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calculated.  This shows that for the 1970's the Tarrant lost 60 l/s less flow than in the later period when, coincidentally, the Shapwick boreholes were operational.  This last stretch is an important salmon spawning area (Salmon Action Plan Consultation Document by EA March 2000).  To determine if this stretch is 'perched' the EA drilled three wells around the lower river reach in 1997.  After initial problems with the data logging equipment, analysis has proceeded slowly due to other higher priority work.  In addition the EA makes regular flow measurements and observations along the river which are supplemented by bi-monthly reports on river flow conditions at other points by RTPS members.

The consultant's report included a section on water management as follows:
"Locally, changes in water control, the abandonment of water meadows, the destruction or neglect of hatches and the drainage of land adjacent to the river may have changed the visible regime of the river. The flow within the river, the number of litres per second which are passing a particular point, will not permanently be altered by features such as weirs or hatches. The same flow can be carried by shallow fast flow as by deeper but slower flow. What is seen by the lay observer is not the depth of flow, but the overall ecology and amenity value of the river which is related both to depth and to the velocity of flow.

Measures to increase water depths by the construction or rehabilitation of weirs and hatches would be hydrologically acceptable along the reach of the Tarrant where the river is gaining flow, subject to their not increasing the flood risk. A suitable water management plan would need to be evolved in consultation with advice on how the overall ecology of the river would be likely to respond. These measures would not require actual flows to be augmented, but would only manage the depth and velocity of the flow."  'The Environment Agency do not necessarily agree that these sort of modifications in the river channel would be beneficial to the flow regime, and any such modifications would require consent from the Agency.'

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