Delivering natural flood management solutions in the Calder Valley – Norland Moor feasibility and concept design

Working with Calderdale Council, we are supporting the design of Natural Flood Management (NFM) features on Norland Moor above the town of Sowerby Bridge.

The project aims to:

  • Slow the flow: by increasing resistance to the water flow – for example, by maintaining rougher vegetation or blocking grips on moorland.
  • Store water by using, and maintaining the capacity of, ponds, ditches, runoff attenuation features, channels or land.
  • Reduce water flow connectivity by interrupting surface flows of water – for example, by planting buffer strips of grass, shrubs or trees.
  • Increase soil infiltration: better draining soil will make saturation less likely, potentially reducing surface runoff.
  • Encourage evaporation from vegetation and soil which can also make space for water.

In addition to the flood management interventions, several other key benefits have been identified. These include increasing the wider ecological benefits within the moorland site via re-wetting and moorland management techniques, as well as recreation management with the restoration and maintenance of eroded footpaths and cycle tracks. The NFM interventions will look to aid these additional key benefits of the site.

How are we doing this?

To meet these objectives our ecologists and NFM analysts carried out site and desktop surveys of Norland Moor to identify key locations where interventions could potentially aid NFM and ecology improvements. A bespoke Norland Moor hydrological and ecological intervention plan was developed to identify these potential locations for Calderdale Council.

Leaky dam diagram
Example of a leaky barrier design

Several of the smaller recreation and ecological interventions have since been successfully implemented on the moor by Calderdale Council using local volunteering groups. For a selected few NFM interventions, we supported Calderdale Council further by developing concept designs. These included Runoff Attenuation Features and Leaky Barriers which were designed to slow and store surface water flows from the moorland accessing Maple Dean Clough.

Each design included a summary of the proposed works, specific construction details and risks, maintenance considerations, potential environmental impacts as well as flood flow benefits. We used these along with detailed design sketches to complete the ordinary watercourse applications on behalf of Calderdale Council for the interventions which have since been approved.

The next stage of the project will see our NFM engineers meet with Calderdale Council on site to discuss the future design and implementation of these features.

 

If you would like more information about this project or would like any advice or assistance on NFM feasibility, concept design or ordinary water course consent, please email Ryan Jennings, NFM Analyst, JBA Consulting.

Natural Flood Management

JBA has extensive experience in natural flood management (NFM) and we are one of the leading consultancies in this field in the UK. We are also making significant technical contributions to two of the major NERC funded NFM Research Projects (Q-NFM and LANDWISE-NFM). The scope of this research has been co-designed with project partners: NERC, Defra, the Environment Agency, Scottish Environment Protection Agency, the Welsh Government and Natural Resources Wales to improve our understanding of the effectiveness of different NFM measures across a range of flood risk scenarios, thereby addressing some of the known knowledge gaps.

Want to know more?

We provide numerous services across the full NFM spectrum of topics, including:

  • NFM Research and Assessments
  • NFM Potential Mapping
  • NFM Hydraulic Modelling
  • NFM Surveys
  • NFM Engagement
  • NFM Training
  • NFM Barriers and Enablers
  • NFM Design/Engineering
  • River Restoration
  • Geomorphological Assessment
  • Ecological Assessments
  • Fisheries Science
  • Fish Pass Design
  • Habitat Surveys
  • Hydraulic Habitat Modelling
  • Water Framework Directive (WFD) Assessments
  • River Restoration Feasibility and Design Studies

We have over 10 years experience in natural flood management, and led the consortium that worked with the Environment Agency to publish the Working with Natural Processes Evidence Base in 2017.

Email Steve Rose, NFM lead, for more information.

You can also find out more on our Natural Flood Management webpages.



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