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Environmental Impact Assessment
7101 Huebner Road
Leon Valley, Texas 78238

Description of Project
The purpose of this project is to provide background environmental information for effective land management.  The site is prime real estate property and this research will determine the environmental impacts of such development.

Description of Site
The absolute location of the site is 29°30’ North Latitude, 98°37’30” West Longitude and the topographic quadrangle maps used were Castle Hills, Culebra Hill, Helotes, and San Antonio West for the state of Texas.  The Universal Transverse Mercator (UTM) coordinates are 3263000m North, 536000m East and zone 14.  The SPCS Texas Coordinate System coordinates are 610000ft North, 2120000ft East and the south-central Texas zone.  (see Topographic Maps A-D).

The site is located at 7101 Huebner Road, Leon Valley, Bexar County, Texas (see Map 1).  Leon Valley is an incorporated town of San Antonio.  It is owned by Sundance Financial Inc. located at 2505 Congress St., Suite 220, San Diego, California.  (Bexar 2003).  This site is 7.4480 acres with approximately 40 small slabs of concrete, possibly an old mobile home community.  There are no buildings, a couple small remnants of old fencing, one large tree and multiple small trees.  There is one well, but it is unknown whether it is septic or a water well.  There are two large sink holes approximately 4 feet in diameter with one having two pipes that empty into it.  There are multiple wires protruding out of the ground throughout the property next to the concrete slabs.  There is a small road that runs along each side of the property (see Map 3).  There is a drainage ditch and multi-family housing currently being built that borders the northwest end of the site.  A school on the northeast end with a single-family housing subdivision on the southeast.  A shopping center including a car repair shop to the west and a gas station on the southwest ends of the site.  The entire site is approximately 0.15 miles in length.

Natural Environment
The highest elevation in the study site is 870 ft. (265 m), the lowest is 860ft. (262 m), with a relief of 10 ft. (3 m).

The stream that drains the site is Huebner Creek, stream segment 1907.  (TCEQ2 2003).  It first enters Leon Creek then the San Antonio River all within Bexar County.  The San Antonio River enters the Gulf of Mexico at San Antonio Bay giving a direct distance to the coast of approximately 270 miles (435 km.) (see Map 4).  The San Antonio River Basin is the major river basin of the area and the San Antonio River Authority is the area’s official river authority. (TCEQ1 2003).  The Texas Water Development Board planning region is Region L – South-central Texas and the groundwater conservation district is the Edwards Aquifer Authority.  (TWDB 2003).  The source of water for the site is the Edwards Aquifer and precipitation.  The major water quality problems would be sulfate and there is no waste-water disposal method.  (TCEQ2 2003).
Geology and Landforms
The geologic mapping code is Kau and the mapped unit is Austin Chalk.  The major rock types consist of chalk and marl.  The area is 70-100 million years old leaving it in the Mesozoic Era, Upper Cretaceous Period. (University 1983).  The geologic hazards consist of sinkholes and flooding and there are no mining activities or resources.  The landforms of the area are in the Atlantic and Gulf Coastal Plain Province, Western Gulf of Mexico Section, and the Black Prairie District.  (Fenneman 1931).   The closest major landform feature is the Balcones Escarpment.  (Riasz 1957).

The nearest weather station that had a long term record was the San Antonio Intl Airport, Texas weather station.  The years of record for climate records were 1933-2002.

                                Temperature               Precipitation
January mean 48.1°F 8.9°C  2.04 in 51.82 mm
February 52.1°F 11.2°C 2.27 in 57.66 mm
March 60.2°F 15.7°C 1.81 in 45.97 mm
April 68.3°F 20.2°C 2.83 in 71.88 mm
May 74.7°F 23.7°C 4.98 in 126.49 mm
June  80.4°F 26.9°C 4.20 in 106.68 mm
July 83.2°F 28.4°C 2.12 in 53.85 mm
August 83.4°F 28.6°C 2.30 in 58.42 mm
September 78.3°F 25.7°C 3.71 in 94.23 mm
October 69.2°F 20.7°C 3.12 in 79.25 mm
November 59.4°F 15.2°C 3.09 in 78.49 mm
December 51.1°F 10.6°C 2.08 in 52.83 mm
Year 67.4°F 19.7°C 34.55 in 877.57 mm
 (NOAA 1999)

The record highest temperature was set on September 5, 2000 of 111°F (43.9°C).  The coldest temperature on record was –2°F (-18.9°C), which was set on January 31, 1949.  The wettest year was in 1998 with 58.51 in. (1486.15 mm) for the entire year.  The driest year was in 1954 with only 13.42 in. (340.87 mm) for the year.  (NOAA 1999).  The 100 year, 24 hour storm is 10 in. (254 mm).  (Hershfield 1961).

