The hydropower opportunities and environmental sensitivities map identifies almost 26,000 locations where a hydro power turbine could be located. Together, these sites could generate enough electricity to power up to around 850,000 homes and produce 3% of the country’s 2020 renewable electricity needs. In reality, however, only some of these sites could be exploited due to environmental sensitivities, as well as practical constraints such as access to the electricity network.

The new maps help to identify areas where hydro power could make a positive contribution to the local environment, and sites where it is less appropriate.

The report found that a sensitively designed hydropower scheme that includes a fish pass could improve the local environment as well as generate electricity in over 4000 sites. These opportunities are particularly concentrated on rivers such as the Severn, Thames, Aire and Neath.

With the government soon to offer subsidies of up to 20p for every kilowatt hour of electricity produced, a medium-sized scheme that typically generates enough electricity for about 32 homes, could receive around £25,000 a year. Average set up costs range from £100,000 to £150,000. But, the Environment Agency stressed, only schemes that were well designed and had no negative impacts on the river wildlife or the local environment would get the go ahead.

“Some hydro power schemes have the potential to deliver low carbon electricity and improve the local environment for wildlife, for example by improving fish migration. But there will inevitably be some sites where the risk to the environment outweighs the benefits of power generation,” said Tony Grayling, Head of Climate Change and Sustainable Development at the Environment Agency. “With Government’s new feed-in tariff for renewably generated electricity, hydropower could become an attractive income generator for hydropower developers, if environmental safeguards are met.

“The report recommends that fish-friendly design needs to be incorporated in all schemes, and that grants for fish passes could help to unlock the potential of small scale hydropower in England and Wales.”

In particular, the report found:

• A total of 25,935 small scale hydropower opportunities.

• Over 4000 win-win opportunities, where a hydro power scheme with a fish pass could deliver an improvement in the local environment as well as renewable electricity.

• Small scale hydro power at the sites identified could in theory generate up to 3660GWh electricity per year, or about 1% of the country’s predicted 2020 electricity demand. The real potential is significantly less due to environmental and practical constraints.

• Hydro power hotspots, where win-win opportunities exist on the same river or close by were identified in several areas, including the Rivers Severn, Thames, Aire and Neath.

• Around half the sites identified were deemed to be highly environmentally sensitive for hydropower due to impacts on river ecology. Extra fish-friendly measures would be required in these locations.

“Small scale hydropower is potentially one of the most cost-effective means of producing clean, green and home grown renewable electricity,” said Lord Hunt of Kings Heath, Minister of State for Energy.

“It is clear that recent advances in technology, reduced equipment costs and financial incentives like the new feed-in tariffs will provide further opportunities for communities to harness the power of our rivers and streams.”

An interactive map is available to view on the Environment Agency website, and lists the number of hydro power opportunities in each region, as well as the total power potential and the environmental sensitivities to be considered.

The full report and the interactive hydro power maps are available to download at