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Fall River Open Space Plan
ii.) Flood Hazard Areas
Portions of Fall River's primary flood hazard areas were last mapped by the Federal Emergency Management Agency in 1984 while the majority of the City was last mapped in 1981.
The National Flood Insurance Rate maps show V Zones elevations ranging from 17 - 22 feet along the City's coastline on Mount Hope Bay. These 'Velocity Zones' depict areas expected to be affected by high velocity wave action associated with the 100-year coastal flood. Generally, Fall River V-Zones extend roughly to the Conrail tracks in most areas from the Tiverton, R.I. border to the Brightman Street Bridge. The V-Zone extends furthest inland to approximately Davol Street beneath the Route 195 Bridge. Nearly all of this Mapped V-Zone area is bounded by bands of adjacent A-Zones of varying base flood elevations.
From the Brightman Street Bridge north, A Zone varies in width along the Taunton River running parallel to Route 79 to its intersection with North Main Street and then east of Conrail Line by approximately 100 feet. These A Zones depict areas likely to be affected by 100 year flood.
The Quequechan River Basin contains A-Zones along the Route 195 Corridor between the Conrail Line and Britland Park to the north. These Quequechan associated flood areas also include portions of the highway cloverleafs.
Areas of mapped A-Zones are associated with all of Fall River's ponds with the exception of Cook Pond. Surrounding Bleachery Pond A-Zones extend up to 500 feet from the pond including portions of Jefferson Street and surrounded by Endicott and Dickinson Streets. North and South Watuppa Ponds as well as Sawdy Pond have narrow (less than 50 feet to 200 feet) A Zones.
In the largely undeveloped east end watershed lands of Fall River, A Zones exist in a narrow band along Miller Brook to its head near the intersection of Copicut Hill Road and Yellow Hill Road. The Copicut Reservoir and the Copicut Swamp north of Quanipaug Road are also mapped as having areas likely to be flooded as a result of the 100-year flood. Isolated A-Zone exists east of Blossom Road along the tributaries to King Philip Brook. Isolated areas of A and B Zones also exist scattered throughout Freetown-Fall River State Forest along small brooks.
Wetlands in the urban western half of Fall River have been highly impacted by industrial, commercial and residential land uses and growth particularly in the late 19th century. A number of wetland types in coastal areas such as saltmarsh and submerged aquatic vegetation (i.e. eelgrass) have nearly disappeared. A 1985 survey revealed less than 4 acres of saltmarsh remaining on the shores of Mount Hope Bay.
The inland wetlands in western Fall River tend to lie immediately adjacent to small brooks or ponds such as Steep Brook, Cook Pond and Bleachery Pond. As a result of past wetlands filling and development in close proximity to wetlands borders, many of the remaining inland wetlands have been degraded in close proximity to wetlands borders, many of the remaining inland wetlands have been degraded by sedimentation and other pollution entering the wetland and by alteration of the flow rates, temperature and volume of water moving through the wetland areas. These kinds of alteration encourage the proliferation of invasive, or nuisance species such as phragmites and purple loosestrife, and these species tend to crowd out the native plants and greatly reduce the diversity of species and wildlife habitat.
Some areas remain which support native wetlands vegetation and perform one or more important wetlands functions, such as water pollution abatement, flood control or provision of wildlife habitat. Preservation of "green islands" such as these with adequate buffer zones can contribute significantly to the improvement of urban environments which have been densely developed. The remaining wetlands in western Fall River tend to lie immediately adjacent to small brooks or ponds such as Steep Brook, Sucker Brook, Cook Pond and the Bleachery Ponds. The majority of these small wetland systems are encroached upon and degraded.
