As many of you may have noticed, parts of the park have been cordoned off. According to the Houston Parks & Recreation website, Sections of Ervan Chew Park will be closed while the swimming pool complex is removed and a water sprayground is built to replace it. The project should be finished during September 2010.
Richwood Place - Houston Texas 
Is there anywhere on the Houstontx.gov sight that explains what the sprayground is?
Here’s what their website says about them: http://www.houstontx.gov/parks/waterplayground.html
Looks to me like a paved area with sprinklers set up all over so that you get very wet, either standing still or running through them.