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Guidance

4. Monitoring and maintenance of nature-based solutions for water resources

Published 17 August 2026

Applies to England

© Crown copyright 2026

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This publication is available at https://www.gov.uk/government/publications/nature-based-solutions-for-water-resources-handbook/4-monitoring-and-maintenance-of-nature-based-solutions-for-water-resources

This guidance describes how to effectively maintain and monitor your nature-based solutions to achieve water resources benefits. It includes how to use monitoring to work out whether maintenance or adaptive management are needed.

Before you can monitor and maintain your nature-based solutions (NbS) for water resources, you will have:

1. Maintaining NbS projects

Once the construction phase of your NbS project has completed, the Construction (Design and Management) (CDM) Regulations require you to:

  • consider post-construction activities
  • develop an approach to the inspection and maintenance of the NbS which can be undertaken safely
  • ensure that the inspection and maintenance activities are done by appropriately trained individuals

You need to consider maintenance and adaptive management because failure of an NbS measure could have unintended consequences such as increasing flood risk downstream.

See guidance on how to minimise legal, financial and reputational risks associated with implementing NbS projects.

You should include maintenance and adaptive management in the organisation’s long-term funding plans to allow you to:

  • develop and implement a plan to assess the performance of NbS features
  • implement measures to adapt NbS features if they need to be repaired

Monitoring to inform project maintenance

You will need a robust monitoring plan to identify whether maintenance or adaptive management of NbS measures are needed.

Maintenance needs will vary from project to project, they might involve:

  • removing woody debris dams if they become dislodged
  • affixing NbS features (for example woody debris dams) to ensure they do not become dislodged in high flows
  • removing sediment from storage features to maintain their capacity
  • control and removal of encroaching scrub
  • replacing or removing tree guards

To reduce the need for long-term maintenance, your NbS project should be designed to work with natural processes.

Monitoring for the maintenance of NbS features can be as simple as:

  • site walkovers at regular intervals to inspect features
  • fixed point photography of NbS measures to understand their evolution over time

2. How to approach monitoring of NbS features

Importance of monitoring

Monitoring of NbS is important to:

  • demonstrate project success or failure
  • learn from mistakes
  • know when maintenance or adaptive management is needed
  • fill known research gaps
  • inform funders, partners and local stakeholders about project outcomes
  • determine to what extent project objectives have been met

You will need to plan and budget for monitoring and evaluation at the start of a project. If monitoring is not considered until after a project has been constructed, it may be too late to collect any useful data.

You can also use monitoring to help secure future funding and engage local communities.

Setting monitoring objectives

When developing a monitoring programme, you should begin by articulating the overall aim of the project to describe what you are trying to achieve. You should define clear objectives to help:

  • ensure that monitoring is cost-effective
  • ensure that monitoring is aligned to the project’s targets
  • identify what baseline data and resources are required for monitoring

The SMART approach

Monitoring should focus on demonstrating that project objectives have been achieved. Project objectives should be developed using the SMART approach. The SMART approach to objective setting helps to articulate what it is you plan to monitor and how you intend to go about it. It also helps define timescales for implementation and potential funding needed to complete the monitoring.

Following the SMART approach, adapted from the River Restoration Centre (RRC), your project objectives should be:

  • specific – target a specific area of improvement or answer a specific need
  • measurable – be quantifiable, or at least to allow measurable progress
  • attainable – be realistic and based on a review of evidence of success by others
  • realistic – be based on available resources (money, people, time) and existing constraints
  • time-bound – have a deadline or defined end

You should prioritise monitoring activities and target monitoring activities that help achieve your SMART monitoring objectives.

Monitoring is often hard to fund, so it is therefore useful to divide the activities into those that are deemed essential and those that are desirable. This could result in the development of alternative, lower-cost methods (for example fixed point photography) being sought to support the lower priority activities.

If you develop monitoring approaches without the SMART objectives, you risk wasting money and time by collecting data which does not help to answer a specific question.

3. Developing a monitoring plan

Developing a robust monitoring plan is important to help you understand whether maintenance or adaptive management of NbS measures will be needed.

