|SECTION II ENVIRONMENTAL SETTING
The City of Santa Rosa is located in Cameron County, in the southern part of Texas, near the Rio Grande. The Rio Grande separates Cameron County from the Republic of Mexico. The City of Santa Rosa is located in the Lower Rio Grande Valley (LRGV) area at the intersection of FM 506 and SH 107, 6 miles north of La Feria and 10 miles northwest of Harlingen, Texas. The City of Santa Rosa is approximately 2.5 square miles in size and was incorporated on January 16, 1929 under the Councilman form of government. The name of Santa Rosa comes from the Santa Rosa Ranch operated by Charles Stillman in the 1860s.
There are a total of 16 designated colonias within the Santa Rosa project area: SR 1 through SR 16. The area within the incorporated city limits of Santa Rosa is designated as SR 5. Residents within SR 5 are already receiving water and wastewater services from the City of Santa Rosa, and the City has recently extended water service to SR 7 and SR 8. The 15 colonias outside of the city limits are referred to as the “planning area colonias” for the purposes of this EID.
(A) DESCRIPTION OF THE EXISTING ENVIRONMENT
(1) Geological Elements
Santa Rosa is located in northwestern Cameron County, within the Rio Grande delta and north of the Arroyo Colorado. The Rio Grande Valley is not truly a valley but a broad delta with a single existing distributary, the Arroyo Colorado, which is now disconnected from the river. Topography within the planning area is relatively flat with one significant exception. The most apparent topographic feature is the Tiocano Lake Bed, a group of sinuous Pleistocene stream meanders in the Beaumont Formation that is only partially filled (TWDB 1994). The Tiocano Lake forms a depression that is approximately 5 to 10 feet below the surrounding terrain at an elevation of approximately 40 feet above sea level. Elevations in the planning area range from 50 to 55 feet above sea level (U.S. Geological Survey [USGS] 1970 and 1982) (Figure 2 1).
Cameron County is located within the Gulf Coastal Plain of Texas within the Rio Grande fluvial deltaic system. The subsurface geology is characterized by sub parallel bands of Quaternary sedimentary rocks and unconsolidated deposits. These include deposits of Pleistocene Age (approximately 3 million years old) and Holocene Age (about 10,000 years old). These sediments were deposited and rock formations generated as the shoreline progressively receded east to the present boundaries of the modern Gulf of Mexico. Relatively young rocks are exposed at the surface along the coast with progressively older rocks and sediments exposed to the west. The older depositional systems, the Lissie fluvial system and the older Beaumont delta system, were deposited more than 100,000 years ago. The younger systems, the Raymondville and a contemporaneous delta system, were deposited during a later interglacial stage. About 30,000 years ago, sea level was lowered about 450 feet and a broad, deep valley was produced by the Rio Grande (Bureau of Economic Geology 1980). Approximately 18,000 years ago, sea level rose and the Rio Grande Valley was filled by a sequence of fluvial (river laid), deltaic, estuarine, and marine sediments (Bureau of Economic Geology 1980). The rocks of the Gulf Coastal Plain of Texas are all sedimentary clastics in origin.
Structural and tectonic features also parallel the modern coastline. Although tectonic activity increases to the west, there are portions of major fault zones in Cameron County. The Willmar Fault Zone crosses Kenedy, Willacy, and Cameron counties and is present in the vicinity of Santa Rosa. These fault zones do not have surface expression within the Gulf Coastal Plain. The tectonic setting of the Gulf Coastal Plain is characterized by simple gravity subsidence caused by the increase in thickness and weight of sedimentary beds in the direction of the coastline. The episodic progradation and faulting occurred throughout the Cenozoic. Down to the coast or gravity faults are the result of deposition and sedimentary dip in the coastal direction. The Gulf Coastal Plain has had a long history of petroleum exploration and oil and gas development activities. The Lacy Mercedes gas field is approximately 2 miles west of Santa Rosa. Other energy minerals include coal (lignite) and uranium (USACE 1999).
In the planning area, the dominant surface geology is controlled by Rio Grande deltaic deposition of sand, silts, and clay materials. The Tiocano Lake is a group of sinuous Pleistocene stream meanders in the Beaumont Formation that are only partially filled. Overlying these deposits and surrounding Lake Tiocano is a Modern eolian sand sheets exhibiting strong relict grain of base leveled dunes (TWDB 1994). Although these dunes have almost vanished as a result of agricultural activity, they are apparent as southeast to northwest trending lineations and as locally sandier soils at the surface. Santa Rosa and the immediate vicinity are underlain regionally by typical floodplain mud veneers overlying a Pleistocene meanderbelt sand (TWDB 1994).
The Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service, evaluates soils as to their applicability for specified use. The specified uses included in this report are for sanitary sewage facilities, specifically limited to septic tank absorption fields. Septic tank absorption fields are areas in which effluent from a septic tank is distributed into the soils through subsurface tiles or a perforated pipe. The ratings are based on soil properties, site features, and observed performance of the soils. Factors that affect the performance of septic tank absorption fields include permeability, a high water table, depth to bedrock or to a cemented pan, frequency of flooding and loading. Permeability affects the rate at which water or effluent percolates through the soil. Slow percolation means that the slow movement of water may adversely affect the specified use.
A failing septic tank absorption field, which includes excessively slow absorption of effluent, surfacing of effluent, and hillside seepage, can affect public health. A septic tank absorption field can also pollute groundwater if highly permeable sand and gravel or fractured bedrock is less than four feet below the base of the absorption field, if the slope of the soils is excessive, or the water table is near the surface. A properly functioning absorption field requires that unsaturated soil material be present beneath the field to effectively filter the effluent.
Limitations on the use of soils for septic tank absorption fields are characterized by the NRCS as slight, moderate, and severe. A slight classification indicates that soil properties and site features are generally favorable for the indicated use and limitations are minor and easily overcome. A moderate classification indicates that soil properties or site features are not favorable for the indicated use, but special planning, design, or maintenance could be used to overcome or minimize the limitations. Classification as severe indicates that soil properties or site features are so unfavorable or so difficult to overcome that special design, significant increases in construction costs, and possibly increased maintenance are required.
Soils vary with the parent material and the topography. Correlating roughly with sand sheet deposits, the soils of the Hidalgo Raymondville Association are present in the planning area and are characterized by deep sandy clay loams and calcareous clays that are well drained. In the Santa Rosa area, the Raymondville series predominates. The 10 soil types found in the planning area colonias include Benito clay (BE); Hidalgo fine sandy loam, 0 to 1 percent slopes (HGA); Hidalgo fine sandy loam, 1 to 3 percent slopes (HGB); Hidalgo sandy clay loam (HO); Mercedes clay, 0 to 1 percent slopes (MEA); Racombes sandy clay loam (RA); Racombes soils and Urban land (RDX); Raymondville clay loam (RE); Raymondville clay loam, saline (RG); and Raymondville Urban land complex (RM) (Figure 2 1). All of the soils, except HGA, HGB, and HO, have severe limitations for septic tank absorption fields (U.S. Department of Agriculture [USDA] 1977). A brief description of each soil type within the planning area colonias, including septic tank absorption field limitations, is presented in Table 2 1. The existing WWTP is underlain by HO and RE soils. The existing WTP is underlain by HO and Hidalgo Urban land complex (HU) (USDA 1977).
(d) Prime and Unique Agricultural Land
Prime farmland soils, as defined by the U.S. Department of Agriculture (USDA), are soils that are best suited to producing food, feed, forage, fiber, and oilseed crops. Because of their quality, growing season, and moisture supply, prime farmland soils produce the highest yields with minimal inputs of energy and economic resources, and farming these soils results in the least damage to the environment. Prime farmland soils are subject to protection under the Farmlands Protection Policy Act (FPPA). The purpose of the FPPA is to minimize the extent to which Federal programs contribute to the unnecessary and irreversible conversion of prime farmland (7 United States Code [USC] 4201).
HGA, HGB, HO, RA, and RE soils are classified as prime farmland in Cameron County in their native state. BE, HU, MEA, RDX, RG, and RM soils are not classified as prime farmland soils in Cameron County (USDA 1995). An NRCS AD 1006 Form was completed for the proposed 150 foot buffer zone (5.2 acres) adjacent to the WWTP. The total score was 112 points, which is less than the 160 points needed to require further consideration for protection of farmland (7 CFR 658). Documentation of coordination with the NRCS is provided in Appendix A.
