Margaret McGuinness, Water Quality Risk Manager at Guernsey Water, said overuse can harm the natural environment. 

“With people spending increased amounts of time in their gardens as the weather improves, it is a good time to offer advice on how to protect the local environment whilst enjoying time outdoors," said Mrs McGuinness. 

“If Islanders plan to apply either herbicides or pesticides, they should follow the professional guidelines provided and limit their usage. We would, however, encourage natural alternatives where possible for the benefit of our environment and water resources.”

Where chemicals are necessary, Guernsey Water has provided guidelines to follow even if the areas are dry at the time of application and the product labelling suggests it can be used in or near watercourses:

• Do not apply pesticides in wet or windy conditions, or if rain is forecast within a few days as these can lead to run-off and contamination;

• Slug pellets containing Met aldehyde should not be applied within ten metres of vulnerable areas;

• Direct application may be carefully used up to one metre from the edge of vulnerable areas (douits, stream banks, ponds, wet meadows, marshy areas, drainage ditches, culverts or paved areas);

• Spraying should not be carried out within three metres of a douit, stream, pond or other watercourse;

• Spraying on paved areas should be avoided, hand weeding or direct application methods are best under these circumstances;

• The commercial application of pesticides must only be undertaken by trained personnel holding a certificate of competence;

• Washings from containers must not be allowed to enter surface water gullies or drains.

Guernsey Water is advising Islanders to contact them for further advice or to report a pollution incident on 229500.