Using the Thornthwaite method of determining average potential evapotranspiration the average is 3.46 in. (87.9 mm).  (Malmstrom 1969).  While using the Penman method the average is 98.42 in. (2500 mm).  (Texas A&M 1983).

The date of the last frost in Spring is around March 15 and the average date of the first frost in Fall is around November 15.  This gives the average length of the growing season to be 246 days.  (Baldwin 1973).

The climate type Koppen code is Cfa and the climate name is Humid Subtropical.  This describes the area as having hot summers, cool/mild winters, and year-round precipitation.  The major climate hazards of the area are fire, lightening, tornadoes, drought, flood, and hail.  (Hudson 2000).
(USDA 1984)
The soils of the study area are mainly comprised of AuC, Austin Silty Clay 3-5% slopes; BrD, Brackett soils 5-12% slopes; and TaB, Tarrant Association gently undulating 1-5% slopes.

The Austin Silty Clay is comprised of shallow to moderately deep soils.  The soils are located on the Rolling Blacklands range site.  The soils tend to drought easily, thus very susceptible to water erosion.  The soils are well suited for crops, such as, corn, small grain, hay and pasture or native grass. The soil taxonomic classification for Austin Silty Clay is:
 Order                        Mollisols
     Suborder               Ustolls
         Great Group      Haplustolls
              Sub-Group   Udorthentic
                  Family      Fine-silty, carbonatic, thermic
                      Series   Austin
The Brackett soils 5-12% slopes are comprised light-colored, very shallow, calcareous soils that develop over chalk.  Rock outcrops are located on the tops and upper side slopes of meandering rivers in the Adobe range site.  They have stones, gravel, channery fragments, and cobblestones on the surface and in the subsurface.  These soils are best suited to native grass.  The natural fertilization is low, it has rapid runoff and active erosion even in vegetated areas.  The soil taxonomic classification is:
 Order                        Inceptisols
     Suborder               Ustepts
         Great Group      Haplustepts
              Sub-Group   Typic
                  Family      Loamy, carbonatic, thermic, shallow
                      Series   Brackett

The Tarrant association, gently undulating soils are comprised dark-colored, very shallow, calcareous and clayey soils that develop over hard limestone.  The soil occurs in the Rocky Upland range site of prairie and plateau area that are nearly level or gently sloping.  They have stones, gravel, channery fragments, and cobblestones on the surface and subsurface.  These soils are best suited to native grass.  The main limitations are water erosion and lack of soil moisture.  The soil taxonomic classification is:
 Order                        Mollisols
     Suborder               Ustolls
         Great Group      Calciustolls
              Sub-Group   Lithic
                  Family      Clayey-skeletal, smectitic, thermic
                      Series   Tarrant

The major terrestrial ecosystems are Mesquite-Live Oak-Bluewood Parks and commonly associated plants (see Map 5).  They are dominant woody plants that grow about 9 feet tall or more.  They grow as clusters or scattered individuals within continuous grass or forbs.  They are 11% to 70% woody canopy cover overall.  (McMahan, et al. 1984).
 Landuse and Natural Environment Inventory

Present Day Landuse
The site is currently a vacant lot, most likely an old mobile home community.  There are trees growing through some of the concrete slabs, thus the site has been vacant for some time.  It is not currently being utilized for anything useful except for collecting trash from adjacent property owners.

Future Landuse Values in Demand
The site is a highly desirable real estate property possibly extending the multi-family units from the northwest side or extending the single-family subdivision from the southeast side.  It could also be used as commercial property or it could also be useful to the school located the north boundary as an expansion.

Water Inventory
There would not be a significant increase in water demand since this site is very small.  The threats to water quality and quantity would be the possibility of contamination of the Edwards Aquifer.  The San Antonio Water System and Bexar Metropolitan Water District would regulate the water usage.

