We have received a number of questions recently about the water levels at Forge Dam and what the Council is doing to complete the works.
The water level at Forge Dam is currently artificially lowered, to allow safe access for the contractors who are undertaking the embankment wall repair on the north side of the Dam. This does reveal the silt in places. Approximately 5000m3 was removed but the remaining silt has been left to form a mosaic of levels in order to maximise the habitat niches for a range of aquatic life – including areas that should re-vegetate quickly.
The old penstock on the spillway has been letting water through since March, when the de-silting work revealed the opening …….the penstock gate having rotted away long ago. At the moment there is little flow over the spillway brim. During average river flows there is sufficient water coming into the Dam to fill the millpond and to overtop the spillway. This was checked in May when the millpond re-filled following the completion of the de-silting phase of works.
We understand that the Council is considering the best options for installing a controllable penstock for the spillway sluice. One option was to find a permanent way to seal the opening, however it has become increasingly clear that water being able to travel through the sluice serves a valuable function in protecting the downstream environment at Wire Mill Dam during periods of drought when historically water has always stopped flowing over the spillway. Last year and the year before, the fish at Wire Mill were in considerable distress and additional pumps, the Fire and Rescue Service and regular monitoring by the Environment Agency were required to maintain sufficient oxygen levels in that millpond. A controllable device on the Forge Dam spillway is a better solution and professional advice is being sought.
Once the embankment repairs are complete (see the last blog and photos) there is a final phase of works to be completed in the autumn which will include:
Upgrading paths and re-surfacing around the pond and re-installing the memorial benches which were temporarily removed during the works
Re-surfacing the areas used as compounds and haulage routes during the main works
Tidying up general appearance of areas used as compounds
Re-seeding areas with woodland wildflower mix and planting a hedgerow along the bridleway.