WATER RESOURCE PROTECTION

The entirety of Hanover lies within the Narragansett Basin geology formation, a 1,000-square-mile basin formed by tectonic activity around 315 million years ago. The bedrock here includes coal, conglomerate, siltstone, sandstone and shale, which are overlain by a large number of swampy low-lying forests.¹

Hanover’s ecological assets are its abundant wetlands, streams, and water bodies. The Town is within the North and South Rivers Watershed. Water from Hanover first drains into the Indian Head River or the Third Herring Brook that run along the south and east town borders. Both of these waterways and the estuarine fresh/brackish tidal swamps that form along their edges provide habitat to rare species.² As these two rivers converge into the North River, they create a freshwater intertidal marsh that drains into the Atlantic. Freshwater tidal marshes are globally rare ecosystems; Hanover’s “Crotch” provides habitat for many rare species and is designated by the Natural Heritage and Endangered Species Program (NHESP) as a high-priority natural community.² Because Hanover has experienced extensive development, there aren’t other intact blocks of regionally significant habitat, but that means protecting natural landscapes and increasing biodiversity in small open spaces, like B. Everett Hall Field, is all the more important.

Wetlands and vernal pools

There are 24 vernal pools certified by the Department of Environmental Protection (DEP) in Hanover; one at B. Everett Hall Field.³ These seasonal ponds remain dry during late summer but fill as rain falls and groundwater rises in the fall and winter, staying wet through spring or early summer. These pools provide important habitat for amphibians and invertebrates to breed without the pressure of predation by fish.

The Hanover area is a patchwork of swampy, low-lying forested wetlands. The Wetlands Protection Act (Massachusetts General Laws (MGL) Chapter 131, Section 40) protects wetlands and the public interests they serve, including flood control, prevention of pollution and storm damage, and protection of public and private water supplies, groundwater supply, fisheries, land containing shellfish, and wildlife habitat. It regulates any work within 100 feet of a wetland resource area.⁴

The Hanover Wetlands Protection Bylaw (General Bylaw Section 6-14) protects all areas defined as wetlands, resource areas, protected districts, and any areas deeded to the care and maintenance of the Conservation Commission and its subcommittee, the Open Space Committee.⁵

The bylaw extends the protection of these areas beyond that of the Massachusetts Wetlands Protection Act. In Hanover, protections extend to any freshwater wetlands, marshes, wet meadows, bogs, swamps, vernal ponds, springs, banks, reservoirs, lakes, ponds of any size, beaches, estuaries, lands under water bodies, and intermittent streams/brooks/creeks and buffers of 100 feet around each.⁵

Vernal pools, including the pond east of Silver Street at B. Everett Hall Field, are subject to the local laws’ protections. In addition to the scientific definitions found in regulations under the Wetlands Protection Act, the town bylaw defines vernal pools as “any confined basin or depression not occuring in existing lawns, gardens, landscaped areas, or driveways which, at least in most years, holds water for a minimum of two continuous months during the spring and/or summer, contains at least 200 cubic feet of water at some time during most years, is free from adult predatory fish populations, and provides essential breeding and rearing habitat functions for amphibian, reptile, or other vernal pool community species, regardless of whether the site has been certified by the Massachusetts Division of Fisheries and Wildlife.”⁵

All recommendations for the B. Everett Hall Field landscape plan will consider the vernal pool a sensitive area and aim to protect the critical natural habitat and abide by local and state regulations.