New report highlights need for better water use data

The Canterbury Water Use Report (2010/11) – released by Environment Canterbury at the Irrigation NZ Conference in Timaru – highlights the need for consent holders to install water measuring systems and to ensure they are working properly.

“We need good quality data on water use in order to better manage and allocate the huge freshwater resource we have in Canterbury,” said David Caygill, Environment Canterbury’s Commissioner with responsibility for water.

The report highlights that across Canterbury 33.7 per cent of the 7022 consented groundwater wells were equipped with water measuring devices by the end of the 2010/11 water year. For surface water takes 19.7 per cent were equipped with water measuring systems.

“When we looked at the data we found, however, that only 801 wells – or 11.4 per cent – had reliable records from at least 250 days and with 90 per cent of the 15-minute or hourly measurements captured.” 

“We need a much better reliability of data to inform our decision-making on water management and allocation.

Based on the data available 52.4 per cent of allocated groundwater was used during the year while 49.5 per cent of consented volume of surface water takes was used (based on just 7.7 per cent of the region’s surface water takes).

Given the predominant use for water in Canterbury is irrigation – for agriculture and horticulture – and that the rainfall trends during the 2010/11 period was average the proportion of water allocation used is lower than what would be experienced during drier years.

From 10 November this year all water takes of 20 litres a second or more will be required to have water measurement systems as required by the Government’s Resource Management (Measurement and Reporting of Water Takes) Regulations 2010. Consent holders are also required to supply water use data on an annual basis to their relevant regional council

“Given the implementation of the national regulations Environment Canterbury will have greater amounts of information on water use in coming years.

“The significance of these regulations to Canterbury is illustrated when you consider that 97.4 per cent of all daily allocated groundwater and 99.3 per cent of all daily allocated surface water is contained in takes of 20 litres a second or more.”

For those who need more information about water measurement systems Environment Canterbury has staff members available to provide practical advice to water users. In addition there is also plenty of information on the Environment Canterbury website including a full list of approved service providers for the installation and maintenance of water measuring systems.

Within the Water Use Report there is an update for each of the Canterbury Water Management Strategy zones on the progress towards installing water measuring devices during the 2010/11 year. In addition, information on water allocation and actual water use is provided (where available) for each of the zones. 

“This information will be very useful to the 10 zone committees as they formulate their programmes of recommendations for Environment Canterbury.

“These recommendations will ultimately get reflected in river and catchment plans, as well as the regional plan for land and water management,” said David Caygill.

The Canterbury Water Management Strategy – the collaborative process set up to provide a better system based around community needs – sets targets for improved water efficiency and irrigation, as well as targets for better environmental and cultural outcomes resulting from more water in rivers and better water quality.

“Irrigation is the primary use for water in Canterbury and accounts for around 84% of consented water use. It drives agricultural production and is of huge importance for communities and businesses throughout the region.

“We simply have to get our water management right and having reliable and widespread information about actual use is essential,” said David Caygill.