UKTAG first published guidance on the classification of ecological potential in 2008. This guidance included lists of mitigation measures relevant to the range of adverse impacts on the water environment that the different water uses can have. For impoundments for the purposes of water storage and supply, 12 mitigation measures were identified. These recommendations supersede the existing guidance on assessing whether a measure is in place and adequate for 3 of these 12 mitigation measures, and have been determined following consultation and a stakeholder workshop throughout 2013.
Mitigation measure 2: Manage the volume and timing of flow releases to trigger fish migration
Mitigation measure 5: Establish and appropriate baseline flow regime
Mitigation measure 8: Provide flows to move sediment downstream
The recommendations in this document are intended to help UKTAG’s member agencies design appropriate mitigation flow regimes for good ecological potential in rivers designated heavily modified because of the impacts of water storage and supply. They provide guidance on how to:
- identify which of a number of ecologically important components of river flows (flow building blocks) are likely to be ecologically beneficial at the site concerned; and
- determine the appropriate magnitude, duration and frequency of the relevant flow building blocks, taking account of the ecological characteristics of the site concerned.