REPAIRS TO THE DAM AT PAUL’S POND
June 23rd, 2016
I have been advised of the information below by the Council’s Parks Officer:
“On the 4th July we intend to start essential dam works at Paul’s Pond. Since December 2015 we have been monitoring the dam as a small depression was seen by the dam wall close to where the valve chamber is located. In March the situation changed dramatically with a large swallow hole appearing on the other side of the dam path close to the valve chamber. As a result of this we brought in a Reservoir Inspector to look at the situation. The outcome of the survey was a leaking dam wall and emergency repairs required to prevent a breach leading to a loss of the contained water.
Please note that the current position is not life threatening or likely to cause substantial damage to assets.
The works are going to entail: –
An additional valve attached behind the existing valve to have a back-up in case one of the valves fail.
A 600mm lowering of the water level to reduce the likelihood of a breach occurring and make the structure safer
Removal of all fish from Paul’s Pond
The removal of all silt in a 30 metre radius from the valve chamber. The silt will be deposited behind the willows at the south end of the Paul’s Pond in straw bale enclosures.
Removal of all vegetation growing out of the upstream face of the dam wall. Stumps to be treated with glyphosate to prevent regrowth.
Removal of all trees on the downstream face of the dam to the point of the dam toe. The end result will be a grass banking to facilitate easy checking of the dam structure for leaks and to prevent tree roots compromising the dam structure. All timber to be removed from site, brash chipped and removed as well.
Draining Paul’s Pond to enable works to be done on the dam wall. If the leaks are high up it may be possible to avoid a complete drain.
Excavate behind the dam wall in the vicinity of the valve chamber to locate the leak points
Apply puddling clay and maybe a cement face to the leak areas and backfill with the excavated soil.
For the works to take place the following measures will also be employed: –
Closure of footpaths in the areas of the tree works.
Closure of paths in the vicinity of the dam repairs.
A temporary enclosure at the south end of the Breary Marsh next to the bridleway entrance from the A660. Welfare facility to be installed, puddling clay stored, temporary stock pile area for felled timber, stone for path remediation works and creating temporary stream crossing.
Removal of some trees on the access route to the dam from the above enclosure
600mm pipe covered with crushed stone to enable a safe vehicle crossing at the horse ford in Breary Marsh (On access route to dam)
Ecologist to be employed to remove crayfish where the silt traps are to be located below the valve chamber culvert, where the vehicle crossing is to be constructed and from the false stream that runs from the valve chamber to the spillway water channel (this will dry-up when the leak is repaired).”