Hatches Harbor (Race Run) Dike.
Somewhat like the West End Breakwater, the Hatches Harbor Dike is a human-made feature of almost geographic proportion, roughly a half mile in length, separating the sea from the Race Run, which could reach as far as the Truro line during spring high tides in the 19th century. The dike was completed in 1931 to cut down the mosquito population of the Cape End by “preventing the flood tides entering the old inlet and leaving pools of salt water to stagnate and breed the pests,” as The Advocate put it on 2 April 1931. Some time before 1946, the dike was breached, flooding the town’s rudimentary airport and unleashing the mosquito hordes to the point, The Advocate reported on 6 June 1946 that “[h]ousewives found it impossible to hang out their clothes and home gardeners were ready to give up all attempts to get their Spring planting done.” Lieutenant Governor Robert F. Bradford, a descendant of the Mayflower passenger William Bradford and — therefore — connected directly to Bradford Street, came to town in August 1946 campaigning for the governorship. He caught an earful about the unrepaired dike, returned to the State House, and saw to it that a contract was let. One hundred tons of rubble were carted out to the tip to strengthen the earthwork. Bradford, a Republican, won 60 percent of the vote in Provincetown (of 1,028 votes cast) that November.
With a greater understanding of the effects on the natural environment of such large works, the National Park Service determined that the dike was actually contributing to the problem of mosquito infestation. On the upland side of the dike, “the lowered water level and lack of tides made it impossible for estuarine fish to reach and feed on the wetland service,” the National Park Service said in its Hatches Harbor Salt Marsh Restoration pamphlet. “One result was that important predators to mosquito larvae, especially killifish, could not reach mosquito breeding site in high marsh pools.” In 1987, the park service removed a tide gate in a small culvert between the wetlands. In 1999, it replaced the single culvert with four seven-by-three-foot box culverts (pictured), which can be opened or closed, allowing tide heights and salinities in the upland marsh to approach those in the shoreline marsh.
¶ Last updated on 16 April 2017.