Are our reservoirs recovering after Rochdale's exceptionally dry summer?

After weeks of heat, dry ground and remarkably little rainfall, attention is turning to the North West's reservoirs — and whether the return of more changeable weather has begun to undo the damage.

The short answer is: not yet, based on the latest reservoir figures Rochdale Daily has been able to verify — although the overall regional position remains considerably better than it was this time last year.

United Utilities publishes figures covering the major reservoir systems supplying the North West. For the week ending 19 July, total regional reservoir storage stood at 70.6%. That was down 4.1 percentage points in just one week and slightly below the 72.7% average for that point in the year.

Of particular interest to Rochdale are United Utilities' Pennine sources. These were at 64.3% capacity by 19 July, having fallen four percentage points in a week. The normal level for that point in the year is 66.6%.

There is some reassuring context. At the same point last year, the Pennine sources were at just 42.2%. That means that despite this summer's prolonged dry weather, Pennine storage remained more than 20 percentage points higher than during the equivalent week of 2025.

Haweswater and Thirlmere — enormously important components of the North West's water-supply system — stood at a combined 67%. That represented a fall of 4.7 percentage points in a week, although it remained above the 64% seasonal average and above last year's 60.3%. At Thirlmere itself, the water surface was recorded at 4.01 metres below top water level.

Across the major reservoir groups, regional storage was 70.6%, Pennine sources 64.3%, Haweswater and Thirlmere 67%, Dee and Vyrnwy 76.5%, and Carlisle 66.8%. Every major group recorded a weekly decline, with Carlisle falling nine percentage points in a week.

So will a few rainy days refill them? Unfortunately, reservoirs do not work quite that quickly. Rain falling onto Rochdale does not translate immediately into an equivalent rise in reservoir storage. After a prolonged dry spell, rainfall must interact with dry soils, vegetation, rivers and the wider catchment before significant quantities reach reservoirs, while homes and businesses continue using water every day.

This is why several genuinely wet periods — rather than a couple of showers — can be required before reservoir levels show a meaningful and sustained recovery. The North West also operates as an interconnected water-supply system, meaning Rochdale's water security cannot be judged simply by looking at the nearest reservoir and seeing how full it appears.

The dry conditions have accompanied an exceptionally hot start to summer. By the middle of July, England and Wales had each received only around 34% of their normal rainfall for the entire summer season, despite being halfway through meteorological summer. Some locations had recorded no measurable July rainfall at all by that point.

Temperatures have also been extraordinary. By 15 July, the UK had already experienced more days above 30C during 2026 than occurred during the whole of the famously hot summer of 1976.

The Environment Agency has consequently been closely monitoring water resources across England, while United Utilities was under enhanced monitoring and operations for its Haweswater and Carlisle water-resource zones during July. Wildfires across Greater Manchester, Cheshire and Derbyshire created additional pressure, with significant quantities of water also required for firefighting.

The figures require perspective. Storage has fallen substantially and the Pennine system was below its seasonal average in the latest verified snapshot, but this is not the same situation as last summer. Pennine sources being at 64.3% compared with 42.2% at the same point in 2025 gives the region considerably more resilience. Haweswater and Thirlmere were also above both their seasonal average and last year's level.

The key question now is what happens during August. Several weeks of regular rainfall could begin rebuilding water resources. A return to prolonged heat and dry weather, however, would place further pressure on reservoir stocks at precisely the time when summer water demand remains high.

For Rochdale residents looking at exposed reservoir banks and wondering whether recent rain means the problem is over, the answer is more complicated: the North West entered the dry spell with a healthier reserve than last year, but reservoir stocks have been falling quickly and recovery requires sustained rainfall rather than the occasional wet day.

Rochdale Daily will continue tracking reservoir levels as new figures are published.