What do you do if you have just had a new lawn laid and it needs to be watered? Well, the regulations will allow lawn watering during a hosepipe ban (technically a Temporary Usage Ban or TUB). Newly laid lawns can be watered for the first 28 days using sprinklers, provided the lawn has been laid by a business – not the homeowner.
Here is a quote from the Thames Water website:
What if I’ve just laid/sown a lawn or planted things?
You can only use a hose or sprinkler if the laying, sowing or planting was completed by a business as a service. In this case, hose use is allowed for the first 28 days from the day of planting, sowing or turf laying. The hosepipe must only be used on the new planting, and not elsewhere.
After 28 days, you must stop using a hose. You can still use a watering can instead (or an irrigation system).
There are sometimes variations between water companies, so it is important to always double check with your local provider

Options for lawn watering during a hosepipe ban
If you do need to water newly turfed areas then we recommend a high efficiency sprinkler and also a timer to allow watering during the night to minimise evaporation.
It is also a good idea to split the watering up into smaller chunks with some time between, so that the water is better absorbed into the turf. For example, instead of running the sprinklers for 30 minutes, three 10 minute watering cycles with and hour between would improve water absorption and reduce water run off.
The Access Temporary Lawn Watering kit is ideal for lawn watering during a hosepipe ban