Once your monitoring objectives are defined, you can develop a monitoring plan. This should follow a series of steps to help define whether a project has been a success and potentially unlock funding for future projects.

These steps (adapted from RRC) are:

  1. SMART project objective setting

  2. Detailed monitoring plan

  3. Effective monitoring plan

  4. Project with demonstratable success

  5. Results to help secure funding

  6. Future funding and capacity increased

Considerations when developing a monitoring plan

When developing your monitoring plan, you must begin by considering:

  1. How much data will be collected?
  2. How will the data be collected?
  3. How frequently will the data be collected?
  4. How will the data be recorded?
  5. Who will collect the data?

These questions will help you understand:

  • the quantity of data you will need to analyse
  • what format this data will be provided in
  • any data processing that might be needed

If multiple projects are being implemented throughout a catchment, they should collect and record data consistently to enable comparability between sites. For example, ensuring data is collected using the same metrics can save time later. This is because data from one site is immediately comparable with another without the need for additional processing.

When developing a monitoring plan, you should incorporate the need to review and assess how the NbS measures are performing, whether they are working as designed, and whether any adaptations are needed. This reflective process enables learning and will enable NbS features to be designed differently in the future if needed.

You must ensure that monitoring is undertaken over suitable timescales to understand the effectiveness of a measure. The amount of time needed to monitor an NbS measure will depend on how long it may take to become effective. Some NbS interventions will become effective almost immediately, whereas others will take longer.

You should also monitor NbS in times of high and low flows to understand how they perform in different conditions.

The RRC has a monitoring planner with further questions to help you define a robust approach to monitoring.

Spatial scale of monitoring

Monitoring needs to be proportionate to your project’s scale. For example, if one small localised NbS measure is being installed, the level of monitoring needed is less than for a wide range of NbS measures across a larger spatial scale.

For small-scale NbS projects, it may not be possible for you to fully understand its effect on groundwater. Monitoring should focus on understanding how the measure works.

For larger-scale NbS projects where a range of measures are installed across a larger spatial scale, you should develop an approach to monitoring that helps develop an understanding of the different measures’ impacts on groundwater.

Collecting a baseline

You should do baseline monitoring before NbS measures are constructed to help understand the environmental conditions of the site or catchment before construction.

Having a robust baseline allows you to understand the effectiveness of the NbS measures by comparing the study area before and after construction.

In an ideal situation, your catchment would have long-term baseline monitoring stations already in place, collecting data that enables you to detect environmental change following construction. This is rare. In most cases, pre-existing monitoring can be limited and may not be targeted at understanding the natural processes you are interested in.

If the existing baseline monitoring for a catchment is short term or patchy, this is likely to increase the uncertainty in the understanding of how effective the project has been and whether monitoring objectives have been met.

When developing the monitoring plan and associated SMART objectives, this should be informed by an understanding of:

  • what monitoring equipment may already be present in the catchment
  • what datasets already exist and are they available
  • the duration of any previous or ongoing monitoring
  • the quality of any existing data
  • which organisations within the catchment may hold or collect monitoring data
  • whether existing monitoring data is available and can be shared

Understanding what data already exists helps inform decisions related to the extent of monitoring that is needed. As a minimum, an adequate baseline dataset should capture a series of high and low flow events to understand how the catchment responds to both flood and drought conditions.

Limitations and extent of monitoring

You may find that quantifying and demonstrating the effectiveness of NbS measures is challenging. It can be hard to demonstrate that an NbS measure or a suite of measures affects their ability to regulate high and low flows because multiple natural pressures are exerted upon the natural environment.

It can also be difficult to understand whether the monitoring data shows a positive or negative response to the NbS measure (or measures). The data you have collected may show a change because of some unknown activity or pressure elsewhere in the catchment. This demonstrates the importance of carefully developing a monitoring plan that enables change to be detected.

When developing your monitoring plan, you should think about the extent of monitoring that might be possible based on project timescales and budget. The following list summarises different scales of approach to monitoring. Water Resources East’s best practice guidance contains helpful classifications of monitoring approaches into ‘gold standard’, ‘standard’ and ‘basic’ categories.

