DEPARTMENT: Planning and Community Development
DEPARTMENT HEAD: John Dugan
COUNCIL DISTRICTS IMPACTED: City-wide
SUBJECT:
Briefing and discussion on impervious cover regulations for newly annexed territory.
SUMMARY:
Briefing and discussion on impervious cover regulations for newly annexed territory.
BACKGROUND INFORMATION:
On September 11, 2015, District 8 Councilman Ron Nirenberg filed a memorandum to the Mayor and City Council on the need to address the City’s impervious cover policy and the potential negative impact should annexation allow more impervious surface coverage over the Edwards Aquifer Recharge Zone.
On September 30, 2015, at a City Council “B Session” related to the five priority annexation areas, staff recommended referral of the impervious cover issue for newly annexed territory to the Neighborhoods and Livability Committee. On October 19, 2015 the Neighborhoods and Livability Committee reviewed impervious cover in newly annexed areas. The impervious surface cover discussion was further referred to the Comprehensive Planning Committee, incorporating responses to questions raised by the Neighborhoods and Livability Committee.
ISSUE:
The development of land above the Edwards Aquifer Recharge Zone is managed, in part, by the City’s Water Quality Ordinance in Chapter 34 of the City Code. The ordinance sets maximum impervious coverage limits for new development on properties in the City limits and the City’s extraterritorial jurisdiction. More impervious cover is currently permitted within the City Limits than in the City’s extraterritorial jurisdiction. Maximum impervious cover in unincorporated Bexar County is 15% for all development. Within the City Limits, the maximum impervious cover ranges from 30% for residential single family subdivisions, 50% for multi-family development, and 65% for commercial development.
Projects currently considered Category 3 with restrictions on development at 15% impervious cover, will become Category 2 if annexed and brought into the City limits. Category 2 allows increased impervious cover of 30% for residential single family subdivisions, 50% for multi-family development, and 65% for commercial development. The Council may wish to consider including language in the annexation regulatory plan that does not extend Category 2 classification to newly annexed area for limited purposes, which would be adopted with annexation action. Additionally, City Council could elect to bring forward an amendment to Chapter 34 to provide the same regulation for properties annexed for full purposes.
The City’s Water Quality Ordinance was developed based on scientific studies showing that minimal pollutants collect on impervious cover in properties with 15% impervious cover or less. As the amount of impervious cover increases above 15%, additional treatment of storm water runoff is required. Accordingly, Category 2 properties which have greater than 15% impervious cover are required to implement best management practices (BMPs) to treat storm water runoff. Typical BMPs used include water quality basins that remove contaminants from runoff through the use of sand filters or proprietary cartridge filter systems, vegetated bio-swales and filter strips, and drainage inlet or manhole filters. These common types of BMPs are designed to remove targeted amounts of suspended solids and contaminants from storm water runoff prior to discharging into a creek or channel. Since Category 3 properties have less than 15% impervious cover, BMPs are not required by Chapter 34.
ALTERNATIVES:
Staff will discuss possible alternatives at the briefing.
FISCAL IMPACT:
There is no fiscal impact associated with this item.
RECOMMENDATION:
This is a briefing for informational purposes only.