Written evidence submitted by (FLO00005) John Markwick.

Although I am living in on the edge of the , outside , I am aware that the levels of the Severn in Wales directly affect river levels downstream from Shrewsbury to Bewdley and beyond. I was member of the Severn Trent Flood Defence Committee for 10 years. This has given me a broader view of Flooding Problems both in Wales and also on the Trent and Avon.

In the Upper Reaches of the River Severn a was constructed, for the retention of water by Severn River Authority, under ‘The Clywedog Reservoir Joint Authority Act 1963’. The Reservoir opened in 1968.

The publicity was that ‘The Reservoir would regulate the flow of water in the River Severn and reduce flooding in the Upper Severn Valley’. Unfortunately the Clywedog Reservoir Joint Authority Act sets out strict rules for the discharge of water during the winter months with no discharge during the summer months, except for keeping up levels at Bewdley where the Water Authority draws off water for human consumption. This means that it can not act effectively as a flood control reservoir as was promised.

Over the last 52 years since the Dam was opened weather patterns have altered and the rules set out in the Clywedog Reservoir Joint Authority Act 1963 are no longer fit for purpose.

It is not in the interest of the Severn Trent Water Authority (now Hafren Dyfrdwy)to have them amended. To Change the Act would require agreement of all parties including the Welsh Assembly Government.

The problem with the reservoir during flood conditions is that the freeboard is insufficient to hold sufficient water after a heavy rain fall. The Dam fills very quickly and then overtops. The Managing Authority then has to release more water to prevent damage to the dam’s structure.

As all flood authorities now have a better grasp of the forthcoming weather conditions and the EA has ample notice of what to expect. So a larger discharge could have been made but for the Regulating Act. No Environment Agency Officer or NRW Officer is prepared to break these conditions. This means that there is no control of the floodwater coming from the reservoir. These Officers, when questioned about the management of the Dam, always go back to the Act and do nothing.

The second problem is that as soon as the storm passes the Managing Authority then discharges water from the dam. This is on top of the already over charged River Severn. This of course means that the Severn is running high for a considerable time adding to the excess of floodwater down stream towards Bewdley and beyond.

With the modern flood level gauges, that are online, I have been able to follow this surge as it passes the level gauges from to Welshpool and beyond. I can also see the effect from my window.

If the Severn is to be managed properly to ‘Protect People & Property from Flooding,’ then a start has to be made at the confluence with the freeing up of the dam controls from the current out of date Act!!

The second Reservoir that affects the River Severn is the Vyrnwy Reservoir. This was built to serve Liverpool in the1880s it has never had a flood control mechanism. The outfall is too small to affect a fast discharge during a flood. However a larger outfall could be constructed, to enable water to be discharged before the heavy rain arrives, thus balancing out the flow from the reservoir. Both the Rivers Vyrnwy and Severn meet at the Country boundary causing a faster flow towards Shrewsbury. It would be possible to hold some of the water back on the confluence, at Melverley by flooding farm land without affecting property. There was also a plan to construct a further control nearer Shrewsbury by flooding agricultural land.

In the Upper Severn the growing of Maize in the floodplain for the making of silage for winter feed also affects the ability of the fields to hold water. A Maize crop is very much an industrial crop. Heavy machinery is used to plant and harvest the crop followed by the spreading of liberal quantities of slurry on the bare fields.

The effect is to seal off the ground; no flood water can be absorbed and anything on the fields are then washed into the river. For ecological purposes the growing of Maize in the floodplain should be banned and any other crop should be followed by the sowing of grass.

Our floodplains are a great reserve for wild life but only if the main crop is grass – not industrial maize.

I have always supported the idea of paying farmers for the use of floodplains for the storage of floodwater. However over the years development of individual properties has taken place in the floodplain. This means that private properties have also to be compensated or, as in Holland, individually protected with a safe driveway to their property.

14th April 2020