Cocheco River Watershed
Twombly Brook crosses into Rollinsford from Somersworth, in an area of emergent wetland, east of Clement Road. The brook flows past several homes along this road as it moves south. It crosses a small farm field and then passes under Rollins Road and the Boston and Maine Railroad tracks. Twombly Brook flows into large forested area, where it joins Fresh Creek.
Rollins Brook flows out of a marsh along Rollinsford’s border with Dover, north of Rollins Road. It flows around a large hay field, and passes under Rollins Road just north of the Wentworth Greenhouse facility. The brook crosses the Boston and Maine Railroad tracks and flows south for a half mile, until it joins Fresh Creek.
Fresh Creek begins in a marsh, near a junk car lot on Somersworth Road. The creek crosses Somersworth Road and the New Hampshire Northcoast Railroad tracks, and then passes through a field in an artificially straightened channel. It crosses Rollins Road and flows past several homes, as it runs parallel to the railroad tracks. Fresh Creek then passes through a culvert under the tracks, and flows between several large farm fields, before passing into a mile long stretch of forest. It passes a farm on Portland Avenue, then crosses under the road and turns east. The creek then passes through a culvert under Old Mill Lane and forms a pond behind a causeway on Gulf Road in Dover. This pond is bordered by a large field along Baer Road. Fresh Creek passes into Dover and then joins the Cocheco River.
Salmon Falls River Watershed
Garvin Brook begins near a farm on Sligo Road. It flows south along the border of this farm and forms a small pond at a dam near Rollinsford’s border with Dover. The brook passes this dam into Dover, on its way to join the Salmon Falls River.
The Salmon Falls River forms Rollinsford’s eastern border with Maine. It flows in from Somersworth, in a relatively undeveloped area of forest. It backs up behind the Rollinsford Dam, at the Boston and Maine Railroad bridge in downtown Rollinsford. The river then forms a series of rapids as it passes the mill buildings and the Rollinsford Sewage Treatment Plant. The river forms another reservoir where it meets a dam at Portland Avenue. The shoreline of the Salmon Falls River becomes fairly undeveloped as it passes mostly forest and farms on its way south. It passes one small subdivision on River Road and then crosses into Dover.