Durrants Lakes/R. Bulbourne

Background Information

Durrants lakes comprise two spring-fed lakes built in the 1970s when the former Water Cress beds were deepened to extract gravel. The lakes run adjacent to the River Bulbourne, a tributary of the River Gade, one of several chalk streams found in the Chilton downlands. Durrants lakes are owned by Dacorum Borough Council and leased to the local Boxmoor and District angling Club who run the site as a course fishing complex. The smaller of the two lakes is also used by the First Apsley Scouts, for canoe and watersports activities.

Scope of the Project

Several breaches had formed between the adjacent River Bulbourne and Durants lakes, causing excess water to enter the fishery. This resulted in frequent flooding of the site and in effect brought the lakes online with the river system, when before they were an entirely separate entity. Along with this several hundred meters of the marginal backside, habitat had been lost and was in dire need of restoration.

Our Solution

The larger downstream breach that had eroded over 100m of a causeway between the adjacent river and the small lake took a slightly different approach. For this section, we installed a 1metre high Nicospan revetment on both the lakeside and the riverside of the causeway. The revetment was infilled by dredging the adjacent fishing lake, which had become heavily silted since being connected to the river.