Kapi (water) is a scarce and precious resource in the arid environment and plays an important role in Anangu life. Anangu consider that all water sources in the park are caused by or have an association with the Tjukurpa and knowledge of the location and temporal availability of water sources has always been an essential component of Anangu ability to survive when travelling through country.
There are two types of water found within Uluru-Kata Tjuta National Park, surface water and groundwater. Although much of the water found in the area remains hidden below the ground, both groundwater and surface water play a vital role in supporting cultural and environmental values in the park.
The Mutitjulu waterhole at the base of Uluru is regarded as the only perennial water source. After heavy rains surface water may be present for varying periods in the waterholes and drainage lines associated with the gorges of Uluru and Kata Tjuta and the claypans and depressions associated with the mulga communities in the park.
Rainfall in the arid zone is usually low, highly unpredictable and highly variable. Major rainfalls are rare and very important hydrologically and ecologically in recharging the groundwater systems and eliciting a massive pulse of life through the ecosystems. Surface water flow is important to vegetation communities and habitats and the placement of roads and infrastructure can potentially obstruct natural surface hydrology. The extraction of groundwater from regional aquifers needs to be managed to sustain groundwater-dependent surface water ecosystems.
Groundwater is the only reliable water supply in the region. There are two main aquifer systems. The Dune Plains Aquifer, from which the Yulara Resort draws its water supply and the Southern Aquifer that is the water supply for Mutitjulu community and the park.
Groundwater in the Southern Aquifer varies in age and bores sampled near Uluru contain ancient groundwater thousands of years old. These waters occur in deep, buried alluvial channels and in the fractures of deep rock systems. Other bores show some areas of groundwater were recharged within the last 50 years.
The Dune Plains Aquifer is related to an ancient buried palaeodrainage line or palaeoriver that at its maximum was about 60 metres deep, emanating from the Kata Tjuta area. Recharge of the Dune Plains Aquifer is associated with rare major rainfalls such as those in 1974, 1989, 1999-2000 and 2009.
Cultural water values
Tjukurpa is the foundation of Anangu culture and provides both rules and behaviour for the care and use of waterholes. Anangu recognise three main kinds of watersources. The most reliable watersource is tjukula (large waterhole) sometimes the home of a wanampi (water snake), and kapi wala (spring). Raalpa (soaks) are a fairly reliable watersource that represents a local water table in the sand of a dry creek bed or in the soil next to a rock dome. Soaks are usually fed from an underground water supply and are protected from evaporation by sand or soil. The least reliable source is the tjintjira (claypan) which is particularly susceptible to evaporation.
Shield shrimp are amazing creatures that survive in ephemeral puddles on the top of Uluru.
Shield shrimp are resilient invertebrates whose eggs are able to survive long term desiccation and exposure to the high temperatures at the summit. Once rain fills the puddles the eggs hatch and begin a new breeding cycle which needs to be finished before the water completely dries up.