Thursday, December 11, 2008

River Channel in Ladywell Fields

We've been informed that the new river channel in Ladywell fields has run dry. It seems that the weir was breached on Sunday, the river dried up very quickly and sadly many fish have been found dead in the channel.

It is not entirely clear how this has happened, but Council officers believe a combination of causes may have contributed:
  • High flows over the previous weeks weakening the dams structure by dislodging smaller rocks
  • Vandalism - some smaller rocks may have been taken - quite possibly for garden rockeries….
  • The Environment Agency's river works - a huge amount of debris has piled up on the weir following the river works. This will put greater stress on the weir, and it is possible that a large trunk flowed down and dislodged rocks in the weir.
Although the site of the breach is quite small, the result has been severe.

The weir, which was part of the recent Quercus works, was built to the Environment Agency's specifications, and strengthened in the spring, as they were not happy with the initial specifications. A further review was planned for the coming spring.

Council officers are working together with the Environment Agency and their works contractor to put this right. They hope to get an interim solution in before Christmas, and to rebuild the weir early in the new year. They have been advised to stick to the same approach, but that the weir will need to be considerably larger - 5+m in the direction of flow, so that a riffle effect is created rather than a waterfall, and larger boulders will also be used.

Notices have been put up in the park to explain what has happened.

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