How you can help the National Trust learn more about flooding at Hardcastle Crags

Fixed point photography posts will mean experts can study changes in river levels.

The National Trust and Slow the Flow are asking the public to get involved and help track the changing river levels at Hardcastle Crags. As part of their ongoing work to slow the flow of water in the woodlands and the wider Calder Valley, fixed point photography posts have been installed alongside many paths. The photos will help experts study how water behaves in the woodland and how streams respond during periods of heavy rainfall. The work’s been ongoing following a number of large-scale flooding events, which devastated the Calder valley, including on Boxing Day in 2015.

The photography posts are also marked on a special map, which guides visitors around the woods to explore more of the natural flood management work that’s been put in place. In total, more than 600 leaky dams have been installed, mostly by volunteers led by Slow The Flow and funded by the Environment Agency and Calderdale Council. These leaky dams allow water to soak more slowly into the woodland floor, helping to reduce the peak of floods further down the valley.

Trail Map for Hardcastle Crags. Copyright National Trust

National Trust Project Manager, Jess Yorke, said

“we’ve already made huge progress at Hardcastle Crags by installing hundreds of leaky dams in the woodlands with our partners Slow The Flow and the Environment Agency. Now we need people to get involved and help us learn how that work is making a difference. By safely taking photos from the photography posts, especially during periods of heavy rainfall, and submitting them, the public can play their part in helping us study the effects of the leaky dams, it’s also a great activity on a post-Christmas walk, and all the family can get involved”

Adrian from Slow The Flow, said,

“We’ve already had hundreds of volunteers help us build leaky dams and reduce the flood risk, now it’d be great to get volunteers to help us study the effects too. We’re already collecting plenty of scientific data from our work, but photographs from fixed points will also really help us understand the difference the work we’re doing is having.”

Leaky dams at Hardcastle Crags. Copyright National Trust Images/Paul Harris.

The fixed points can be found on the Mill Walk, Railway Walk and near Gibson Mill. All of the points are listed on the Natural Flood Management map which is available from Gibson Mill and at the start of the track near Midgehole Car Park. Photographs can be submitted via email to or by tagging Hardcastle Crags or Slow The Flow on social media. Please make sure there are no people in your photographs and ensure they are in landscape orientation.