Hydro-Brake® Flood flow controls on Blackburn Brook prevent flooding on the Thorncliffe Industrial Estate just outside Sheffield, in the North of England.

Situation

The Blackburn Brook runs through a 500 m (546 yd) long culvert beneath the Thorncliffe Industrial Estate.  The small existing weir, situated on the brook, creates a holding capacity of just 4,000 m³; this isn’t large enough to provide protection from flooding.  As a result, the industrial estate and nearby housing have suffered flood damage and disruption. 

Problem

The Thorncliffe Industrial Estate and nearby housing suffered from extensive flooding in 2007 due to a 150 year storm event which exceeded the capacity of a culvert on the local Blackburn Brook.  The flood caused a great deal of damage and a dam was needed to prevent a repeat.

Solution

Two 1 m (3.2 ft) diameter Hydro-Brake® Flood units were installed into a new dam near Devil’s Bridge, on the Blackburn Brook approximately 300 m (328 yds) upstream of the culvert. The dam creates a potential storage capacity of 32,000 m³ (8.4 million gallons). 

Outcome

The Hydro-Brake® Flood installation will control the flow, up to a design maximum of 5.7 m³/sec, so will protect the culvert and prevent overtopping.

Above this flow, the stored water will back up behind the dam but the flow characteristic of the devices limits the speed of back-up compared to other forms of flow control, saving in the region of 10-15 per cent of land grab.

“By installing two 1,098 mm diameter Hydro-Brake® Flow Control devices we can control the water flow to match the maximum capacity of the culvert," said João Santa-Clara, consulting engineer, JBA Consulting. "We were able to achieve this without the stored water taking excessive land in a restricted area and country park.