So regardless of what regs the State Board decides on, how are we going to reduce CA urban water use by 25%? With typical Jerry Brown flair, the Governor puts the big idea directly: “The idea of your nice little green lawn getting watered every day, those days are past.”
One challenge to getting there: water managers often don't know where lawns are and who's taken out their lawn in favor of California native landscaping outside of the formal utility sponsored cash-for-tearing-out-your-grass rebate programs.
How can we manage what we can't measure?
Many forward thinking utilities use aerial imagery and in fact sometimes commission their own aerial surveys to quantify the types of vegetation in their service area.
With that raw image data in hand, it's possible to use GIS parcel lines to clip the tagged area
Below we offer an illustrative example of what it looks like to use ESRI arcGIS aerial imagery to tag lawn areas in the City of La Canada (aka this Argonaut's hometown, kinda sorta ) .
One problem with this approach? Trees.
It's hard to know whether a home has a lawn if their yard has tree cover above. So we've started a demonstration project with La Canada to show how google streetview could be used to identify lawns.
We pulled images for every address in La Canada that the US Postal Service showed as valid and then used a few thousand Amazon Mechanical Turks to classify the images for $0.02 a pop. All in all ran us about $250 and resulted in what's below.
Hey Google why not do this for all of California?
Our problem: the Google Streetview AP doesn't let us get the date the Streetview image was taken or historical images. So we can't build a time series of images to show the changes.
Luckily we hear you guys are all about not being evil and are not bad at classifying images. So what do you dudes say? You down to help California deal with the drought?
Patrick and Varun
 Re: Patrick's hometown: Given the fact that this is California local government we're talking about, it's not a simple story.
I technically grew up on Ocean View inside La Canada City limits but went to Glendale schools and played high school football for Crescenta Valley in La Cresenta. The current effort to consolidate the school district lines along the City boundaries has a nice history of the barnacled administrative architecture that governs my home.
Oh and PS there's also the four water districts that serve La Canada. Tell you: truth is stranger than fiction. Especially when it comes to California government.