Ben Gill is being reconnected to the River Ehen.

Engineering work on the weir of Ennerdale Water in the 1950s raised the level of the lake, increasing its storage capacity and ensuring a more secure potable water supply. As part of this work, one of the tributaries of the River Ehen (Ben Gill) was diverted to Ennerdale Water via pipeline. As a consequence there has been a reduction in the volume of sediment entering the River Ehen as well as a change in the river’s hydrological regime.

The River Ehen is a Special Area of Conservation and supports the largest viable population of Fresh Water Pearl Mussels left in England. The population, however, is ageing and declining and urgent action was required to prevent their extinction. A major cause of this decline has been identified as habitat degradation, particularly river impoundment which affects flow regimes and channel geomorphic conditions. A change in hydraulic and sedimentary conditions can affect both adult and juvenile mussels. As a result of a review of abstraction consents under the Habitats Directive, United Utilities are to reconnect Ben Gill to the River Ehen.

The project involves the recreation of the original Ben Gill channel, the construction of a section of reinforced concrete training walls, and the construction of a new access bridge.

PaSCoE have completed the design and work has started on the reforming of the Ben Gill Channel, working closely with the Environment Agency and Natural England.

Hayeswater Reservoir is being returned to a natural tarn.

After more than 100 years of public service Hayeswater Reservoir is being restored to the natural mountain tarn it once was. Dammed in 1908 to provide drinking water to communities around Ullswater the reservoir was declared surplus to requirements in 2005.

Hayeswater reservoir is located in a high mountain valley about two kilometres south east of Hartsop; at the head of Kirkstone Pass with access via a mountain track. The difficult access required the design and installation of a modular steel bridge to cross the existing stream. All parts needed to be relatively lightweight utilising bolted connections with the abutments formed from timber sleepers.

The project team of United Utilities, PaSCoE, and Eric Wright Civil Engineering have worked very closely with the Environment Agency, Natural England and the Lake District National Park Authority to deliver the project with minimal environmental disturbance.

The project includes the removal of the concrete and stone weir dam, construction of a new river channel to recreate the flow of the original tarn’s natural outflow into Hayeswater Gill, and installation of a new footbridge along the route of a public footpath. Step pools will be created within the new channel to allow ecological processes and fish passage to re-establish.

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