Responding to the Environment Agency's consultation on the national Water Resource Strategy for the next 25 years, the Assembly said the strategy needs to consider the South East's special circumstances.
The south east - a relatively dry regions - will grow significantly in the next 20 years.
It says there should be:
- A 20-year planning vision to match long-term investment. This would include building new reservoirs.
- Continue to encourage prudent water use, and extend hosepipe bans.
- Reduce carbon emissions when supplying and treating water, and avoid high energy use techniques, such as desalination, where possible.
Assembly Chairman Cllr Keith Mitchell said, "The South East region needs to deliver growth and this is bound to contribute to increased use of our water resources. We therefore need to tackle this from all sides. It is essential that the Environment Agency, the water companies and other groups work with the Assembly to help deliver the region's water needs in a timely and sustainable way.
"The region also has a challenge in the face of climate change. South East residents are using less water than previous years but we should try to do better. It is about managing our need and our environment," he said.
In 2005/6, metres households used 148 litres of water per person per day, and unmetered households used 166 litres per person per day. The South East's draft Regional Sustainability Framework sets a target of 135 litres per person per day by 2016.