Here is a link to a few documents including the OKC landscape ordinances, a document detailing considerations on trees and shrubs in the city
PlanOKC is the comprehensive plan regarding changes made by city planners, developers, business owners in the okc area. A good way to brush up on what is already in the works for the area.
The office of sustainability OKC has links to resources and community programs as well as a newsletter that can signed up for to get current events.
Neighborhood Alliance of OKC is another community group with programs and resources available. When I lived in OKC our neighborhood had good luck with this organization while trying to gather ourselves and raise money.
Basically, to me it seems like there are alot of people in the area who agree with you about making our green spaces more useful and less resource consuming. It is a matter of discovering who is doing what to mitigate the problems they see and then joining in with the community groups who are doing work that you appreciate the most. I hope some of these links and things help you find a comfortable way to make a difference. I used to commute from OKC to edmond in the AM and then commute all the way to Norman during rush hour, then back to OKC in the evening. It was some of the worst times. Hope your drive is more timely than mine was.