Hi Rebecca - great to have you on the forum! Speaking for California, we have some interesting water issues involving our MS4 permitting. It's not my area of expertise but I understand that newer developments (at least in San Diego, where I'm at) have to retain runoff from the 85th percentile storm event onsite. I believe that all non-stormwater runoff now has to be retained onsite. The heightened requirements for onsite retention have affected water regimes in our urban rivers/channels, e.g., availability of stormwater and non-stormwater flows to downstream restoration areas. Look forward to hearing any perspectives you're able to share!