No, we don't have bounties for reporting water wasters that I'm aware of. Most water districts are trying the soft approach using warning citations as an educational tool. Generally no one is fined on a first offense. Fines are for repeat violators. There is one district I read about that is really in dire straits that even offers a "Water School" along the lines of traffic school to those receiving citations that lets you work off the fine by sitting in a classroom receiving water conservation instruction.
There is a saying that dates to the 1800s that in California whiskey is for drinking and water is for fighting. This is far from the worst drought the California has experienced. Western water law is based on the concept that "first in use is first in right", meaning whomever made a claim to the water first and continues to use it has first rights to that water. Those who came later lose water in a drought. What that means is that some farm districts with water rights dating back more than a century are flood irrigating crops of rice while municipal water districts and many agricultural water districts with more junior water rights have lost their allocations of water completely. The courts have, so far, turned back every attemtp to change this situation. Fully 85% of the developed fresh water used in Souther California is owned by the Imperial Irrigation District. They take water from the Colorado River and irrigate low desert croplands through unlined dirt ditches. Because their water rights are senior to every single other Colorado River user except the native tribes, LA, Vegas and every other water user on that river will have to surrender every drop of their allocation before the IID has to give up even one drop. Fair or not, this is the law and it has survived multiple legal challenges all the way up to the US Supreme Court. I vividly recall an IID board member calling a US Senator an "overweight, pig eyed, gas bag sack of sh!t" in a public meeting with the press in the room because the Senator had the temerity to suggest that running water through the open desert in unlined dirt ditches just might not be the highest and best use of scarce water. Such are the temperaments of people with water rights.