Project Details:

Project Objective:

The main project was to provide a safe migration for fish through a private property in the Trough of Bowland. A river ran around a property, which resulted in ford access to the property. Downstream of the ford, large concrete steps were in place which restricted the fish migration. As a result, the works were split into 2, with the conservation trust being involved in the fish migration and private domestic client involved in the rock wall construction to protect the banking’s from erosion.

Design Solution – Fish Passage:

A design was carried out by the client to create a staggered weir formation upon the existing concrete steps, which created pools of water upon each step to allow fish to migrate. Staggered notches were cut into new timber weir baffles, which reduced the velocity of the water.

Below the new weir configuration, a rock ramp was installed to further reduce the velocity of the water and also reduce turbidity where the river exists the weirs and re-joins the main watercourse.

Design Solution – Bank Protection:

The eroded banking of the river was excavated to firm material, prior to the construction of a rock armour wall, which will absorb and disperse the impact of the river on the banking when in flood conditions.

The rock armour consisted of large rocks in excess of 2 tonnes each, placed in position and angled backwards at 10 degrees. Clean stone was then used to backfill the rock armour wall, prior to topsoil and seed being laid above.