Barton Broad is a large lake that forms part of the River Ant which gives its name to a 164-hectare (410-acre) nature reserve north-east of Norwich in Norfolk.

[12] Photographs taken in the late-19th and early-20th centuries show that water quality at the time was good, supporting large lily beds with reed swamp fringing the banks of the broad.

The water was clogged with mud and algae, and algal blooms contained toxins which could be fatal to farm animals and domestic pets.

The beautiful Pleasure Island, in the middle of the Broad, became degraded as the reeds which protected it from wash created by boats and from wind-generated waves died back, resulting in the banks being scoured away.

The Broad continued to be used by leisure boats, and was also the home of the Nancy Oldfield Trust, a group which helped people with limited mobility to experience the joys of sailing.

The growth of population led to the construction of municipal sewage treatment works, which discharged treated effluent containing high concentrations of phosphorus into the rivers.

A survey to assess the size of the problem found that for sailing boats with keels, there was only a narrow central strip of water with sufficient depth, and even that contained shallow spots.

[15] Anglian Water operated two main sewage treatment works that affected Barton Broad, at Stalham and North Walsham.

[9] The cost of removing huge volumes of contaminated sludge was significant, but an application was made to the National Lottery's Millennium Commission, as the restoration of wetland habitat seems a good fit to the requirements of that fund.

To overcome this problem, pike and perch were introduced to the Broad, and significantly reduced the numbers of small fish, allowing the daphnia to thrive.

Gauze filters at intervals along the skirts allowed water to pass between controlled and non-controlled areas, but prevented the passage of fish.

The Millennium Commission grant was conditional on public access being improved, and a number of boardwalks were created to allow pedestrians to view and enjoy the broad and nature reserve.