Farmers are being asked to watch where their irrigation water goes - and keep it off the roads.
Environment Canterbury principal resource management adviser Richard Purdon said several complaints have already been received, so irrigators need to adjust their aim.
''Irrigation on to roads, particularly gravel roads, is not only a waste of water but also has the potential to create safety issues for motorists.
''It is the surprise element and the force of the water that could easily startle a motorist. It is especially dangerous for those on motorcycles.
''Our staff have been receiving an increasing number of calls, especially in our Ashburton office, and our locally-based water zone officers will be responding to these on a case-by-case basis,'' Mr Purdon said.
Irrigation consent-holders are responsible for the use of water that is applied to their properties.
''Resource consent conditions authorise the use of water to a consented piece of land, not to run to waste. While we understand it can be difficult on windy days, it is still a breach of their consent.
''Irrigation system operators must monitor the use of their water and equipment to make sure the water is used in the way that was authorised and not wasted.''
Irrigation New Zealand chief executive Andrew Curtis said the two main culprits for water going over boundaries were the end guns on pivot irrigators and travelling irrigators set up too close to roads.
''Watering on to roads creates a significant safety hazard, so it's really important for irrigators to ensure they water within their property boundaries.
''My advice is to ensure end guns are set and operating correctly and regularly checked.
''When you set up your travelling irrigator, always have a set-back distance from the road,'' Mr Curtis said.
''Aside from the safety issue, people don't like seeing water being wasted by being sprayed on to roads. Farmers who irrigate do so under strict regulatory regimes, so it's important they justify their use of water by being efficient and responsible with it.''
Anyone experiencing spray on the road that is clearly coming from an irrigation system should phone Environment Canterbury on 0800 324-636. If there is immediate danger to road users, contact the police.
Central Rural Life