some twit starts a fire,
they use the lake water to put out the fire,
the water levels drop significantly,
blue/green algae blooms more often and with more intensity That's a story I can apply to a dozen odd lakes locally
only instead of a fire its shires using the water for road construction etc etc.....
Lake Bolac for example is being drained by the tanker load by Arrat/Stawell shire on a daily basis, a local told me that on average they take around 4 tanker loads a day, 7 days a week
.
You'll need more than one case of Shiraz though. 