity. Forested lands are an important first step in protecting surface waters. They can help to ensure a cleaner water supply than in a more developed watershed.
If your town or city is expanding and development is encroaching on forest lands, then now may be the time for you to consider conserving those important lands. Even if your municipality is not currently expanding, think about how the lands will be used in the future. Are they mostly privately owned now?
How much money are you willing to spend now by investing in land conservation to ensure a clean, reliable source of water in the future? There is not one right answer. The needs of each municipality are unique. Perhaps learning more about the benefits of land conservation will help you find the answer that will suit your residents' needs.
Several large cities realized early on the importance to protect their source water areas. In particular, Boston, New York, San Francisco and Seattle all located waters and lands outside of their metro areas for drinking water. These large cities have greater resources at hand for protecting their water supplies than do small cities, towns or small public water systems serving, for instance, a condominium association.
A number of New Hampshire cities and towns have also taken the approach of land conservation and ownership. Most notably, Manchester Water Works has owned and operated its drinking water supply since 1874. The city of Manchester currently owns 8,000 acres of the Lake Massabesic watershed, including 95 percent of the shoreline. Many other surface water sources in New Hampshire are located in watersheds that are largely protected-Concord's Penacook Lake, Keene's Babbidge Pond and Hanover's reservoirs are just a few.
Impacts from Forested Land vs. Developed Land
Forested lands provide many benefits. One primary benefit for water supplies is that when water washes over a forested landscape, it tends to move slower than over a developed landscape. Slower water flow means reduced chance of erosion and runoff of nutrients to surface waters.
Slower water flow also means increased infiltration. When water is allowed to infiltrate to the soil and groundwater, nutrients and other chemicals are more likely to be used by plants or degraded by soil decomposers.
In developed areas, there is little infiltration and the water moves quickly over the landscape; runoff and erosion are prevalent. There is a well-established relationship between impervious cover (hard surfaces such as pavement and rooftops) and reduced water quality. And, with the national rate of land development now twice that of population growth, there is reason for concern.
A 2005 report by the U.S. Geological Survey, with support from the New Hampshire Department of Environmental Services (DES), showed that when impervious surfaces increased in a corridor around a stream, turbidity also increased. Urban land use within a one-kilometer radius or a 25-meter stream buffer upstream of a sampling site showed the greatest correlation to high turbidity levels. Sample sites that were surrounded by forested areas had lower turbidity levels.
Water Quality Costs for Water Suppliers
Treatment of drinking water is not a static issue. As new contaminants are discovered, new and more elaborate treatment techniques are required. While advances in technology allow us to treat for more contaminants than ever before, these treatments are not necessarily a cheap fix. Costs are highly variable depending on the treatment techniques being used by a water system.
A 2008 study by the U.S. Environmental Protection Agency, U.S. Forest Service, and Trust for Public Land linked declining forest cover in water supply watersheds with lower water quality and increased water treatment costs. Among the various measures of land cover, such as forest cover or urban cover in the entire watershed, forest cover within a 100-foot buffer around water bodies showed the strongest correlation with a water quality index comprising total organic carbon, turbidity and alkalinity. The study was based on a survey of 60 water treatment plants across the country treating between 1 million and 100 million gallons per day.
Other studies have shown that processes such as flocculation (the process whereby colloids come out of suspension in the form of floc or flakes) and filtration can be omitted in water supplies with high forest land cover. One study estimated that a one percent increase in sediment or turbidity levels would lead to up to a 0.30 percent increase in treatment costs. Although this sounds minimal, any increase in costs is not welcome in the current economy.
Due to advances in technology, some water suppliers have stopped focusing on protecting and managing the source waters in favor of relying on high-tech treatment systems. What will this mean for the drinking water of the future?
Projected Demands on Water Supply Forests
In 2005, it was estimated that nearly 28 percent of New Hampshire lands were protected. However, 75 percent of those lands are in the northern half of the state. Development is occurring most rapidly in the four southeastern counties, which comprise only one third of the state's land. According to U.S. Census data, between 2000 and 2010, New Hampshire's population grew 6.5 percent, which is the highest percentage growth of the New England states. The growth rate is projected to be 28 percent between 2000 and 2025. The number of towns classified as rural will drop to 72 by 2025, down from 139 in 1970.
According to a U.S. Forest Service report published in 2010, 78 out of 529 watersheds in the Northeast and Midwest United States supply the drinking water for nearly 38 million people. It is estimated that the predominantly privately owned forests in these watersheds are being converted to other uses at a rate of 350 acres per day. By 2030, these areas may lose 12 million acres of private forest to other uses. Ninety-two percent of the forests in the northeast and midwest are privately owned. The Society for the Protection of New Hampshire Forests has reported that New Hampshire loses 17,500 acres of forest lands every year.
The U.S. Forest Service study found that several watersheds in New Hampshire are at risk of losing these important, privately owned forest lands that offer a clean source of surface drinking water. Among those watersheds most at risk are the Salmon Falls River, Nashua River and Merrimack River. Keep in mind, these all fall within the areas projected for the greatest growth.
It is now the suburban and urbanizing communities that must deal with the issues of development and managing natural resources. These communities often lack the necessary resources to manage growth and its effects.
