Skip to main content

NECR545 Information on How to Deliver and Assess Engineered Logjams for Nutrient Mitigation (NECR545)

This report is included within Part 2 of a series of reports on nutrients.

This Framework document advises on the Engineered Logjam (ELJ) mitigation measure and what is required to achieve scientific certainty for nutrient neutrality (NN). It does not consider whether it is possible and how to achieve practical certainty that the measures can be secured.

This Framework sets out how to determine a scheme specific nutrient efficacy reduction through a combination of baseline and post-implementation monitoring as not enough evidence was found in Part 1 (the literature review) to determine precautionary efficacy estimates without monitoring. Although this framework focuses on ELJs in the context of NN mitigation, there can be potential synergies between different mitigation solutions.

Implementing a system of multiple Nature-based Solutions (NbS) to achieve NN will provide greater nutrient reduction benefits through floodplain reconnection, reduced velocities, and increased contact time between nutrient rich flows and sediments to which they can bind. Capitalising on the synergies between NbS to achieve NN will allow for reduced nutrient loads from each scheme to be stacked together to achieve more nutrient credits than any one scheme would mitigate. The load reduction benefits of synergistic interactions between NbS would need to be addressed on a case-by-case basis for realistic credit generation.

In addition, NbS have the potential to provide many wider benefits. These wider benefits are also considered as part of the feasibility process which may support other biodiversity and societal net gain ambitions as part of the planning process.

Downloads available for this record

File Uploaded
NECR545 Information on How to Deliver and Assess Engineered Logjams for Nutrient Mitigation, PDF, 918.8 kB 2024/03/06