Detailed monitoring approaches

Detailed approaches to monitoring are clearly the gold standard. These are usually led by academic institutions and support a long-term assessment of effectiveness compared against a baseline.

Detailed monitoring approaches:

  • typically follow a Before, After, Control and Impact (BACI) approach to monitoring
  • include a long period of baseline data collection, either set up specifically for the project, or drawing on existing baseline data collection
  • may include a control site which can be compared against the site where NbS is being implemented to understand the effect of measures
  • include a representative monitoring design approach which helps understand the effect of the NbS measures rather than collecting data about other catchment processes

Lighter touch monitoring approaches

Lighter touch approaches to monitoring alongside collecting monitoring data to inform modelling are more frequently used. Together they help you understand the effect of your interventions on water cycle processes or collect data that enables you to model the impacts of your interventions.

Lighter touch monitoring approaches:

  • are focused locally, typically at a site level
  • typically lack a baseline or control site
  • sometimes, the monitoring approach and associated network are installed after construction
  • focus on understanding the effect of measure(s) on the water cycle
  • aim to understand or describe how the measure works during high and low flows and affects natural processes

Monitoring for modelling

Monitoring for modelling approaches:

  • collect hydrological data (for example flow, soil moisture, hydraulic conductivity)
  • collect field data to inform, parameterise, calibrate and validate a model
  • use the model to assess the effect of NbS measures under different flow regimes

Resources to help plan monitoring

There are some existing resources available to help project managers plan their monitoring, which include:

4. Monitoring techniques

Once your monitoring plan is in place, your next step is to implement it and start collecting the necessary data.

You should select monitoring techniques that help to understand how the NbS measures installed affect the flow of water across and through the landscape, such as:

  • evaporation and transpiration
  • interception
  • infiltration
  • hydraulic roughness
  • flow (discharge)
  • storage

Table 1 shows an overview of different approaches to monitoring, including the processes they collect data on and the instruments used.

For the evidence base on these different approaches to monitoring, see Appendix 1: NbS for water resources case studies.

Table 1: Summary of potential monitoring techniques including costs (indicative only, accurate for 2026)

Monitoring approach Processes being monitored Instrumentation used and approximate costs
Dipwells Infiltration and baseflow Dipwells and piezometers – £10 (home-made with drainpipe) to £150
Emerging technology Can be used to monitor a wide range of natural processes Autonomous sensors – range of costs for different automated loggers (Low-cost electronic sensors for environmental research: Pitfalls and opportunities)
Flow/discharge assessment Water flow or discharge V notch weirs at the intake and outtake of the site – £350 (plus water level monitoring equipment)

Pre-fabricated flumes
Groundwater boreholes Groundwater levels, infiltration and recharge Existing boreholes – staff time only

New boreholes – may be several thousand pounds (depending on depth)
Soil infiltration tests Infiltration Drainpipe and stopwatch and Soakaway Test – £10
Mapping site details Location, scale and description of NbS measures N/A – staff time only
Photography and drone flyovers Water interception and storage and flow routes Fixed point photo posts – £10

Drones – £500 to £10,000

Timelapse photography – £400 to £2,500 (ALERT data is freely available)
Soil health and biology assessments Infiltration and flow or runoff pathways Soil compaction surveys – staff time

Soil organic matter assessments – staff time to collect samples, £100 per sample for lab analysis

Soil moisture probes – £300 to £1,500

Double-ring infiltrometers – £200 to £2,000

Automatic data logging weighing lysimeter – £3,000 to 230,000

Field-scale weighing lysimeter – £250

Lab analysis of samples – £100 per sample
Surface roughness assessment Flow or runoff pathways N/A (refer to lookup values in the literature based on empirical testing) – staff time only
Water levels and storage volumes Water levels (stage), storage volumes Stilling wells – £25

Stage boards – £60

Water level logger – £350

Barometric logger – £300
Wet canopy evapotranspiration Evaporation, transpiration, infiltration Stemflow collar and tank – £50 (Pipe and Water butt)

