That expenditure is in addition to the $67 million it cost to build the scheme to deliver water from the Waitaki River to farms.
The biggest expenditure has been to convert farms to dairying, which now makes up more than half of the 10,000ha covered by the scheme.
These details are revealed in a report commissioned by the Waitaki Development Board from consultants AgriBusiness Group to investigate the economic benefits from the scheme, now in its fifth season.
The scheme uses a canal from the Lower Waitaki Irrigation Company's intake at Bortons to take water to a pond and pumphouse next to State Highway 83 which through pipes, canals and storage ponds delivers water to the farms.
On Thursday, the Otago Daily Times reported the new scheme had boosted farm income by $44 million a year and created 76 farm jobs as a result of irrigation.
That has resulted in farmers spending almost $30 million more a year, most of it in the local community.
Board chairman Peter Robinson described the scheme as "the single most significant economic development" project in North Otago in recent years.
The full report indicates farmers who are taking water from the scheme have so far invested $62.24 million in their properties.
Irrigation has resulted in a significant shift to dairying from the more traditional dryland farming, which was prone to droughts.
North Otago Irrigation Company chief executive Robyn Wells said the report showed the benefit of this irrigation scheme and others to the North Otago economy now and for the future. For example, in times of drought, farms had been able to continue producing where once they had not. The whole community benefited.
Along with that, farms on the North Otago scheme had to have individual farm environment plans covering a wide range of management issues, including efficient application of water, fertiliser application and effluent management.
The company had an employee who spent three days a week monitoring those plans to ensure they complied, a requirement of the resource consents the company held, she said.
"Those plans allowed farmers to grow their business while preserving the environment through the application of standards and practices that will contribute to the environment on a long-term basis," she said.
Before the scheme, 2075ha of the 10,000ha was in dairying. Now, 5820ha is dairying, mostly at the expense of sheep farming.
That has resulted in a sheep farming drop from 5199ha to 1023ha after irrigation, dairy support from 1211ha to 933ha, and arable from 1241ha to 1193ha. Beef has increased from 179ha to 883ha and there is new deer farming at 60ha.
The report said there would have been some change without irrigation away from traditional land use of sheep and beef farming towards dairy support.
However, with irrigation there had been "a significant move to dairy farming", now making up about 60% of the 10,000ha.
There had been a substantial change in land ownership during this time.
Changes in land use required a lot of expenditure on development other than irrigation itself.
Changing to dairying was estimated at $10,915 a hectare, dairy support $2240, sheep and beef $4390 and arable $2920.
In terms of conversion costs, the biggest expense was putting in the farm irrigation system, estimated at almost $22 million of the $62.24 million.
The next biggest expense was livestock at almost $16 million, followed by cow sheds at $11.24 million.
These three costs made up almost 80% of the investment.
However, dairy provided the biggest return for the capital invested.
Milksolids earned $34.11 million of the extra $44 million a year in farm income with irrigation, cattle $4.25 million, arable $2.86 million and dairy support $1.15 million.
The report said that although there had been a slight drop in arable land with the new scheme, irrigation had brought a significant increase in output.
WATER WONDER
Irrigation scheme farm investment:
• On-farm irrigation $21.81 million.
• Livestock $15.94 million.
• Cow sheds $11.24 million.
• Regrassing $3.32 million.
• Housing $2.56 million.
• Fertiliser $1.99 million.
• Machinery $1.95 million.
• Fencing and lanes $1.57 million.
• Other buildings $600,000.
• Stock water $480,000.
• Clean up $390,000.
• Electricity supply $370,000.
• Other $200,000.
Total: $62.24 million.
