This is a pumped storage reservoir. They can fill it any time they want from the aqueduct. It gets very little from rain. So, it being full means nothing.
How long until the Sahara turns green again? Image result for is the sahara desert turning green The cycle is caused by a 41,000-year cycle in which the tilt of the earth changes between 22° and 24.5°. At present, we are in a dry period, but it is expected that the Sahara will become green again in 15,000 years. Sahara - Wikipedia
You are correct You know what is caused by earth axis tilt. There has been a 15% regretting of the planet has shown by satellites in the last 10 years because of excess carbon.
If it wasn’t for you know what we’d still be stuck in the last Ice Age, which only ended 10,000 years ago that created the great lakes and all the fertile farmland in North America
