25 for 25: New Hampshire's Dams – The Secret to Our Lakes
By Thomas S. Burack, DES Commissioner
Since 1987, when the National Weather Service has predicted severe rain events to affect New Hampshire, a small, well-prepared crew at the state’s Department of Environmental Services has stood ready to prevent flooding from whatever storm Mother Nature sends our way. The DES Dam Bureau, which joined DES when the agency was created by the legislature in 1987, is responsible for the safety of the more than 2,600 dams in the state, including the year-round maintenance and repair of all 274 state-owned dams. The Dam Bureau ensures that the dams are structurally sound and functioning as designed, so that when severe storms, such as Hurricane Sandy, bring high volumes of water – and they do – the staff can confidently release the right amounts of water from the state-owned dams to reduce flooding. It’s a science and an art that the Dam Bureau has devoted itself to, especially in the last 8 years or so as New Hampshire has experienced three one-hundred year floods and two hurricanes.
State-owned dams impound the largest and most important recreational lakes in the state, including Winnipesaukee, Squam, Winnisquam, Newfound, Sunapee and Ossipee. These lakes provide a myriad of recreational opportunities for boaters, swimmers, anglers, and others, and are home to a rich array of waterfowl, wildlife, fish and other aquatic species. The dams on these large lakes also help to control the volume of water flowing into some of the major rivers of the state, which in turn affect industries and recreation downstream. And this means that water levels must be constantly monitored, even during good weather, and frequent adjustments made by the dam operators to ensure that appropriate levels are maintained.
Many of the state’s dams, particularly those on the large lakes, were constructed in the mid-1800s to provide waterpower to fuel the great Industrial Revolution-era mills of New Hampshire and Massachusetts. Most of the dams that the state owns are well over 100 years old. Because of their age, they require continued attention to maintain them in a safe condition. Twenty-nine of the state-owned dams are “high hazard,” meaning that their failure would cause loss of life downstream, and 53 are “significant hazard” dams, which would cause significant property damage downstream if they failed. More than 4,000 homes, 130 state road crossings and 800 town road crossings would be destroyed or damaged were all of these state-owned dams to fail.
According to the New Hampshire Lake Association’s Report on the Economic Value of New Hampshire’s Surface Waters, New Hampshire’s lakes provide up to $1.5 billion annually of economic benefit to the state, and waterfront property owners pay nearly a quarter-billion dollars annually in property taxes. Since the majority of New Hampshire’s surface waters are impounded by state-owned dams, the upkeep of these dams is vitally important, not only to protect public safety and the environment, but also to maintain the large economic benefits that they provide.
In 1996, a privately-owned, significant hazard dam in Alton failed. One person died, and approximately $8 million worth of property damage occurred when the Rte. 140 road crossing downstream was destroyed. The flooding seven years ago in Alstead also dramatically illustrated the destructive force of a sudden release of stored water, which killed 5 people and caused some $35 million of damage downstream. Using the costs of these tragedies as a yardstick, it is clear that many thousands of lives and hundreds of millions of dollars of property are at risk downstream of state-owned and maintained dams.
To keep all of these dams safe, the Dam Bureau must conduct daily maintenance, including keeping the areas around the dams continually mowed to prevent the growth of woody vegetation whose roots could threaten the safety of the dams. Every day, the Dam Bureau staff performs a unique balancing act of managing water releases from the state-owned dams so as not to cause property damage on the lakes and downstream, while also ensuring appropriate lake levels to support wildlife, boating and all of the many ways in which we love to enjoy our lakes.
As DES recognizes our 25th Anniversary this year, we salute the DES Dam Bureau for the critical role they play in reducing flooding risks during major storm events, and daily in safely maintaining our dams to support economic activity and our wonderful quality of life – proof positive that in New Hampshire a healthy environment and a strong economy are positively linked.
Author’s Note: In recognition of the New Hampshire Department of Environmental Services’ 25th Anniversary, over the course of the year, I am highlighting 25 agency activities, programs, projects and accomplishments of the past 25 years. This article, the 20th in the series, discusses the work of the DES Dam Bureau. All of the editorials in the series are available at http://des.nh.gov/organization/commissioner/25th-anniversary.htm.
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