Trowell Natural Flood Management

Project Overview

The Environment Agency provided funding to introduce natural flood management (NFM) installations across the UK. NFM measures are seen as a cost-effective alternative to typical hard engineered flood defences, that can be installed on a much wider scale and provide increased flood resilience to a greater number of communities. Nottinghamshire County Council (NCC)  were awarded a funding package to install NFM measures around the Boundary Brook in Trowell, Nottinghamshire, which has a history of flooding onto the A6007 and the adjacent housing, when the volume of water overwhelms the installed culverts.

The Challenge

EMEC were instructed to lead the identification, design and delivery of the NFM measures within the Boundary Brook catchment area. The land adjacent to the Boundary Brook is owned by multiple landowners, who had a variety of allowances and restrictions. Designs were generated in collaboration with the relevant landowners, and NCC, to ensure all parties were satisfied, and significant benefits would be realised. Implementation of the designs involved construction on public and private land, and therefore, relied on permissions from landowners to allow works to be delivered.

The Solution 

Two separate areas were selected for NFM modifications. Both areas were adjacent to Boundary Brook and offered scope for significant improvements. The designs were tailored, dependent on considerations from both the landowner and NCC, and were finalised along with a delivery window. Relevant permissions were secured, which included diverting a public footpath.

Pit Lane Recreation Area

The inherited area was unkept and overgown, with a significant Himalayan Balsam presence, and footpath damage due to previous flood events. Early work included Balsam clearance, to remove the invasive species and mitigate further spread. Land modification work began in September 2025, and included tree felling and installation of leaky barriers, but predominantly focussed on creating a wetland area, designed to create water pathways and significantly increase the water storage capacity, during high rainfall events. By holding water up stream, the volume of water and rate of flow is lessened, mitigating the risk of overwhelming the culverts downstream. Water then seeps back into the brook, via permeable ground, at a slower, more manageable rate. Moreover, the wetland design includes a variety of habitat and ecological improvements, with various hibernacula, ponds and bunds to installed to increase the areas biodiversity. The damaged section of footpath was restored, improving the accessibility for the public.

Pit Lane After

Farm Field Floodplain

The design for Farm Field floodplain focussed on creating a new, meandering channel for Boundary Brook and reshaping the floodplain, to increase its effectivity. Historically, Boundary Brook ran straight, before entering the culverts below the A6007 bridge. A new meandering channel was dug through the existing floodplain, aimed at slowing the flow, increasing the water holding capacity and allowing better utilisation of the floodplain in flooding events. A hard barrier closed the original brook pathway and diverted it into the new channel. Furthermore, groundworks were carried out on the adjacent banks to encourage water to pool in the floodplain, opposed to run directly to the culvert, in times of high rainfall. A series of ponds were included in the upper section; holding water and leaky barriers were installed throughout, to slow the water flow.

Farm Field Before

Farm Field After

The Outcome

This project is a great example of the benefits of collaboration with Nottinghamshire County Council and how NFM installations can provide both greater flood resilience and ecological benefit. The two distinguishable areas highlight EMEC Ecology’s adaptability in design when working with a range of different landowners, finding solutions when under varying considerations and restrictions. The site has welcomed local councillors and members of the flood action group, who saw the project as a positive step in mitigating flood risk, and improving the biodiversity of the local green space.

Quote

“The Trowell NFM project has been successfully delivered by EMEC Ecology with a wide range of Natural Flood Management interventions installed. The interventions will help to reduce downstream flood risk whilst also enhancing the local environment though habitat creation. EMEC Ecology  have brought a wealth of knowledge to the project and have used their specialist expertise to design and deliver interventions which suit the local landscapes, benefit wildlife and store water during high flows.”

Dr Josh Wells – Principal Officer – Flood Risk Management, Nottinghamshire County Council

*Photography and Drone shots supplied by Nottinghamshire County Council