Two changes to the Otago Water Plan – one affecting the Pomahaka River and the other the Cromwell terrace aquifer – have taken legal effect and are currently open for submissions.
The Pomahaka plan change proposes establishing minimum flows, allocation limits, and monitoring sites for the river, while the Cromwell plan change recommends a maximum allocation volume for the aquifer.
Minimum flows ensure that economic use of water continues and that enough water remains in our lakes and rivers to maintain their aquatic ecosystems and natural character. Allocation limits are set to avoid over-allocation and ensure good surety of supply for water takers.
Changing land use within the Pomahaka has resulted in increased demand for water for out-of stream uses, mainly irrigation. Several existing takes have had minimum flows applied to them on a case-by-case basis.
A 3600 litres per second minimum flow is proposed for the Pomahaka, in summer, to give consent holders a 99 percent expectation of supply and protect instream values from takes in a dry year.Submissions on both plan changes close with ORC on September 12.