25 for 25: Restoring the "Bread Basket" of the Coast
By Thomas S. Burack, DES Commissioner
Tidal salt marshes are an important but underappreciated aspect of New Hampshire's 18 miles of seacoast and 130 miles of estuarine shoreline. Salt marshes from Portsmouth to Seabrook have been damaged or destroyed by roads, by undersized culverts that don't provide for adequate tidal exchange, by filling with rocks and dirt to create buildable land, and by being used as disposal locations for spoils (materials) from harbor dredging. Today there are about 6,000 acres of salt marsh in New Hampshire – 20% less than when the coastal region was first settled. For the New Hampshire Department of Environmental Services—marking its 25th anniversary this year—this loss has inspired a successful collaborative effort to restore the critical role salt marshes play in our ecosystem.
Our salt marshes provide wildlife habitat, buffer water quality, and protect the coast line from coastal storms like nor'easters. Salt marshes are the "bread basket" of the coast supporting the fishing industry by providing food and shelter for finfish and shellfish, and slowing flood waters to avoid destruction of coastal properties.
Since the early 1990's the DES Coastal Program and Wetlands Bureau staff have worked in partnership with local towns, other state and federal agencies, and non-profit organizations, as well as with diverse funding contributors to undo the damage to our salt marshes. These collaborations and partnerships across 30 different projects have resulted in the restoration of about 600 acres of salt marsh. Salt marsh restoration projects, which aim to bring back natural conditions, involve activities such as removal of fill, creation of pools and tidal creeks, and removal of undersized culverts. The tides are the lifelines for salt marshes; without them they choke to death.
As an example, at the Awcomin salt marsh, located just to the west of Rye Harbor, dredged materials from the harbor were disposed of within a 25 plus acre containment dike constructed directly on the salt marsh in 1941 and again in 1962. Sea water could no longer enter the containment area and fresh water from rain and snow was trapped. Tidal exchange and fresh water runoff, together known as tidal flushing, are essential to a viable salt marsh ecosystem. The restoration process involved removing over 100,000 cubic yards of dredge spoils from the site in order to restore or replicate the original drainage pattern. Today the site has regained much of its vitality and is a great spot for watching shore birds. The Town of Rye has been a leader in salt marsh restoration in New Hampshire.
The Little River salt marsh restoration in North Hampton faced severe tidal restriction due to an undersized roadway culvert and a channel through the barrier beach which was blocked with sand. Restoration project partners, including the Town of North Hampton and local private citizens raised a total of $1.31 million to bring the project to fruition. In 2000, a pair of 6 ft. high x 12 ft. wide concrete box culverts were installed in place of the existing 48 inch pipe that had been the only connection between the salt marsh and the sea since 1948. The success of the project received national recognition in 2002 when President George W. Bush awarded the Little River Salt March Restoration Team the Coastal America Award.
Healthy salt marshes are not only rich with life, they are also part of nature's basic strategy of protecting our coastlines from a changing climate, including a greater frequency of strong storms and sea levels rise. Restored salt marshes, free of tidal restrictions, are more resilient and better equipped to help mitigate the potential damage from severe coastal storms, such as recently seen on the East Coast with Hurricane Sandy. We have certainly worked over the last 25 years to correct human impacts on salt marshes, and we will be looking to our salt marshes over the next 25 years to help us to adapt to future changes and the needs of our coastal areas.
Author's Note: In recognition of the NH Department of Environmental Services' 25th Anniversary, I am highlighting 25 agency activities, programs, and accomplishments of the past 25 years. This article, 23rd in the series, discusses the long-term successes, planning, and future commitment to restore salt marshes to the critical role they play in our local and regional ecosystem of environment and economy. This series of anniversary editorials are available at http://des.nh.gov/organization/commissioner/25th-anniversary.htm.
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