The environmental provisions in the groundwater sharing plans are based on:
- protecting the long-term storage component of each aquifer
- reserving 95-100 per cent of the average annual recharge in high conservation areas, such as national parks and nature reserves, for the environment
- reserving a proportion of the average annual recharge in the remaining part of the aquifer for the environment
In addition there are provisions in the Water Management Act 2000 (in section 324) to set local restrictions on pumping at certain times to protect the environment, for example if water level drawdowns below a specified level are occurring or water quality is declining. Distance limits are also set between bores and groundwater dependent ecosystems. These distances are based on the aquifer type and the nature of the dependent ecosystem.
Over the long–term, reducing the storage of an aquifer, that is permanent mining of the resource, could affect its stability and integrity, and could cause land subsidence. The aim of the water sharing plans is to ensure that this does not occur. In addition the volume of water, usually from infiltration of rainfall or river flows, that enters or recharges the groundwater system each year is important for replenishing supplies and supporting dependent ecosystems. As a result, based on the extent of the groundwater dependent ecosystems, a proportion of the recharge is allocated to the environment and the remaining proportion defined as the long-term average extraction limit (or "sustainable yield") – that is the amount of groundwater that can be extracted.
In some groundwater systems in NSW, the water allowed to be extracted (that is, the current licensed entitlement) is more than the sustainable yield of the aquifer. These water sharing plans include a process for reducing total entitlements in any over–committed groundwater system to the sustainable yield over the ten years of the plan. This is mainly the case in the plans finalised in 2006 to 2008 for the major inland alluvial aquifers – the Upper and Lower Namoi, Lower Gwydir, Lower Macquarie, Lower Lachlan, Lower Murrumbidgee and Lower Murray groundwater systems.
Achieving Sustainable Groundwater Entitlements Program
To assist licence holders in adjusting to reduced entitlements, a program of financial assistance known as the Achieving Sustainable Groundwater Entitlements Program was developed in 1995.
In this section
- Sustainable yield
On this page
- Achieving Sustainable Groundwater Entitlements Program
- More information