De la Guerra Urban Heat Island

It was good to see the Independent’s concern about global warming reflected in the stories in the May 5-12 issue. Few people are aware that the city is planning to spend a huge sum to create an urban heat island where historic De la Guerra Plaza is now.

All the grass in the plaza will be replaced with impermeable paving, which will stretch across the entire space from the Casa de la Guerra to the News-Press building to City Hall and beyond. The fact that the new paving will not be permeable to recharge groundwater has emerged in the Historic Landmarks Commission hearings on the plans to remodel and “revitalize” the Plaza.

The permeable grass and its cooling effect will be gone. Rainwater runoff will go into cisterns, and then it will go into the storm drain system. Currently there are no plans to water the new landscaping for City Hall or the Plaza with water retained in the cisterns. Brad Hess, principal project manager, confirmed that this was true in emails with me, but added, “all of this is still in concept and needs evaluating. I think it would be great to capture water and use it but the standards to make that happen can prove very challenging.”

The “revitalization” of the Plaza includes a splash pad/bubbler fountain that will use potable water. While it will recirculate some water, much will evaporate from the wet pavement. Ironically the splash pad will probably use more water than the conventional recirculating fountains that the city has turned off during this megadrought.

The “revitalization” of De la Guerra Plaza will have a negative impact on the environment, not to mention our historic cultural landscape.