Since the passage of the City’s Tree Preservation Ordinance in 1997, the City has taken steps to address the loss of its tree canopy as well as the loss of function associated with those lost trees.  Research shows that trees assist with storm water runoff and erosion, remove pollutants from the air, reduce the heat island effect and energy use, provide a landscape and sound buffer between incompatible uses, and protect and enhance property values.  The City desires to complete a tree canopy analysis in its efforts to reduce and mitigate the impact of tree loss to meet desired environmental outcomes.

A regional tree canopy analysis of San Antonio, Bexar County, and portions of surrounding counties was completed in 2002 by American Forests, a non-profit corporation that specializes in assisting communities in planning and implementing tree and forest actions to restore and maintain healthy ecosystems.  The study concluded that the greater San Antonio area had a 22% loss of heavy tree canopy between 1985 and 2001.   In 2003, American Forests completed a second study of the City of San Antonio and its extraterritorial area and created a tree canopy mapping tool for use with the City’s GIS system.  It was recommended that San Antonio establish an overall tree coverage goal of 35% for the area, with a lower percentage in the central business district, graduating to a higher coverage in suburban areas. 

These studies were utilized to develop the 2003 amendments to the City’s Tree Preservation Ordinance where preservation of existing canopy for commercial (40% coverage) and residential (35% coverage) is required, with adjustments for preservation of tree understory.  The November 2006 Tree Preservation Ordinance amendments made further modifications to the number, types and sizes of trees to be preserved.  

On April 30, 2007, a Request for Proposals (RFP) was issued for an updated tree canopy analysis to classify, evaluate, and calculate the loss of tree canopy since 2003.  Specifically, the RFP requested the current percentage of heavy, medium, and light tree canopy coverage and an analysis of the impact of tree canopy loss on storm water, air quality, and water quality.  This tree canopy study will quantify the trend of tree canopy loss within San Antonio and its extraterritorial area.  In addition, a new canopy goal is to be recommended with a breakdown for Suburban, Urban, Central Business District, Commercial, and Residential developments.  Based on the results of this tree canopy study and the goal recommendation, the City will reevaluate its existing Tree Preservation Ordinance. 

Three responses were received and evaluated by the Selection Committee, that included professional staff representing CPS Energy, San Antonio Water System, Alamo Area Council of Governments, the Real Estate Council of San Antonio, the Greater San Antonio Builders Association, Development Services Department, Parks and Recreation Department, Environmental Services Department, Public Works Department, and the Economic Development Department rated the proposals.  Rating criteria included Experience/Qualification/Background (40 points), Proposed Plan (30 points), Price (10 points), and SBEDA (20 points). 

After initial evaluation, two firms had significantly higher ratings and the Selection Committee held interviews with these firms.  A request for best and final offers was issued and, upon receipt of that information, the final scoring was compiled with American Forests receiving the highest score.  Staff recommends selection of American Forests, a non-profit entity headquartered in Washington D.C.  This organization possesses significant experience in this field, having developed the tree canopy analysis methodology in 1993.  American Forests has completed 40 tree canopy studies across the country, including the 2002 and 2003 studies for San Antonio (noted above).  Their team includes The Sanborn Map Company and Pape-Dawson Engineers. 

American Forests will provide the City with a report detailing their findings and recommendations.  Their tree canopy mapping tool will be provided and then used by the City as a part of its GIS system.   In addition, American Forests will give a PowerPoint presentation to interested citizens and staff on their findings, recommendations, and the benefits of tree canopy goals in achieving environmental quality goals. 

Tree canopy studies are dependent upon having leaves on trees.  This requires all aerial imagery to be completed on clear days for clarity.  Subject to weather conditions, American Forests is expected to begin work in October 2007 and will be completed in September 2008.