Droughts & floods
Drought is an intrinsic part of the Australian landscape. With one of the most variable rainfall climates in the world, severe drought affects some part of Australia about once every 18 years. Intervals between severe droughts have varied from four to 38 years and the impacts of climate change will mean more prolonged dry periods, particularly in inland areas of NSW.
Low flows and critical water planning
The department plays a vital role in managing, allocating and protecting the water resources of NSW, especially important during times of low flows and drought.
During periods of drought, water sharing plans may be suspended. Incident Response Guides (currently in development by the department) will come into full effect and the Minister will take advice from Critical Water Advisory Groups who will respond to valley-specific needs, consistent with our state-wide policy. When flows increase, water sharing is conducted as close to the plan rules as possible, in preparation for plan recommencement.
Domestic water restrictions
During drought conditions, the department may restrict the use of surface and groundwater for domestic purposes (under s324 Order Water Management Act 2000) to the same level as local council water restrictions.
Town water supply
The department works in partnership with local water utilities in regional NSW to manage town water supplies during drought.
The department is currently developing an extreme events policy for the state and incident response guides for all surface and groundwaters in the Murray Darling Basin, to manage water quantity and quality during drought. As the Incident Response Guides extreme event management requirements of the Basin Plan (section 1.1) focus on water availability and water quality, floods are not included in these guides.
In the case of a drought event, the management response will involve progressively introducing more stringent measures to support the highest priority needs as the event becomes more critical.
For water quality events, management responses will be guided by the type of event, which can be varied and which are often managed by parties other than the department.
Water availability during high flows or flood
During periods of high flow, water is shared in accordance with the water sharing plan.
In the case of very high and flood flows, the department works with WaterNSW and the State Emergency Service to manage flows and provide timely information to affected communities.
Monitoring water during flood
Data collection and dissemination plays a crucial role in day-to-day water management activities across the state. During flood events this role becomes even more critical for both flood forecasting and flood management.
The department's network of over 700 telemetered water monitoring sites is a critical element in decision making by key agencies such as Bureau of Meteorology and the State Emergency Services.