Slow the Flow - Natural Flood Management

Hardcastle Crags is a well loved beauty spot in the South Pennines with more than 160 hectares of woodland and grassland. We aspire to be the demonstration site for Natural Flood Management best practice. Most of what we do is achieved with the help of local volunteers and through partnerships.

The background

The National Trust is working with partners including the Environment Agency and Slow the Flow Calderdale to install wide range of natural flood management interventions (NFM) in the Hardcastle Crags Estate. Many of these NFM interventions will involve using natural resources such as trees trunks and branches to create leaky dams in the streams that run through the woodland. Leaky dams reduce the speed at which water runs through the woodland into the River.  

NFM is also a key objective of our woodland management plan.  We will also implement a monitoring scheme that will help measure the success of these NFM interventions. As a significant landowner in Calderdale we feel it is important to play our part in reducing peak flows of water that often impacts communities downstream.  The leaky dams will also provide important deadwood habitat for fungi and invertebrates. Tree felling to produce the materials for the leaky dams in itself will help to create wet woodland and also increase light levels on the woodland floor to benefit species such as butterflies and improve the rate of natural regeneration for a wide range of different trees. 

Many hands make 'slightly' lighter work
A selection of volunteers - lending a hand to help the valley
Many hands make 'slightly' lighter work

An update

National Trust staff and volunteers, have now been working with Slow The Flow Calderdale since late 2016 and they've now built well in excess of 130 leaky woody dams using over 100 volunteers. The volunteers meet twice a month and typically build 3-5 new dams at every session.

Early indications are that these leaky woody dams in Hardcastle Crags are working to slow the flow and reducing the impact of flood water finding its way down the Calder Valley. 

Formal results of how much water has been slowed will be published in 2018 assuming it rain sufficiently to measure the success of this pilot project.

Slow The Flow is made up entirely of volunteers who receive no payment whatsoever. Their desire is simply to reduce the likelihood of future flood events in the Calder Valley and beyond. This is a tangible and very worthwhile way of helping to keep the rain out of the towns and villages we all work and live in.  
 

Slow The Flow continue to work with Calderdale Council and The Environment Agency to identify other areas which would benefit from the installation of these leaky dams. If you know of such an area, please do get in touch so Slow The Flow can add it to the working list of potential sites which they are developing with Calderdale MBC. Their desire is simply to reduce the likelihood of future flood events in the Calder Valley and beyond. This is a tangible and very worthwhile way of helping to keep the rain out of the towns and villages we all work and live in.  

If you would like to get involved with Slow The Flow Calderdale, please visit their website www.slowtheflow.net for more information. There are plenty of opportunities to work with us and make a difference to our community and to our ever changing environment.

lets pull together
volunteers work together to move large trunk into place for leaky dam
lets pull together