Natural History

Statistics

SIZE: approximately 92 acres of salt pond (1980 survey 91.4 acres).

LOCATION: on the Hull/Cohasset border

DEPTH: approximately 0–6 feet. The depth varies with the tides and seasons and is controlled by a tidal gate at the west end (West Corner) of the pond.

WATER VOLUME: 98,310,00 gallons or 13,140,000 cubic feet (calculated in 1980)

FLUSHING TIME: is defined as the time it takes one pond volume of water to discharge from the pond. In 1980, the flushing time was figured as 71 days because the Pond area is large relative to the watershed area. Note: It is easier to get water out of the Pond than to refill it as water drains out of the gate at low tide, but typically it takes several high tides to replace the water.

Bathymetry of Straits Pond created from 2020 midge sampling program. At each sample point, the water depth was measured. The data points were normalized to a three foot Pond surface elevation above sea level then hand contoured.

WATERSHED TOPOGRAPHY: Modest bedrock uplands cut by linear drainages to the south. Bedrock hills separated by low coastal plains to the north. The highest point is just west of Tad Lane in Cohasset for an elevation of 108′ above mean sea level (MSL); the lowest elevation is at the bottom of Straits Pond at an elevation of -6 ft below MSL. Tide gate is at an elevation of 3.0ft above MSL

2016 NOAA LiDAR based digital elevation model accurate to within 15″. The catchment basin for freshwater flowing into the Pond is outlined in black.

WATERSHED HYDROLOGY: Several drainages or watersheds comprise the overall catchment basin of the Pond. The largest is the Rattlesnake Run watershed which stretches from Cedar St in Cohasset to the Pond.