River Chess Association

Upon first glance, it seems peculiar that the Chesham stretch of the River Chess is dry in Winter; our cooler, wetter season. This is because, unlike many UK rivers, chalk streams like the Chess are fed by water stored in the chalk rock below our feet. It takes a long time for rainwater to soak down through the soil into the chalk, so the flows of the Chess are a reflection of the amount of rain that fell over the previous Winter.

Wet winters are essential to ‘recharge’ the aquifer (the store of water in the ground) to keep the river running. And it’s the rain that falls between October and March that determines how high the groundwater level reaches and how well the Chess flows all year round. Due to some unusually dry weather before and at the end of Winter 2014-15, the recharge season was shorter than normal, with the majority only happening between December to February. March 2015 was particularly dry, with very little rainfall reaching the aquifer, which meant that the recharge season ended much earlier than normal.

In a normal year groundwater levels reach their peak in Spring and then start to fall over Summer and on into Autumn, as the rain that falls then is largely evaporated or taken up by plants and doesn’t make it to the aquifer. The springs that supply the river gradually stop flowing and the top end of Chess begins to dry up. This is all part of the natural cycle for chalk streams, but this year because groundwater levels were lower than usual in the Spring the river has dried down further than would normally be the case. The river won’t start to flow through Chesham again until this Winter’s rain starts to recharge the aquifer and unfortunately, if we have a dry Winter this year, the river will suffer even more come Summer 2016.

Whilst weather patterns play a major part, we mustn’t forget that water companies take a huge amount of water out of the same aquifer to meet local residents’ and businesses’ needs. Both Thames Water and Affinity Water have pumping stations locally (at Alma Road, Hawridge and Chartridge) where water is taken from the chalk so that we can brush our teeth, use our power showers, clean our cars, water our gardens and the many other tasks that are part of our regular lives. The more efficient we are with the water we use, the more water can be left to flow in the river.

We’d like to thank the members of the public who carried out fish rescues from the drying stretches, taking bullheads, minnows and sticklebacks in buckets down to the Chess at The Moor. We tried to save as many as we could, but sadly we know that thousands of small fish perished as the river dried.

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