There are 20 hydrants on the Barrhill Chertsey scheme between Highbank and Mayfield, two in the Valetta scheme (there will be 10) and plans to fit 48 into the Ashburton Lyndhurst scheme as it is upgraded and piped.
The hydrants are a 50/50 venture with the schemes and the Ashburton District Council.
Council emergency management officer Don Geddes said that with the shutdown of water races, fire crews would now have access to on-farm water.
The location of all hydrants was in the district fire plan, and crews were encouraged to familiarise themselves with the hydrants.
A hydrant on the Barrhill Chertsey scheme at Ashburton Forks was the prime source of water during a large grass fire which burnt about 92ha on January 2. That fire tied up crews for several days.
Even when crews established other access points, the hydrant was still used.
Mr Geddes said the hydrants cost about $1200 each - the 48 in the Ashburton Lyndhurst upgrade might cost about $64,000 - and the hydrants were owned by the irrigation companies.
''There's only water in them in summer [irrigation season] but that's when we need them,'' Mr Geddes said.
The hydrants would be welcomed also in the lower part of the district, the driest, but those in use, and those planned, were valuable tools in a scorching summer with a high fire risk, he said.
The high-volume pumps used by firefighting units were too much for most water races these days.
Money for the expanded hydrant scheme has been included in the council's draft long-term plan to be sent out in April for consultation.
