The two big challenges on the restoration this year were always going to be disposal of accumulated water around the site and forming and shaping earthworks in potentially soggy ground. Thus at the start of March top of everybody’s wish list was a lengthy spell of dry weather. Four work parties in, our wishes seem to have been granted with the result that channel shaping is well in front of programme. However such were the groundwater levels in the channel during the March work parties that the decision was taken to postpone the start of lining/blocking until May. The expectation of dryer conditions later in the year and the fact that channel can be lined much quicker than it can be shaped should enable that programme item to catch up.
Both work parties occupied four days, the first of which was occupied mainly with pumping out the channel. As with all restoration there is a steep learning curve, and we are learning! The main problem is not getting rid of the large quantities of water in the channel at commencement of operations, but rather the disposal of the more modest volumes of seepage subsequent to that. The construction of a couple of temporary dams, and a number of sumps in the bed of the channel and a couple of extra pumps is helping.
During the first weekend, the main channel shaping work was in area of old LAF dam. Having reduced the bed to grade, the narrow offside bank was shaped using a combination of large and small diggers and hand finishing. During course of this work, the access slope in the area of the location of the Hell Hole was filled to the final bank profile. The month’s second session saw shaping activity move to area of the oak tree. Here the second access slope was also filled in. By the end of work 120m of channel was ready for lining/blocking.
Most of the pumping and shaping activities have been done by the machine gang. The lining gang have also been in action doing the all-important preparation for the start of their major task. In summary, there are sufficient lining materials cut to size and blocks located at strategic locations to enable work to start next month.