Salt Marsh Restoration Program
The Conservation Commission initiated the salt marsh restoration program in 1971 as a result of an open space and tidal wetland restoration study completed the same year by Yale University, entitled “The Pine Creek and Mill River Watersheds, Fairfield, Connecticut, An Ecological Guide to Open Space Land Use” by Beals and Westover. This study demonstrated the damage to tidal wetland ecological values caused by the flood control dikes put in place during the previous two decades, and recommended that the dike at the Pine Creek salt marsh be removed to re-establish sufficient salt-water inflow. This recommendation was the foundation for the beginning of the salt marsh restoration program.
Tidal Wetlands and Salt Marshes
What are tidal wetlands and salt marshes and why should anyone be concerned about their condition? Due in great part to the intense pressure to develop along the coastal areas of Connecticut and other states, much work has been done to answer these questions.
Tidal wetlands are low-lying areas adjacent to estuaries or rivers subject to the daily ebb and flow of the tides. The twice-daily inundation by either fresh water or salt water creates an ecological environment that eliminates the typical upland species and favors species that can tolerate such fluctuations in water level. In addition, tidal wetlands are subject to physical variations such as ice flows in winter and floating debris, as well as high levels of sediment deposition.
The physiological conditions that are created by salt water tides are even more restrictive and allow a very limited number of tolerant species. High salt levels in the water even further reduce the number of species that can survive in these extreme conditions. The result is a visually recognizable ecosystem called a salt marsh. Salt marshes are areas where salt water tides flow over low-lying land, and are identifiable by the presence of several species, including Saltmeadow Hay Spartina patens,Saltmarsh Cordgrass Spartina alterniflora, and Salt Grass Distichlis spicata.
Tidal wetlands, in general, and salt marshes, in particular, have been linked to the quality of adjacent bodies of water and the health of their finfish populations. Marshes function as living filters where pollutants are contained, diluted or stabilized as tidewater and stormwater flow through marsh grass and over adjacent mudflats. The marshes are also ecological systems with high biological productivity; nutrients stored and recycled within them provide the foundation of the estuarine food chain. The dead leaves and stems of marsh plants enter the water, are broken down by bacteria, and become the food of fiddler crabs, worms, snails, finfish, and shellfish. The marshes provide nesting, feeding and refuge areas for shorebirds and wildlife communities; they store floodwater, stabilize the shoreline, and act as buffers against wave energy. Their recreational, scientific, educational, and scenic values are easy to see.
Damage to Tidal Wetlands
Since the first humans clustered together, we have been drawn to water. Whether it is seaside, lakeside or riverside, we have used water for all the resources it provides, as well as its utility for transportation. Over the centuries of human development, this has led to destruction of the adjacent resources, in the last century at a very high rate. The Connecticut Department of Environmental Protection estimates that 30% of the State’s tidal wetlands and their beneficial functions and values were lost between the 1880’s and 1970”s, when marshes were diked and filled for flood protection, garbage disposal, road construction, industrial and residential development, and many other purposes.
Beals and Westover’s report on Pine Creek and the Mill River documented activities that had harmed the natural ecological functions of the original salt marsh system of Pine Creek. One of the most damaging activities, but one with potential for remediation, was the construction of a flood control dike that extended along the low-lying areas adjacent to Pine Creek, and actually filled a section of Pine Creek, forcing the flow of the creek through culverts. These culverts were fitted with flapper tidegates, allowing stormwater to flow out to Long Island Sound but stopping the ebb and flow of tides.
As a result, the entire salt marsh regime was eliminated. Salt water became fresh water. Salt was leached from the soils by rain. Tidal scour was eliminated, resulting in ditches that were filled with sediment and floating debris. More mosquitoes than ever bred in stagnant pools. The salt tolerant plants lost their competitive advantage, and were soon replaced by Common Reed Phragmites australis. Exclusion of the daily tide killed off all saltwater-dependent oyster, clam, mussel, fish and crab populations in the diked creeks and marshes. Destruction of wetland habitat quickly eliminated the wading birds, waterfowl, and wildlife previously found in and around the marshes. The once remarkable attributes of a balanced ecological system disappeared.
By 1974, only about 70 wetland acres remained undiked or unfilled in the Fairfield coastal area – a loss of 94% from an estimated 1,250 acres in 1914. Only 17 (out of 600) acres remained in the Pine Creek estuary. The Town was faced with a difficult and important question - how to restore and protect the beneficial values of the tidal wetlands and still provide necessary flood protection.
Marsh Restoration Process
With the direction given in the Beals and Westover report to restore the salt marshes, the Town’s Conservation Commission held public hearings and subsequently adopted a marsh restoration plan in 1974. State and Federal permits for work in wetlands were obtained and Town funding was allocated. To help maintain flood protection, the Town built a new dike around part of the marsh before removing the cross-channel dike. The next big step was to remove a section of one dike across Pine Creek to restore part of the natural tidal prism and provide the millions of cubic feet of daily tidal flow needed to support a healthy marsh system. These actions were accomplished in 1980.
At the same time, self-regulating tidegates (SRT’s) were designed to replace the flapper tidegates in an upstream section of dike across the Creek. Float systems on the SRTs are adjusted so the gates allow enough tidal flow for marsh restoration but automatically close at a predetermined tide elevation before the flood-causing part of the tide range passes through. The Pine Creek SRTs were installed in 1981; their design and operation have been fine-tuned over the years and their reliability and beneficial effects well documented.
The Salt Marsh Restoration Program Today
Over the last twenty years, the Conservation Commission has continued with its salt marsh restoration goals, and expanded its area of concern into the five other estuaries of the Town: Ash Creek, Turney Creek, Mill River, Horse Tavern Creek, and Sasco Creek. The Conservation Commission currently operates eight SRTs, and has restored approximately 120 acres, with 100 more acres that could be restored. The success of the program has been documented by Fairfield University in on-going studies. Presentations have been made by the Conservation Director, Thomas Steinke, and others, demonstrating the enhancement of the natural resources in the area.
In October 1997 the Commission adopted its “Multiple Use Management Plan For Coastal Open Space”. This document establishes as one of its primary coastal-wide goals to continue restoration of degraded tidal wetlands, including filled wetlands previously isolated from tidal flow by flood control dikes, where such restoration will provide public health, safety, and welfare benefits, and enhance the overall quality of natural resources and ecological functions in the coastal area.
For additional information on the program, please contact the Conservation Department. Better yet, take a walk along the flood control dike off Old Dam Road to view the beauty and wildlife found in the salt marshes of Pine Creek.