The 161 feet (49 m) high dam is of concrete buttress construction and impounds the River Haddeo to provide a water storage capacity of some 21,000 megalitres over an area of 374 acres (1.51 km2).

The tributary valleys include the River Pulham, which passes the village of Brompton Regis and continues to Hartford where it joins the Haddeo.

It showed that the main thermal effects of impoundment and regulation have been to raise mean water temperature, eliminate freezing conditions, depress summer maximum values, delay the annual cycle and reduce diurnal fluctuation.

[2] In 2001 - 2002 South West Water commissioned a detailed assessment of fish population, physical habitat, flow and water quality data within the River Haddeo, since it has been subject to regulated releases from Wimbleball Reservoir, to identify potential bottlenecks restricting the development of juvenile salmon populations.

In December 2005 the trust was successful in obtaining funding for a £1 million project to provide a new rowing store, conversion of barn space into showers and changing areas, new sports equipment, an accessible bird hide, and interpretation, improved access, and signage around the site.