Flood Reduction NFM Scheme Retrofit Flow Monitoring

Radio Data Networks Limited [RDN] is proud to be working with Utilites, Local Government and the Environment Agency on NFM flood reduction schemes, to “slow the flow”, reduce flooding and the operation of CSO overflows.

As a UK based business, with in house design and manaufcature, we are able to provide the bespoke solutions that are often required to face up to the challanges of monitoring in both urban and remote areas, where cellualr coverage can be sparce and unreliable.

Natural Flood Management [NFM] is a modern, low carbon approach to reducing flooding and facing head on the threat from Climate Change.

NFM comes in many forms from roadside swales to forestry plantations with trees. The objective of NFM is to slow the flow, plus absorb rainfall before it hits a watercourse or combined sewer network, thereby reducing its peak flow and the risk of spills, pollution and flooding.

Aside from the flood benefits, NFM features can help create a diverse environment for a whole variety of plant and animal species called biodiversity and helps to improve the resilience to drought of nearby trees and shrubs, plus helps to maintain the water quality.

The example below, is placed on a tributory of the River Ash, which is one of just 170 chalk streams in the UK, and of 200 in the world.

Gauge complete with integrated V-notch to measure flow through a NFM to prove its efficiency

To evidence that any investment in an NFM scheme is delivering results it is necessary to measure the flow through the watercourse for a period before the NFM is created and thereafter after it is constructed.

To measure the flow, it is often necessary to install a small temporary structure, as we have done here, to create a small dam and to include what is called a V-notch weir, which includes a gauge mounted in a stilling tube. The level of water flowing over this weir equates to flow rate and is measured and sent to an online monitoring platform via the cellular networks. During dry periods it is quite normal for the levels fall to near empty or empty and for there to be no flow. NFM is really all about slowing the flow during those big storm and heavy rainfall events, and often light showers will not create a noticeable flow, this is normal.

We appreciate the support of the public on this living science project, and should you have any questions or concerns please use our contact page, entitling you query with River Ash, NFM.

To find out more about NFM there are resources on the .Gov Website https://www.gov.uk/guidance/natural-flood-management-programme which can be reached using this link.