May is the right time to look honestly at how water reaches your site, where it does not reach, and what you will do if June brings three dry weeks instead of one. The audit takes an hour or two. The decision it prevents can take days and cost far more.

Know what water you actually have

Start with sources. If you rely on a mains connection, check your meter, your pressure under flow, and whether you face any abstraction restrictions. Hosepipe bans have targeted amenity users in previous dry summers, so sites that depend entirely on the mains carry real vulnerability. If you have a borehole, a storage tank or access to a pond or watercourse, find out what volume each can reliably supply across a prolonged dry period, not what it delivers in spring when the water table is full.

Check whether any abstraction requires a licence. The Environment Agency requires an abstraction licence for most extraction above 20 cubic metres per day from any watercourse, lake or borehole. If you are already licensed, confirm your permitted conditions. If you are unsure, check the GOV.UK abstraction guidance now rather than in August after a complaint has been logged.

Test the system before it matters

Walk the site with a simple map and mark the irrigated zones. Then mark everything else. Most sites have accumulated gaps: areas that were once covered but fittings were removed, areas added to the estate after the original system went in, or zones that a contractor managed using their own equipment and then left when the contract ended.

For automated systems, run each zone now rather than in August. Check for blocked or misaligned heads, poor coverage overlap, pressure drops at the far end of long runs, and any leaks that have quietly been losing water since autumn. A head that dribbles rather than rotates will not keep turf alive in a heat event, and the damage is usually visible before anyone thinks to check the head.

Manual watering deserves the same scrutiny. If you depend on a bowser or a hose reel, work out whether the team capacity is realistic for the area they would need to cover on consecutive dry days. It often is not.

Set priorities before the pressure arrives

Not everything on site needs the same response to dry weather. Fine sports turf, recently seeded areas and newly planted trees are the most vulnerable. Established rough areas, native species mixes and wildflower swards generally tolerate summer dryness better and often recover without intervention. The problem with irrigation decisions made during a heat event is that they tend to water everything equally, which means the water ends up in the wrong places.

Write a simple priority list while you have time to think clearly. Tier one: assets that cannot recover from a failed season without significant cost. Tier two: areas where some stress is acceptable and recovery is likely. Tier three: areas that can safely be left without irrigation. Knowing this in spring means your team can act quickly in July without waiting for a management decision that nobody wants to make under pressure.

Plan before you spend

If the audit shows gaps that matter, spring is the time to cost up solutions. Adding irrigation runs, extending an automated system or buying a second bowser is cheaper when there is time to get quotes and choose the right equipment. Retrofitting under pressure in a dry July is a different experience entirely.

For sites planning new seedings or turf laying later in the season, confirm now whether adequate water will be available during establishment. Seed or turf laid in late summer without reliable irrigation is a known failure point, and the best time to resolve that is before you commit to the project, not after the job is done and the weather turns.

Did you know? In a typical UK summer, grass can lose 3 to 5 mm of water per day through evapotranspiration. On a one-hectare site that adds up to 30,000 to 50,000 litres daily, which most mains connections cannot supply reliably at peak demand.

Frequently asked questions

Do I need a licence to abstract water for irrigation?

For most sources, yes, if you extract more than 20 cubic metres per day. The Environment Agency runs an abstraction licensing scheme covering rivers, lakes and boreholes. Some small-scale uses are exempt; check the current GOV.UK abstraction guidance before the summer season starts.

When is the best time to test an irrigation system?

Spring, before you need it. Run each zone in April or May, check for blocked heads, poor coverage and pressure drops, and get repairs done while there is no urgency. Testing in July when the turf is already drying out gives you far less room to act.

Should I water established wildflower areas in a dry summer?

Usually not. Established native wildflower mixes are adapted to UK summer conditions and can be harmed by irrigation that encourages rank grass to outcompete the wildflowers. Focus water on new seedings and recently planted trees instead.

How much water does an amenity lawn need in dry weather?

Around 25 mm per week is a rough guide to maintain active growth on a free-draining site, though this varies with grass species, soil depth and how much moisture deficit has already built up. Your agronomist can advise on application rates for your specific conditions.

What if my irrigation system does not cover all of my priority areas?

Hire or buy a bowser and plan manual routes now. Spring is when hire equipment is most available and delivery times are shorter. Also decide which uncovered areas can tolerate some stress without serious long-term damage and record them as lower priority in your watering plan.