Throughfall collectors – £50

Relative humidity sensors – £150 to £1,000
Geophysical surveys Groundwater levels, groundwater flow pathways, subsurface hydrogeological properties Ground penetrating radar (GPR), electromagnetic surveys, microgravity surveys, electrical resistivity tomography (ERT), seismic surveying (for example, Tromino)

Highly variable cost, depending on the techniques used and the size, accessibility and nature of the site

Dipwells

Dipwells are slotted tubes installed to a depth greater than the lowest known or anticipated water table. They can be used to monitor the elevation of the water table at fixed points within a site, to understand groundwater levels, infiltration and baseflow.

Dip wells or piezometers are available commercially. Prices vary from £45 to £150 each. Dip wells can be constructed from wastewater pipe, geotextile fabric and duct tape for under £10. 

References used:

Emerging technology

Autonomous sensors are an emerging technology which uses Artificial Intelligence and Machine Learning to undertake real-time monitoring. This approach involves placing sensors throughout a catchment to capture data and use this real-time information alongside satellite imagery to provide an overview of a catchment’s health. It can be used to monitor a range of variables and natural processes.

This is an emerging area which, as it develops, could be applied on NbS schemes to help understand their performance and effectiveness.

References used:

Flow or discharge assessment

To understand the effect of NbS interventions, you first need to develop a baseline understanding of flow or discharge for a range of flow conditions across the catchment. You can do this by undertaking a desk-based assessment using:

  • model results
  • past catchment studies
  • existing gauging stations

You can instrument your catchment with flow or discharge data collection equipment in locations where interventions are planned. This allows you to collect baseline data before construction to compare the effects of NbS measures on flows before and after interventions are installed.

You could install V notch weirs (or prefabricated flumes) at the location where the watercourse enters and leaves the site. If you collect data at both weirs, you can understand water flow throughout the site. You can also use this data to infer how much water is being lost through infiltration or storage.

Following construction, you should retain the monitoring equipment as long as feasible or affordable. This is so you can create an adequate monitoring dataset to help understand the effectiveness of the NbS measures on flow or discharge.

You should undertake a desk-based review of the monitoring data. This is to provide a statistically robust analysis describing changes to river flow following the construction of NbS interventions (likely to involve hydrograph analysis).

Scottish National Heritage has produced a guide which describes how to manage and monitor surface water levels and flows on fen sites.

References used:

Groundwater boreholes

You can monitor changes in groundwater levels where NbS interventions are located close to existing groundwater level monitoring boreholes with suitable long-term records. The Environment Agency has produced a guide which describes how to monitor groundwater levels and flows on wetland sites. 

You need to do a statistically robust analysis describing changes to groundwater level records:

  • before and after constructing NbS interventions (likely to involve hydrograph analysis)
  • in tandem with the development of a strong conceptual understanding of the system
  • on long-term groundwater level records

This is needed to help you work out if groundwater levels and recharge have been influenced by the installation of NbS measures and additional storage within the catchment. It is likely to involve a lag time assessment and the analysis and interpretation of groundwater levels during periods before and after NbS installation.

References used:

Soil infiltration tests

You can use the BRE365 infiltration test approach to understand the rate of infiltration of water into the subsurface. You can use this approach to inform the design of soakaways but can also be used to assess potential infiltration rates.

You can do this easily by digging a hole, installing a short section of drainpipe, filling it with water and then timing the rate at which the water is absorbed into the soil. Alternatively you can use a purpose-designed item of equipment such as a Guelph permeameter.

References used:

Mapping site details

On any project which is being monitored, it is important to capture enough information on a map to describe the site, its location and the measures being installed.

This should include but not be limited to:

  • location of the site (or sites) including a red line boundary and grid references
  • description of the type (or types) of NbS intervention installed or planted
  • extent or scale of NbS intervention (or installations) installed or planted – using the length of river affected, the area of land affected or the amount of water storage provided

Photography and drone flyovers

Useful tools to help you understand how NbS measures intercept or store water, or both, include:

  • fixed point photography
  • timelapse cameras
  • drone footage

You can set up fixed point photography posts in advance so that all photos taken at the sites are taken from the same vantage point. This allows you to compare the site’s evolution over time.