Climatic Inventory
Development of this site would not cause any greater air quality problems.

Biological Inventory
There are no endangered or threatened species listed for Bexar County on the Texas state list.  (Texas Biological 2001). There are a significant amount of endangered species listed on the federal list.  Endangered animal species listed on the federal list for Bexar County are the Mountain Plover, Black-capped Vireo, Golden-cheeked Warbler, two unnamed ground beetles, an unnamed spider, Government Canyon cave spider, Helotes mold beetle, Madla’s cave spider, Robber Baron Cave harvestman, Robber Baron Cave spider, and the Vesper cave spider.  There are no threatened or endangered plant species listed on the federal list for Bexar County.  (U.S. Fish 2003).  Current threats to these biota are pollution and humans.  Future threats to the biota would be the estimated development.

Cultural and Social Inventory
There are no registered historical or archeological sites with the state or nation for the study site.
(Texas Historical 2003).


Baldwin, John.  1973.  Climates of the United States.  Washington, D.C.: United States Department of Commerce.

Bexar Appraisal District.  2003.  Bexar Appraisal District Property Search.  Bexar Appraisal District; available from  Internet; accessed 25 April 2003.

City of San Antonio.  2002.  City of San Antonio – GIS Mapping Application.  COSA GIS; available from  Internet; accessed 05 May 2003.

Fenneman, N.M.  1931.  Physiography of the Western United States.  New York: McGraw Hill Book Company, Inc.
Hershfield, D. 1961.  Rainfall Frequency Atlas of the U.S. for Durations from 30 minutes to 24 hours and Return Periods from 1 to 100 Years.  Washington, D.C.: U.S. Department of Agriculture.

Hudson, J.  2000.  Goode’s World Atlas, Climate Regions.  USA: Rand McNally & Company.

Malmstrom, V.H.  1969.  A New Approach to the Classification of Climate.  Journal of Geography 68:351-357.

McMahan, Craig A.; Frye, R.G.; Brown, K.L.  1984.  The Vegetation Types of Texas.  Texas Parks and Wildlife Department; available from  Internet; accessed 02 March 2003.

National Oceanic and Atmospheric Administration (NOAA).  1999.  Annual Climatological Summary (1999).  San Marcos, Texas: U.S. Department of Commerce; available from  Internet; accessed 02 March 2003.

Raisz, E.  1957.  Landforms of the United States, sixth revised edition.  Boston: Erwin Raisz.

Texas A&M University.  1983.  Agroclimatic Atlas of Texas.  Part 6.  Potential Evapotranspiration.  College Station, TX: Texas Agricultural Experiment Station.  MP-1543.

Texas Biological and Conservation Data System.  2001.  Wildlife Diversity Branch.  County Lists of Texas’ Special Species-Bexar County.  Austin, TX: Texas Parks and Wildlife Department.

Texas Commission on Environmental Quality1 (TCEQ1).  2003.  Final Draft – 2000 Texas Clean Water Act Section 303(d) List.  Austin, TX: Texas Commission on Environmental Quality while still referred to Texas Natural Resource Conservation Commission; available from  Internet; accessed 29 March 2003.

Texas Commission on Environmental Quality2 (TCEQ2).  2003.  Draft 2002 Water Quality Inventory.  Texas Commission on Environmental Quality while still referred to Texas Natural Resource Conservation Commission;  Internet; accessed 29 March 2003.

Texas Historical Commission.  2003.  Texas Historic Sites Atlas.  Texas Historical Commission; available from  Internet; accessed 19 April 2003.

Texas Water Development Board (TWDB).  2001.  South Central Texas Regional Water Plan, Volume I, Executive Summary.  Texas Water Development Board; available from  Internet; accessed 06 February 2003.

The University of Texas at Austin(UT).  Bureau of Economic Geology.  1983.  Geologic Atlas of Texas, San Antonio Sheet.  Austin, Texas.

U.S. Department of Agriculture (USDA).  1991.  Soil Survey of Bexas County, Texas.  Series 1962, No. 12, reissued June 1991.  Soil Conservation Service.  College Station, TX:  Texas Agricultural Experiment Station.

U.S. Fish and Wildlife Service.  2003.  Endangered Species List.  U.S. Department of the Interior; available from  Internet; accessed 06 February 2003.