Drought & it’s effects on the Canal

As widely publicised by the Met Office this summer there has been a prolonged period of low rainfall dating back to last November, with most of England and Wales officially classified as being in drought.

Met Office data widely published stated that we (in the south and east of England) experienced the driest 8-month period since 1976, the driest July since 1911 and broke the high temperature record for England in July. Other waterways such as the Thames were also beginning to suffer from low water levels and starting to put in place similar water saving methods to us, requiring boats to double up in locks and closing locks to navigation at night-time. Canal and Rivers Trust closed the Peak Forest Canal in May and placed an increasing number of lock use restrictions on parts of their network throughout the summer.

That some parts of the Basingstoke Canal were and are still short of water now in October is therefore not surprising – there was simply not enough water coming in to keep all the Canal supplied at normal operating levels.

This year has clearly been an exceptional year as we have not had to close Mytchett pound (section between Deepcut and Ash Lock) to navigation since 1990 due to water shortages.

Water levels initially held well in the Hampshire pound (section between Ash Lock and Greywell) of the Canal and whilst water was still coming into the Canal from the aquifer-fed springs at Greywell and Broad Oak, we were able to still pass water down into the Mytchett section of the Canal for a time.

Near the end of June, the Deepcut and Brookwood lock flights were the first to close without enough water to sustain them and Ash Lock followed not long afterwards.

By mid-July the daily amount of water we were able to pass from the Hampshire pound into the Mytchett pound was being exceeded by the daily amount being lost – mainly to evaporation and transpiration and this section of canal began to drop off rapidly meaning that soon we had to stop powered boats from using it and then even unpowered boats such as canoes and kayaks.

Towpath users would have noticed the large shelves and beaches that appeared where there used to be water and our freshwater mussels getting an unwelcome exposure to the air. Emergency planning was put in place in consultation with the Environment Agency and Natural England to allow us to manage for these unprecedented conditions, considering for example how we would manage struggling fish with not much water or oxygen. Thankfully the fish took care of themselves and found deeper water areas and we finally had some rainfall.

At the time of writing, the water levels have come up enough in the Mytchett pound to reinstate unpowered boat use but are still some way off the levels needed to allow powered boat use that needs deeper water to prevent propellors becoming fouled and damaged. The Hampshire pound has remained at good navigable levels all summer and of course Woking has remained at normal levels supported by the back pumping of water. We are however not at the end of the drought yet; aquifer and reservoir levels have continued to decline generally across Britain, so unless we have a prolonged period of rainfall over winter to replenish aquifer levels, we expect that we could have another difficult season next year.

While it has been a trying summer for all waterway managers, the herons and kingfishers took full advantage of the clear shallow waters, with food literally on a plate!

Fiona Shipp
Basingstoke Canal Authority