You should undertake fixed point photography during times of high flow to illustrate how the measures are working (for example, intercepting flow and storing water).

The RRC has published a factsheet for fixed point photography.

Timelapse cameras can be inexpensive and easy to set up and capture data with minimal intervention, except to retrieve memory cards to download data.

You can use drone footage to capture and map water flow routes and flood outlines. You can set drone flights to cover the same routes to collect repeatable and comparable datasets. This will allow you to capture different flow events repeatably over time.

Soil health assessment

To understand how NbS measures which improve soil management affect water infiltration and storage, you need to collect baseline data to understand how the soil’s structure has changed over time. From this, you can infer a change in infiltration and storage.

You can then use improvements or changes to the soil to model the effects of land use change to understand its affect on groundwater, such as:

  • photos and observations during and after rain at the field scale, showing off-site impacts linked to accelerated runoff
  • organic matter content as an indicator of soil health and water holding capacity, including worm counts
  • soil moisture data from probes before and after installation of NbS interventions
  • simple soil pit examination – three per field in representative areas of the site (not in the margins or heavily trafficked areas)
  • soil compaction assessment before and after land use/land management change using soil pits and standard National Soil Research Institute (NSRI) methodology
  • soil infiltration measures using double-ring infiltrometers, lysimeters or runoff plots
  • runoff plots and lysimeters should provide either runoff in volume and or a soil potential rating for that field

The AHDB has published guidance on assessing soil health using an integrated approach.

Surface roughness assessments

The hydraulic roughness of an area of land will change due to the installation of NbS interventions. Understanding any changes in manning’s ‘n’ roughness coefficients will allow you to model your NbS interventions to understand their effect on the flow, storage and infiltration of water across the landscape.

To monitor changes in roughness, you will need to understand the roughness of the site pre-construction. This is so that the intervention can be modelled before and after construction using different roughness coefficients.

Water levels and storage volumes

Installing a stage board within an NbS feature can help you to establish water depths and flow paths. You can correlate these water level or stage measurements with measurements of rainfall intensity and river stage to compare the filling of the storage feature with peak discharge in the river. This will help you understand flood levels and storage volumes during periods of high and low flow.

Fixed point photography and drone flyovers are useful for capturing flood outlines, from which we can infer flood storage capacity of NbS features.

The reference used is Chapter 6. Research Gaps and Monitoring. In: Working with Natural Processes Evidence Directory (Burgess-Gamble and others, 2017).

Wet canopy evaporation

Wet canopy evaporation involves monitoring tree canopies to understand the effect on evaporation, transpiration and infiltration using:

  • stemflow collar and tank
  • throughfall collectors
  • relative humidity sensors

The Natural Environment Research Council (NERC) project Quantifying the likely magnitude of nature-based flood mitigation effects across large catchments (QNFM) developed a methodology for monitoring the impacts of woodland planting on evaporation. They created a monitoring approach which collects data on gross rainfall (the rainfall that is received by the canopy) and net rainfall (the rainfall that reaches the ground). The difference between gross and net rainfall enables wet canopy evaporation to be calculated.

References used:

Geophysical surveys

Geophysical surveys offer non-invasive methods to monitor water resources by analysing subsurface properties.

You can use geophysical surveys to map the water table and monitor changes in groundwater levels over time. This is particularly useful in areas where groundwater is a critical water resource or where groundwater flooding is a concern. 

Common techniques include:

  • electrical resistivity tomography (ERT) – measures resistance to electrical current to identify water ingress
  • ground penetrating radar (GPR) – using radar waves to detect subsurface features like voids
  • seismic surveys (for example Tromino) – which analyse wave propagation to map subsurface layers

You can also use electromagnetic methods, including Ground Conductivity, to assess moisture content. Microgravity surveys are also used. These will help you in mapping groundwater, detecting leaks, and understanding hydrological processes.

