A new multi-functional wetland is being created at Harrison’s Holme between the River Bain and River Waring near Horncastle, Lincolnshire, as part of efforts to restore natural chalk stream processes and improve floodplain connectivity.
The project will reconnect the rivers to 1.4 hectares of floodplain, restore natural flow pathways and create a mosaic of wetland features designed to enhance water storage, ecological health and local amenity value.
Wetland restoration supports chalk stream recovery
The scheme forms part of East Mercia Rivers Trust’s (EMRT) wider ambition to restore the Bain and Waring catchments through its chalk streams programme.
CBEC eco-engineering, part of the RSK Group, has delivered surveys, modelling and design assessments to support EMRT in developing an effective and resilient wetland design.
Megan Annetts, Consultant Geomorphologist at CBEC eco-engineering, said detailed land and river surveys were essential to understanding how the chalk streams currently behave and how the floodplain could be restored to function more naturally.
Design informed by geomorphology and hydraulic modelling
Geomorphological assessment played a central role in the project, providing insight into sediment movement, channel stability and the influence of historical river modification on the current landscape.
This understanding directly informed the wetland design, indicating where floodplain scrapes, backwaters and wetland cells would deliver the greatest ecological benefit while working with natural river processes. The proposed scheme includes 752 m² of bank regrading, 2,377 m² of wetland scrape features, 109 metres of swales and 288 metres of bunding.
Hydraulic and geomorphological models were used to test design options and assess how water would behave under current and future climate scenarios, ensuring the wetland increases water storage without creating unintended flood risk.
Nature-based solution delivering biodiversity and resilience
The restored floodplain will provide improved habitat for species such as brown trout and water voles, while increasing wetland diversity and enhancing the site’s overall ecological condition.
All construction material for the wetland will be generated on site through excavation, reusing approximately 742 m³ of existing ground to form the new wetland features and minimise environmental impact.
High-resolution surveying and visualisation support engagement
A topographic survey was carried out using real-time kinematic (RTK) GPS equipment to collect centimetre-accurate elevation data, enabling the creation of detailed 3D site models. Drone imagery and orthophotos were also used to produce visualisations showing how the completed wetland will function.
These visual tools have supported stakeholder engagement alongside partners including Lincolnshire Wildlife Trust, helping communities understand the benefits of the project.
Integrated approach to environmental and heritage protection
Additional desk-based land contamination assessments by RSK Geosciences and heritage impact statements by Headland Archaeology have informed the design process, ensuring environmental and historical assets are protected during construction.
Sam Valman, Project Manager at EMRT, said the technical design work and visualisations were critical in securing permissions while helping communicate the project’s value to the wider community.
The project demonstrates how process-led, nature-based design can restore chalk stream function, deliver measurable ecological gains and improve climate resilience within a highly modified river landscape.
