Water is a finite resource and, as pressure on water systems continues to grow, there will be a continued drive to use current water resources more efficiently. In the South African context, irrigation amounts to between 52% and 63% of water use in the country. The proper management of water use requires an understanding of how much water is used by irrigation systems. On farm level, the installation of water meters is one tool farmers can use to optimise water use. In addition to benefits to farmers, the implementation of irrigation water measurement is encouraged by the National Water Act and the National Water Resource Strategy. New regulations for water measurement have been published.
Why is water metering essential?
- Increased water use efficiency
Metering of water use allows for the optimisation of use. It allows for a more accurate expression of use which could free up water for production expansion (optimise quota use). Additionally, water use trends (data) allow for better crop-planning while also serving as an early warning system.
- Irrigation system performance
Water metering can also be used as a tool to monitor irrigation system performance. As a source of data in a distribution network, variation in flows is used as a diagnostic tool. High or low flows suggest a fault within the irrigation system. Lower flows may, for example, indicate a leakage, faulty pump or a clogged emitter. High flows, on the other hand, can indicate damaged emitters or multiple zones functioning at the same time. Implementation of metering devices allows for more optimal management of irrigation systems.
- Legal compliance
Section 26 (b) of the National Water Act allows the minister to require water use to be monitored, measured and recorded. Continuous pressure on water resources (including catchment stress, implementation of the reserve, compulsory licensing, water allocation reform, and prolific illegal water use) could see an increase in enforcement action being taken in terms of these regulations.
- Benefits transcend farm level
Implementing water metering is not only advantageous to the user but also improves water management at local, catchment and national level. Implementation of water metering among users provides a new source of data for water managers at various levels. This data can then be used to verify compliance to water use entitlements, accurately levy water charges and provide key insights into planning in the water management area.
Increasing water use efficiency in the agricultural sector is imperative. With available water resources for agriculture dwindling, optimising water use efficiency is an important component to ensure South Africa’s food security. – Agri SA