Issue: Habitat scale influences - Water Quality (for surface and groundwater) - Thermal pollution
This is an issue under the Inland waters theme of the Data Reporting System.
Water behind dam walls is often warmer at the top and colder at the bottom. Because the water discharge points tend to be at the bottoms of the dam walls, discharged water is colder downstream than would normally be expected, especially in summer.
Water colder than the natural river temperature can limit fish breeding and promote disease among fish. Lower temperatures will also reduce the rate of primary and secondary production in riverine food chains.
- IW-23 Mapping of water temperature depression due to dam releases
Mapping of water temperature is a direct measure of this pressure.