The obvious solution here is to have a tiered pricing system for water, where the price per gallon increases with consumption. Increase the price of the higher tiers and/or rate of increase until consumption drops to level you need. And then you don’t need to pay government employees to drive around and inspect celebrity lawns all day.
The issues cited in the article are a direct consequence of tiered rates. Districts become disinsentivised to reduce the water use for their highest using customers because thats where they make the most revenue. They need to show water use savings in gallons, but they make far more from high using customers. Its much more cost effective (gallons of water saved/reduction in revenue) for them to target users who only irrigate in the lowest use tier because thats where they receive the least revenue per unit volume water delivered.