You already know the various problems and here are some solutions:
1. The government could set a few ground rules to bring back the water such as restricting the usage level of water for farms and other agricultural purposes.
2. The government could start campaigns to increase the level of tourists again.
3. The government can use artificial methods to bring back the water such as irrigation channels and pipes etc. (if there is any excess water)
Once the water returns, then the number of birds should increase by a large number as before the water shortage in a few years time.