Monitoring underpins investment in Riverlands NFM Project

OTT Hydromet is working with the National Trust to implement a monitoring programme to provide robust data on the efficacy of Natural Flood Management (NFM) projects in the UK’s Lake District. Working with partners, the National Trust has established the Cumbria Riverlands Project, which stretches from Keswick in the north to Kendal in the south. It encompasses the rivers themselves, the land which drains into them, and a rich array of wildlife and plants. The project is funded by a grant from the Environment Agency’s Natural Flood Management Programme.

Two of the key locations in the project are Windermere, and further north in Coledale. Given the scale of the proposed works, the National Trust has taken steps to ensure that decisions are data-driven. For example, rain gauges and a network of surface and groundwater monitors have been installed by the instrumentation company OTT HydroMet, to establish baseline conditions, and to later measure the effects of the NFM initiatives.

Background

In December 2015 Storm Desmond inflicted major disruption, flooding and damage to the northwest of England. This included the flooding of 40 properties in Windermere following intense rainfall and the rapid rise of two becks (small streams) that pass from higher ground through the town and into Lake Windermere.
Flash flooding was also experienced in areas surrounding Coledale beck, downstream of the Force Crag Minewater Treatment Scheme, where the beck runs through the village of Braithwaite to the west of Keswick.

Natural Flood Management (NFM)

Natural Flood Management is generally regarded as a more sustainable alternative to traditional methods involving engineered flood defence infrastructure. A core feature of NFM is that it addresses flood risk on a catchment scale so that upstream initiatives do not create negative impacts further downstream. This catchment-based approach requires flood management solutions that employ techniques which work with natural hydrological and morphological processes, rather than artificial structures that generally increase flowrates. NFM techniques therefore include the restoration, enhancement and alteration of natural features such as flood plains, which can help to lower peak flow and decrease flood risk.

Cumbria Riverlands Project

A strategic plan has been developed to implement a range of NFM measures at both Windermere and Coledale. Working with local landowners and partners such as the Environment Agency, Natural England, the West Cumbrian Rivers Trust and others, the National Trust has submitted ambitious planning proposals for the catchments around Coledale and Windermere. Coledale is owned and managed by the National Trust, and the fells above Windermere include two farms, High Lickbarrow Farm and Common Farm, both of which are managed by the National Trust.
“Our plan is to create over 30,000 m3 of water storage,” explains Project Officer Hannah Haydock. “This will be achieved through the construction of 16 ponds and other work to re-establish wetlands, and deliver a number of important benefits. For example, in addition to the reduction of flood risk, wetlands improve carbon sequestration, protect water quality and enhance biodiversity.”

Windermere and Coledale have both suffered historic flooding and were particularly impacted by Storm Desmond in 2015. Hannah says “Our objective with NFM is therefore to ‘slow-the-flow’ by restoring wetlands, planting trees and by removing or blocking the culverts and drains that previously accelerated the removal of water.”
Climate change is increasing the frequency and intensity of extreme weather, so initiatives such as the Cumbria Riverlands Project are designed to improve climate resilience.

Water monitoring

In order to be able to define the scope of works for the project, it was first necessary to develop a model including the hydrology and geomorphology of the catchments. Such models rely heavily on real-world data on rainfall, water level and flow. Networks of raingauges and water level monitors were therefore installed toward the end of 2024. These monitors have two main purposes. First, by installing them several months before the proposed start of construction, it becomes possible to establish baseline data. Second, once the NFM measures have been established, the monitors will enable the project team to measure how successful they have been at slowing the flow.
The water monitoring equipment included two OTT logging raingauges to supplement two existing Environment Agency raingauges. In addition, OTT HydroMet engineers installed 9 ecoLog water level monitors above Windermere, and 6 ecoLogs in Coledale.
The OTT ecoLog 1000 is a complete all-in-one water level monitor, designed for long-term deployment in challenging environments. Operating on very low power, with replaceable battery life up to 10 years, the ecoLog 1000 measures water level with a robust, vented ceramic sensor in a stainless-steel housing with a kevlar-reinforced cable. OTT ecoLogs are generally installed in boreholes for groundwater monitoring, and in lockable stilling wells for surface water applications.
The ecoLogs take measurements every 15 minutes and store the data internally, and with wireless Bluetooth communications, National Trust Rangers are able to visit the monitors on a monthly basis to collect the data rather than transmit data with the device’s integrated modem. “We could have chosen to use the ecoLogs’ built-in telemetry,” Hannah explains, “but by saving money with manual data collection we were able to purchase more monitors, and our Rangers are on-site regularly in any case.”
The National Trust also purchased an OTT MF Pro portable water flow meter, and OTT engineers provided 6 National Trust Rangers with training on how to use the MF Pro to measure flow rates in small streams. Consequently, it was possible to automatically translate the ecoLog level measurements into flow, so that both water level and flow could be recorded.
In addition to water level monitoring, the project will also include ecological surveys to assess the effects on biodiversity, and volunteers will conduct citizen science water quality spot-checks every month.

Looking forward

With widespread local support, Hannah is confident that the scheme of works will receive appropriate planning permission. “By the time NFM works are complete, we will probably have collected over a year of data,” she says. “So far, the monitors have worked extremely well, and we have 100% data integrity, so we are excited to learn what our initiatives will ultimately deliver.”
In addition to the environmental, sustainability and climate resilience effects of the project, Hannah says: “One of the major objectives will be to demonstrate how nature restoration and environmental protection can work hand in hand with commercially viable farms. So, we plan to take the lessons learned from the Cumbria Riverlands Project and apply them elsewhere.”

OTT HydroMet manufactures products that enable water professionals to monitor the planet’s most precious resource. Through the delivery of accurate reliable data, OTT HydroMet’s instruments and services provide essential tools to help protect the environment.
From precipitation through surface and ground water to marine monitoring applications, OTT’s measurement and communication technologies provide a complete picture of the water cycle. OTT and Hydrolab have been longstanding members of OTT HydroMet. Adcon Telemetry was acquired in 2011; Sutron and Lufft joined the group in 2015; Kipp & Zonen joined in 2017, and Aquatic Informatics joined the now Veralto Water Quality platform in 2020, which means that the company is able to offer the best sensors and data handling technology and software for every application.
Completely focused on hydro-meteorology and water quality, OTT HydroMet’s product brand OTT has been market leaders for over 150 years and coupled with modern communications technology provide remote access to continuous monitoring data.  Further information is also available at www.otthydromet.com 

Dr Liam Goodes has a MSci degree in Oceanography from the University of Southampton, and a PhD in Engineering (also Southampton). Following 4 years in research, Liam has worked in technical business development roles within leading global businesses for over 9 years. At OTT HydroMet Liam is responsible for helping UK customers to develop advanced monitoring systems to protect and enhance assets from water and weather-related risks.