References used:

5. Monitoring case studies

This section provides some examples of different approaches to monitoring.

Table 2 provides an overview of different approaches to monitoring used on the different case study sites and it summarises which processes they collect data on and what instrumentation is used.

Table 2: Summary of potential monitoring techniques

Project name Processes being monitored Instrumentation used
Bishopdale NFM project (Yorkshire) Infiltration, soil moisture Soil moisture monitoring unit
Culm grasslands project (Devon) Infiltration Dipwell, rain gauge, soil samples (assessed for moisture content and bulk density)
Holnicote Estate (Somerset) Water flow, water storage, infiltration, geomorphological evolution of the site River sensors, drones, sediment transport monitoring, ecological surveys
Blairfindy catchment (Scottish Highlands) Infiltration, groundwater recharge, soil water content Weather stations, stage data recorder, End-member Mixing Analysis
Mires on the Moors (Devon and Somerset) Changes to the water table, water quality, biodiversity Water level monitoring, water quality monitoring, rain gauge, dipwells
Stroud Valleys (Gloucestershire) Hydrograph attenuation, groundwater recharge Doppler flow meter, soil moisture probes, piezometers, stilling wells

Bishopdale NFM project (Yorkshire)

The Bishopdale NFM project focused on reducing flood peak and the time it takes for water to be transferred throughout the catchment by using natural flood management techniques. It included tree planting, storage of water in offline ponds and scrapes and improvements to soil health. Yorkshire Dales Rivers Trust implemented a range of monitoring approaches. Dales Land Net implemented the soil monitoring described below.

Dales Land Net has developed a soil moisture monitoring unit that transmits real-time data about how wet the soil is in a specific location, measuring the soil from the surface down to a depth of 50cm. These readings are transmitted to the server using Internet of Things (IoT) technology that allows the unit to run for several years on only 3 AA batteries and a small solar panel. The sensor in the soil is divided into 4 zones which may each have differing levels of moisture due to the soil layer composition. The sensor also provides temperature readings from 6 depths.

Culm Grasslands project (Devon)

The Culm Grassland Natural Flood Management project was led by Devon Wildlife Trust with the Environment Agency, Exeter University and other partners.

This rare habitat, a type of purple moor-grass and rush pasture particular to north Devon, is important for wildlife, but it also has real potential to hold water, filter pollution and retain carbon.

This project restored 468ha of this habitat and undertook extensive monitoring to understand the impacts of the restoration.

The aim of this objective was to understand soil conditions and water table response to rainfall in Culm grassland compared to improved grassland.

The monitoring undertaken at each field plot of 30m by 50m included:

  • 5 soil samples were taken to 0.15m depth, making a total of 45 samples. Each sample was divided into the organic layer of soil (O horizon) and the A horizon. Each sample was then processed in a laboratory to assess soil moisture and compaction
  • at each field plot, five dipwells were installed to 0.5m depth, with a data logger recording water table depth at 15-minute intervals
  • a rain gauge was also installed at each site for accurate rainfall measurements also at 15-minute intervals

The results of fieldwork indicate that Culm grassland holds more water than improved grassland and has the ability to release the water more slowly into the catchment.

Holnicote Estate (Somerset)

The National Trust ran a 3-year project on their Holnicote Estate in Somerset to reconnect a section of a river to its floodplain to create a new and instantly different waterscape using the innovative ‘Stage 0’ river restoration technique. The project was monitored to understand its impacts on water resources, water quality, habitat and geomorphology.

The monitoring found that ground water levels rose dramatically across the site, in some places by over 1m. This allowed the site to act as a large sponge or filter in the river catchment, helping to store winter flood water, reducing flood risk downstream and releasing cleaner water more slowly in the drier months to help alleviate drought conditions.

Monitoring has revealed a water table increase of up to 1m across the site, resulting in a big increase in water storage and helping to improve conditions for migratory fish and reduce the impacts of agricultural pollution.

