Tuesday 30 April 2013

Repairing the bank on Lake Windermere

As part of United Utilities work on preventing flooding in Bowness-on-Windermere  a new pipeline has been put in place that runs through part of Cockshott Point and out into the lake. In order to do this a section of stone revetment, that helps protect the bank, had to be removed so it was our job to reinstate it.

Before starting work

To make sure everything stays in place we decided to bring in some large "keystones" to create the bottom course. These will help keep the rest of the revetment secure in the event of the lake rising and falling and potentially undermining the bank.

Moving the keystones down the bank

As the water level can rise rapidly after melting snow or heavy rain it was essential that we got these keystones in quickly. To help speed up the process we bought in a mini-digger to dig out the initial trench, move soil around and help shift some of the larger keystones.

Digging the trench

It wasn't too long until we had the line of keystones in place.

Putting in the keystones

With this done the next job was to get our levels right. With four people all working at slightly different speeds across a large section it's quite easy to wander off line a bit. So we set up string lines to keep everything even.

Getting the levels right

The revetment is built up in the same fashion as a drystone wall where a series of courses are created and each stone overlaps that underneath it. In just a few days we were starting to make good progress up the bank.

Making progress

After another day, or so, we reached the top of the bank. To finish the top course we used some good, deep, stones and tightened them to the courses in front.

Getting higher up the bank

With all the stonework in the ground it was just a matter of filling in the gaps with soil and seeding over the area to prevent the soil washing out.

 Filling in the gaps

Update: A photo of the work two and a half years later, taken early October 2015...

After some "bedding in" time

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