East of the Watuppa Ponds, however, the City has preserved some very large, important wetland systems as part of the Watuppa and Copicut watershed lands. Wetlands within the Freetown-Fall River State Forest and large tracts owned by the Acushnet Sawmills Company also remain in near pristine quality. The dominant wetland type in these areas is red maple swamp. Four stream subwatersheds compose the bulk of these forested wetlands: King Philip/Blossom Brook which flows into the North Watuppa Pond, Miller Brook flowing into the Copicut Reservoir, Bread and Cheese Brook which flows south to the Westport River and the Copicut River. Finally, Pond Swamp lies at the extreme north end of the North Watuppa Pond above Wilson Road.
This large forested wetland lies north of the Copicut Reservoir. The majority of the area is owned by the City of Fall River with portions owned by the Commonwealth of Massachusetts and Acushnet Sawmills. The Copicut Swamp is significant in that it includes pure stands of Atlantic White Cedar and provides the majority of freshwater flow into the Copicut Reservoir, the City's secondary water supply. The entire Copicut system comprised of this swamp and the Miller Brook area contain the City's largest areas of priority habitats for rare and endangered species according to the Massachusetts Natural Heritage and Endangered Species Program. For a complete list of rare species observed in this area see the Fisheries and Wildlife section. only 3 pages away!
Groundwater conditions within Fall River vary greatly from one watershed to the next. Existing data reveals that the aquifer within the coastal drainage basins have only moderate potential for producing water supplies. The City of Fall River currently receives 100% of its water from surface water bodies, since these are the most available and plentiful potable sources.
The principal groundwater aquifers are hydrologically connected to their local surface water bodies. This means that when something happens to one, it will eventually affect the other. For example, if pollution enters the aquifer from any point, it will likely find its way into the open body of water. Similarly, if the pond or reservoir level drops (due to overuse or drought) the water table is correspondingly depleted. The areas that are expected to contain the best groundwater supplies are also the places that are most likely to transmit pollutants.
Aquifers normally exist within stratified, unconsolidated drift deposits of sand, gravel and silt. They generally are located in valleys and lowland areas and are commonly underlaid by till and bedrock.
NORTH WATUPPA WATERSHED
The groundwater potential within this watershed is low with the only area of promise lying around the northern end of North Watuppa Pond, where the rate of 100 gallons per minute is anticipated. Most of the large kame deposit and sandy till are shown as having no real groundwater potential at all.
RATTLESNAKE BROOK WATERSHED
The only area with any groundwater producing potential is the small outwash deposit on the northern city boundary. This 47.1 acre area is expected to provide less than 100 gallons per minute, with only a 5.8 acre recharge area outside of the aquifer. However, since the majority of the actual outwash deposit lies north of the city line, more groundwater may be tapped than originally anticipated. Once again, the sandy gravel deposit is not considered a potential source of groundwater.
BREAD AND CHEESE BROOK WATERSHED
The kame delta deposits which straddle the boundary between this and the North Watuppa Watershed show the best groundwater potential in this area. An area smaller than the actual deposit is shown as being capable of producing less than 100 gallons per minute.
Overall, this watershed appears to be the most promising for aquifer yield. The kame and outwash soils north of the Copicut Reservoir seem to contain fairly large quantities of groundwater. A small elliptical area of 144.3 acres extends to produce between 100 and 300 gallons per minute. A second area of 592.5 acres to contain supplies of less than 100 gallons per minute. A 416.1 acre recharge area outside of the aquifer has also been calculated. Most of this aquifer area occupies the Copicut Swamp. Since this wetlands area is probably not well suited for building structures, it is also less likely to receive direct infiltration of pollutants.
SHINGLE ISLAND WATERSHED
This area is shown as having no groundwater aquifer potential. Since it is completely underlaid with glacial till except for some minor wetland areas, there is no reason to suspect that any major source exists in this part of the Shingle Island Watershed.
In conclusion, the Copicut Reservoir Watershed seems to contain the most potential for aquifer development. The Rattlesnake Brook, North Watuppa and Bread and Cheese watersheds all seem to have some small potential. Greater aquifer potential may be located in any of these areas. The Shingle Island Watershed shows the least aquifer potential.