Benefits and Drawbacks of Conserving Lands
Costs for water treatment have been shown to be significantly lower in forested watersheds than in more developed watersheds. In 2002, a study by the Trust for Public Land and the American Water Works Association found that for every 10 percent increase in forest cover in a source area, there was a decrease of approximately 20 percent in treatment and chemical costs.
With land conservation, there is little need to upgrade treatment systems to combat new pollutants of concern. Some larger cities are prime examples of this. The New York City and Boston drinking water supply watersheds have avoided water filtration due to the high level of forest lands conserved around their respective surface waters.
Not only does conserving land protect water supplies, it can help maintain the rural character of a town, centralize development, reduce the need for or centralize town services, and provide opportunities for recreation.
There can be economic drawbacks to conserving lands. Some tax revenues may be lost when land is permanently conserved, particularly if a tax-exempt organization is purchasing the land. The Trust for Public Land has many great resources to help municipalities dealing with the prospect of land conservation. One of particular use is Managing Growth: The Impact of Conservation and Development on Property Taxes in New Hampshire. The report includes steps municipalities will need to take to calculate the implications of various ownership scenarios. There are also examples of the different scenarios and how they would affect different types of communities.
Any town or city considering land conservation must weigh its options: what are the short- and long-term costs of all the available approaches?
Funding the Conservation of Land to Protect Water Quality
The New Hampshire Legislature created the Water Supply Land Protection (WSLP) Grant Program in 2000, giving municipalities and nonprofit water suppliers the opportunity to obtain grants for the purchase of land or conservation easements. This grant program is administered by DES and funded by appropriations by the New Hampshire Legislature. Currently there are no WSLP grant funds available, but the grant program is expected to receive $3 million in federal funds during 2011 from the New Hampshire Department of Transportation as part of wetlands mitigation related to the I-93 widening project. Eligibility for these funds will be limited to communities impacted by the I-93 project.
For municipalities throughout the state, there is an alphabet soup of land conservation grant programs available, such as the Farm and Ranch Lands Protection Program and the Wetlands Reserve Program, both administered by the U.S. Department of Agriculture's Natural Resources Conservation Service; the Land and Community Heritage Investment Program; and the Aquatic Resource Mitigation Grants administered by DES. Some municipalities also have region-specific grants available, such as Quabbin-to-Cardigan in the southwest and the Coastal and Estuarine Land Conservation Program.
In other states, examples exist of dedicated funding sources for land conservation for the purpose of clean water, including Rhode Island's "Penny per Hundred" Program, North Carolina's Clean Water Management Trust Fund and Minnesota's Clean Water, Land and Legacy Act grant program.
The "Penny per Hundred" Program collects one cent per 100 gallons of water delivered by water suppliers and sets it aside for land acquisition or water quality improvement projects. Each participating water supplier must spend a minimum of 55 percent for land acquisition-the primary protection activity. More information can be found at Road Island Water Resources Board.
Funding for North Carolina's Clean Water Management Trust Fund (CWMTF) was established by the General Assembly so that, at the end of each fiscal year, 6.5 percent of the unreserved credit balance in the state's General Fund (or a minimum of $30 million) goes into the CWMTF. Revenues from the CWMTF are then allocated in the form of grants to local governments, state agencies and conservation nonprofits to help finance projects that specifically address water pollution problems. More information is available at CWMTF.
Minnesota's Clean Water Fund grant program is funded by a three-eighth's percent increase in the state's sale tax. The Minnesota Constitution, Article XI, Sec. 15 now requires that "33 percent of the receipts shall be deposited in the clean water fund and may be spent only to protect, enhance and restore water quality in lakes, rivers and streams and to protect groundwater from degradation, and at least five percent of the clean water fund must be spent only to protect drinking water sources."
Protecting Tomorrow's Resources
Forests work as a buffer around surface waters. They take up nutrients, reduce the flow of water and help to prevent erosion. Cleaner raw water requires less treatment, and therefore treatment costs in more forested watersheds of drinking water supplies tend to be lower than in more developed watersheds.
Protecting the lands around water supplies or potential water supplies is important to ensure a safe, clean water supply into the future. It is imperative that water systems around New Hampshire assess the threats to their surface waters. Are forest lands prevalent in the watershed? If so, what can be done to ensure their protection into the future?
Every acre conserved helps to keep down the costs of water treatment. How much are you willing to spend in the future on water treatment costs as a consequence of failing to protect water supply lands today?
Alicia Carlson is the source water protection education coordinator with the New Hampshire Department of Environmental Services. Holly Green is coordinator of the Water Supply Land Protection Grant Program, New Hampshire Department of Environmental Services. For more information on this topic, contact Alicia by email or by phone at 603.271.4071. Contact Holly by email or by phone at 603.271.3114.
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Managing Growth: The Impact of Conservation and Development on Property Taxes in New Hampshire.
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Effects of Urbanization on Stream Quality at Selected Sites in the Seacoast Region in New Hampshire, 2001-03.
U.S. Geological Survey.
Ernst, Caryn. 2004.
Protecting the Source: Land Conservation and the Future of America's Drinking Water.
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Land Conservation: A Permanent Solution for Drinking Water Source Protection
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Saving Special Places: Community Funding for Land Conservation
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Source Protection Handbook: Using Land Conservation to Protect Drinking Water Supplies
The Trust for Public Land, 2005
New Hampshire's Changing Landscape-Population Growth and Land Use Changes: What They Mean for the Granite State
Society for the Protection of New Hampshire Forests, 2005