Weir demolition complete

Wednesday of this week marked the start of the removal of the weir that spans the river between Harding’s Moor and Bulbourne Meadow. The work was delivered by B W Services with great efficiency. The identified section of concrete took just about three days to remove. And, as work was progressing, fish were seen regularly swimming upstream through the new breach and a Little Egret was attentively trying to fish downstream by the bales that had been temporarily inserted as silt traps for any debris loosened by the works.

On Wednesday 16^th March

Temporary silt traps created using posts and bales

On Thursday 17^th - Friday 18^th March

Demolition and removal of concrete rubble

An immediate speeding up of the flow upstream was apparent and we look forward to seeing sediment incrementally washed away and gravels exposed.

On Friday 18^th March

The riverbed upstream looked a lot clearer, with sediment already beginning to clear

Key benefits of removing dams and weirs are:

• Re-establishing the natural continuity of hydromorphological processes (reducing impoundment, upstream siltation and downstream erosion) along the river system.
• Re-establishing natural habitat diversity.
• Reducing barriers to natural migration and movement of fish and other aquatic species.
• Re-establishing a self-sustaining river system, without the need for further maintenance.
• Re-establishing natural continuity in temperature, oxygen balance, pH and salinity.

Finally, special thanks to Trust volunteer David Warriner for this excellent video, filmed as the last of the concrete cill was broken up.




The work was funded by grant aid by the Colne Catchment Action Network