Research and analysis

6. Navigation - drought risks, impacts and actions: Drought prospects for spring 2026

Published 14 November 2025

Applies to England

This section looks at navigation owned and managed by the Environment Agency and by the Canal & River Trust.  

There are concerns regarding the prospect of a dry winter, especially where the navigation network is:  

• fed by rivers 

• supported by groundwater or reservoir sources (some of which reached historic lows this year) 

• overhung by trees that have fallen at higher rates in the drier conditions 

• on tidal rivers where reduced freshwater flows have resulted in saline intrusions further upstream than typical 

6.1 Summary of Environment Agency navigation impacts 

The Environment Agency owns and manages a network of 630 miles of navigation across several inland waterways, mainly: 

• the non-tidal River Thames  

• the Medway navigation  

• the Anglian waterways (Rivers Ancholme, Great Ouse, Nene, Stour, Welland, Glen, and the Black Sluice Navigation)  

If there is below average rainfall over the autumn and winter, we would expect to see an increase in navigation restrictions and closures across our navigation networks. This may impact the start of the peak boating season from spring 2026.  

We will review any planned winter maintenance work on our navigational assets to alleviate pressures on the networks if low flows continue. Even with a 100% LTA rainfall scenario this winter, some navigation restrictions may remain in force until next year, particularly where networks are supported by reservoirs at very low levels. 

6.2 Summary of Canal & River Trust impacts 

The Canal & River Trust looks after a network of 2000 miles of canals and navigable rivers. The Trust supplies its canals with water from its 72 reservoirs (51%) and abstraction from surface water (30%) and groundwater (10%).  

The Canal & River Trust does not envisage any issues or challenges from dry weather in terms of impacts on water supply for maintaining navigation over the winter period. Some reservoir maintenance is planned over the winter that requires levels to be held down, reducing water availability and full refill of those reservoirs. This is more likely to result in issues with water supply and canal levels in 2026 for the start of the boating season than through the autumn and winter months.  

The Canal & River Trust notes that if a network is 25% closed there is a very high risk of environmental damage, houseboat evacuations and structural damage to the canal network. 

6.3 100% long-term average rainfall scenario 

Environment Agency navigation 

In this scenario there may be sufficient recovery in river levels to mean a normal beginning of the 2026 peak boating season (from Easter 2026). We would then have higher confidence in our management of navigation levels into spring 2026.  

Canal & River Trust 

In this rainfall scenario, the Canal & River Trust expects the impacts from drought to continue in some areas (figure 13):  

• 2 canals (Oxford and Grand Union Canal and South Oxford Canal) are likely to have 15% to 25% of the network closed  

• 2 canals (Grand Union Tring and Grand Union South) are likely to have 5% to 15% of the network closed

Figure 13: Canal & River Trust drought risk for 2026 under a 100% LTA rainfall scenario

6.4 80% long-term average rainfall scenario 

Environment Agency navigation 

In this rainfall scenario, we expect our network to be more at risk of drought and low levels when they are fed by river, groundwater and reservoirs. The following navigations may be affected:  

• Thames  

• Great Ouse  

• Nene 

• Stour  

We also expect impacts where our network is connected to Canal & River Trust navigations that have experienced more severe drought impacts over this summer. In 2025, significant closures on the Canal & River Trust network left boaters ‘stranded’ on our waterways, where we have shared licence agreements. We had to waive fees for visitor use beyond the usual limits as boaters were unable to leave our waterways. We expect these conditions to continue in this scenario (see figure 14). 

We expect many impacts from spring 2026 in this scenario, including: 

• an increase in navigation restrictions, such as less frequent lock operation and mandatory closures of locks  

• an increase in silt deposition and an increased risk to boats grounding and requiring rescue in shallower areas  

• some permanent moorings may become unusable due to reduced water levels 

• an increase in weed growth, bank collapse and algal blooms  

• an increased number of trees drying out, and falling into or obstructing watercourses 

• some delays to planned maintenance and capital works 

Canal & River Trust 

In this scenario, the Canal & River Trust expects an increase in the impacts from the below average rainfall:  

• 2 canals (Oxford and Grand Union Canal and South Oxford Canal) are likely to be over 25% closed 

• 2 canals (Grand Union Tring and Grand Union South) are likely to have 15% to 25% of the network closed 

• 4 further canals are likely to have 5% to 15% of the network closed

Figure 14: Canal & River Trust drought risk for 2026 under an 80% LTA rainfall scenario

6.5 60% long-term average rainfall scenario 

We would expect to see significant navigation restrictions and closures in this scenario. Major annual public events on and around the waterways may also be affected as well as a very high risk to public safety.  

Environment Agency navigation 

In this scenario, we would expect to see significant navigation restrictions and closures and may need to review or postpone winter drawdown and major capital works to reduce pressure on the network. Major annual public events on and around the waterways may be affected, and abstractions reliant on impoundment by navigation assets may face restrictions.  

Any more severe impacts experienced by neighbouring Navigation Authorities may have further impacts on our navigation assets and systems for water level management. Neighbouring Navigation Authorities include the Canal & River Trust, the Port of London Authority and council-run reaches of watercourses. 

A further risk in 2025 has been from the higher levels of anti-social behaviour in and around our assets in the hottest summer on record. Members of the public have intentionally opened our locks, draining impoundments at a faster rate than through normal use.  

Waterways attract the public for various recreational activities. Lower water levels in a 60% LTA rainfall scenario presents a heightened risk of submerged obstacles damaging vessels or injuring people on and in the water. Along with riparian landowners, we are considering how we can manage this heightened water safety risk. 

Canal & River Trust 

In this scenario, the Canal & River Trust expects a significant number of its hydrological units to be either closed or partially closed (figure 15) including: 

• the Oxford and Grand Union canal is likely to be fully closed 

• 4 canals (South Oxford Canal, Grand Union Tring, Grand Union South and Huddersfield Narrow canal) are likely to be over 25% closed 

• the Birmingham Canals Navigation is likely to have 15% to 25% of the network closed  

• 13 canals are likely to have 5% to 15% of the network closed

Figure 15: Canal & River Trust drought risk under 60% LTA rainfall

6.6 Actions to reduce the impacts of a dry winter and drought in spring 2026 on navigation 

Environment Agency navigation 

If we have below average rainfall over the autumn and winter, we expect to see an increase in navigation restrictions and closures across our navigation networks. This requires reductions in the frequency of lock operations and potentially delaying or stranding boaters.  

We would need to take action to: 

• isolate lock sites to preserve water levels (such as by not permitting public operation)  

• increase channel inspections and maintenance of banks, fallen vegetation and weed growth 

• implement actions to support ‘stranded’ visitors from other Navigation Authority areas and ensuring continued compliance with our own statutory duties for vessels to be registered and compliant with Boat Safety Scheme standards 

• review planned winter maintenance work on navigational assets to alleviate pressures on the networks during time of low flows  

Canal & River Trust  

The Canal & River Trust will follow its drought plan and intensify its monitoring and projections around late December or early January if there are reservoir groups still showing a lack of recovery (as was the case in the 2011 to 2012 drought).  

If the situation persists into 2026, the Canal & River Trust will begin contingency planning for the 2026 boating season. The Canal & River Trust will develop further drought communications plans for its boating customers. Its existing plans focus on communicating the impacts to boating customers and related businesses during the main boating season where these impacts are typically most significant.