Blairfindy catchment (Scottish Highlands)

For this study in Scotland, runoff attenuation features (RAFs) (mainly leaky barriers) were installed by a distillery to intercept flow pathways and create temporary storage. The purpose of this was to increase infiltration and groundwater recharge to provide resilience to drought conditions. The site was monitored to understand the effectiveness of measures.

Monitoring data was combined with modelling and showed that RAFs:

  • increase recharge
  • increase groundwater contribution to streamflow and low flows
  • reduce high and mean flows

The results suggested that RAFs could help mitigate the impacts of low flows through periods of drought. It was found that distributing multiple features across the site was more effective than having one large RAF.

Mires on the Moor (Devon and Somerset)

For the Mires on the Moors project, South West Water’s Upstream Thinking Programme restored 2480ha of peatland across Exmoor and Dartmoor. Monitoring was important to this investment programme to understand the impacts of restoration measures on water resources, water quality and biodiversity.

At Exmoor a network of dip wells was installed in proximity to restored drainage ditches to understand water table depth below the surface. On Dartmoor the monitoring approach measured spatial patterns of water table depth and runoff from a single gully. Water tables were measured as the depth of water below the ground surface using a network of dipwells.

In relation to water level monitoring the research found that:

  • in the driest areas of the shallow peats, water tables rose by as much as 4cm after restoration
  • overall, water tables were seen to remain statistically similar post-restoration

In deeper peats, restoration increased the permanent deep water storage in the soil by 7.3cm and increased average water tables by 2.45cm.

Stroud Valleys (Gloucestershire)

The Stroud Valleys NFM Project, led by Stroud District Council, involved the implementation of measures throughout the catchment of the River Frome in Gloucestershire. Monitoring of the scheme was undertaken in partnership with the University of Gloucestershire, the Wildfowl and Wetlands Trust, Gloucestershire Wildlife Trust and the Environment Agency to understand the impacts of the measures, particularly in terms of reducing flood risk within the catchment and increasing recharge to groundwater.

Monitoring of discharge upstream and downstream of intervention sites demonstrated the effects on flood hydrographs, revealing that peak flows were significantly attenuated following the installation of measures.

A network of soil moisture probes and piezometers intersecting the water table were implemented in the vicinity of newly installed earthen retention bunds. Data from these instruments, in combination with meteorological data, were used to quantify groundwater recharge rates. In doing so, the impacts of the measures in terms of increasing infiltration could be assessed.

6. Evaluating your monitoring data

As monitoring starts to yield results, you will need to analyse the data and interpret it to understand and communicate the study’s findings. You will need to discuss the results with a range of disciplines to get an agreed understanding.

Artificial Intelligence and Machine Learning approaches can be used to interpret and evaluate monitoring data. These novel approaches have been used in analysing and identifying patterns in large monitoring datasets. It is therefore potentially applicable in the field of NbS for water resources.

You should explain what the data shows, including all caveats and limitations. You must be scientifically objective about the study’s findings, as this enables project-level learning and improved scientific understanding. The results need to be understood by a wide range of stakeholders, so you should consider how to describe the results using plain language.

The results of monitoring will help you to determine whether NbS measures need either maintenance to fix a problem or adaptive management to adapt the design to take account of unexpected changes needed.

7. Project decommissioning

The final stage in your construction project may involve a decommissioning phase, where you take steps to hand over responsibility for assets to a landowner.

This stage can involve retrieving your monitoring equipment that is no longer needed or filling in boreholes that were constructed during an earlier phase of work.

You will likely need to engage with the landowner to design and agree a long-term plan for any necessary maintenance works.

You should allow for the costs of the decommissioning phase while planning your NbS for water resources project.

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8. Contact the Environment Agency

If you have questions about any aspects of this guidance, contact the Environment Agency.

General enquiries

National Customer Contact Centre
PO Box 544
Rotherham
S60 1BY

Email enquiries@environment-agency.gov.uk

Telephone 03708 506 506

Telephone from outside the UK (Monday to Friday, 8am to 6pm GMT) +44 (0) 114 282 5312

Monday to Friday, 8am to 6pm.

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