By MICHAEL KITCH, LACONIA DAILY SUN
MEREDITH — Three years in the making, a draft of the Watershed Restoration Plan for Lake Waukewan and Lake Winona was presented to more than two dozen residents at the Community Center this week.
Prepared by the Lake Winnipesaukee Association and FB Environmental Associates of Portsmouth, the plan is the successor to the Waukewan Management Plan completed in 2005 and part of what Pat Tarpey, executive director of the association, called a "lakewide" approach to preserving and enhancing water quality in Lake Winnipesaukee. The report runs to 95 pages, excluding the appendices.
"You can't hear too much about phosphorus," said Forrest Bell of FB Environmental Associates, signaling that stanching the flow of phosphorus into the lakes is the overriding theme of the plan. The report quantifies the primary sources of phosphorus loading and projects future sources of phosphorus, together with the rate at which it may reach the lakes. The sources of phosphorus are ranked in order of priority and steps to reduce phosphorus loading are recommended.
The Waukewan watershed stretched across five towns — Meredith, Center Harbor, New Hampton, Ashland and Holderness — and 7,162 acres, of which 951 acres, or 13 percent of the area are developed and 6,000 acres are forested.
Storm water run-off is the primary source of pollution in the watershed. While run-off is slowed, filtered and dissipated in forested land, where land has been developed storm water carries between five and 10 times the amount of phosphorus flowing from forested areas. Consequently development, along with recreation, septic systems and erosion pose the primary threats to water quality. Phosphorus is a common constituent of agricultural fertilizers, manure and organic wastes in sewage and industrial effluent, according to the U.S. Geological Survey.
A survey of the watershed identified 65 sites that significantly impact water quality by carrying sediment laden with phosphorus, the top six of which alone represent a significant share of the pollution. The plan includes recommendations for remediating these sites as well as measures for maintaining septic systems, which represent the second and third most significant source of pollution on Lake Waukewan and Lake Winona respectively.
Apart from addressing immediate issues, the plan also recommends a series of strategies to safeguard water quality in the long-term. These include applying "best management practices" to restore eroded shorelines, plant vegetative buffers and manage runoff from impervious surface as well as tailoring municipal ordinances ordinances to reduce risks to water quality.
John Edgar, director of community development said that among the virtues of the plan is that it has not only identified sources of pollution, but also recommended cost-effective means of addressing them, which for relatively modest investment will yield significant results. He said that recommendations offer the prospect of not only forestalling further deterioration of the water quality in the two lakes, but of enhancing it.