(2) Hydrological Elements
(a) Surface Water Bodies
The Rio Grande is approximately 2,000 miles long and forms the irregular international boundary between the United States and Mexico; it discharges directly into the Gulf of Mexico. The Rio Grande and the Arroyo Colorado Rivers are the major fluvial influences of south Texas. Santa Rosa is located within the Lower Rio Grande Valley area. The planning area colonias are located in the western portion of Cameron County, south of the North Floodway of the Arroyo Colorado. The hydrologic regimes of the Middle and Lower Rio Grande basins are highly regulated with the flow controlled by Amistad and Falcon Reservoirs. In the Lower Rio Grande Valley, irrigation water does not evaporate and return to the river, as would be the case for most irrigated areas. Instead, irrigation water passes through drainage systems into the Arroyo Colorado and the North Floodway, which function as huge drainage structures for the Lower Rio Grande Valley area. The North Floodway of the Arroyo Colorado is operated by the U.S. Section, International Boundary and Water Commission (USIBWC) and is used for flood control within the Lower Rio Grande Valley. In the vicinity of the planning area colonias, surface water features may be elevated and include the irrigation and drainage ditches of the Arroyo Colorado and the North Floodway system. The La Feria Main Channel conveys raw water from the Rio Grande to the Santa Rosa WTP. In addition, the Tiocano Lake is located in the vicinity of the southern project area colonias (SR 2, SR 1, SR 16, and SR 3). Tiocano Lake extends from FM 733 to the south for a considerable distance. Tiocano is an ephemeral lake, and in dry seasons contains little, if any, water. During wet seasons, the long, shallow depression acts as a large settling basin, collecting much of the upstream sediment load. The Tiocano Lake area may flood during hurricanes. In the past, the lake may have formed a dependable source of freshwater and a large area of wetlands throughout the year. Wetlands are not noticeably present at Tiocano Lake, a function of drainage and modern agricultural practices (TWDB 1994).
(b) Stream Segment
The proposed project lies within the Nueces Rio Grande Coastal Basin. The TNRCC has established Surface Water Quality Criteria (SWQC) for water bodies based on designated uses. The Arroyo Colorado system is the major drainage for Cameron, Hidalgo, and Willacy counties. The Arroyo consists of two major channels that drain a 2,344 square mile watershed (TNRCC 2001a). The Main Floodway of the Arroyo Colorado extends from the headwaters near the City of Mission in southwest Hidalgo County to Llano Grande Lake southwest of the City of Mercedes in southeast Hidalgo County, and joins the Arroyo near the Laguna Madre. The North Floodway splits from the Main Floodway of the Arroyo Colorado at the upper end of Llano Grande Lake. During flood conditions (flow greater than 1,400 cubic feet per second), approximately 60 percent of the flow in the Arroyo is diverted into the North Floodway. The North Floodway is a tributary to the Arroyo Colorado and has been designated by the TNRCC as stream segment 2200 (U.S. EPA 1997). The North Floodway has no designated use or applicable SWQC although potential water quality concerns are nitrate (1.0 mg/l), dissolved phosphorous (0.2 mg/l), total phosphorous (0.2 mg/l), sulfate, chloride and fecal coliform (400 colonies per 100 ml) based on data collected from two monitoring stations (TNRCC 1995). Monitoring stations used at least one time in the vicinity of the planning area are #13037 and #13036.
The Santa Rosa WWTP is permitted to discharge 0.39 million gallons per day (mgd) to the North Floodway and advanced treatment levels are required. A 20 mg/l BOD5, 20 mg/l TSS, and 2 mg/l Dissolved Oxygen effluent set is required under existing permit conditions.
(c) Water Rights
The Treaty of 1944 established the division of water between the United States and Mexico. This Treaty contained provisions related to the control of the Rio Grande between Fort Quitman, in west Texas, and the Gulf of Mexico. The Treaty described the allocation of water between the two countries and described the joint construction of three major storage reservoirs along the main stem of the Rio Grande for water supply, flood control, and power generation. The first reservoir constructed was Falcon Reservoir, which was completed in 1953. The Falcon Dam is located on the western edge of Starr County, Texas. The capacity of the Falcon Dam is 4,080,817 acre feet. The United States receives 58.6 percent of the capacity of Falcon Dam. The second reservoir, Amistad Reservoir, was completed in the late 1960’s and is located immediately west of Del Rio in Val Verde County. In addition to these two reservoirs, Anzalduas Dam, located on the main stem of the Rio Grande in Hidalgo County, provides a sump pump diversion into the two countries and regulates flow into the principal floodway system.
The rules and regulations applied by the TNRCC in administering water rights in the Lower Rio Grande basin, as well as international treaties and physical water delivery systems, play an important role in water supply evaluations. Under current rules, allocation of water in the LRGV is based on water rights recognized as a result of the 1971 Lower Rio Grande Water Case. The original lawsuit of this landmark case was filed in 1956. According to the judgment rendered in 1971, a storage reservoir in Falcon Reservoir equal to 60,000 acre feet was established to meet municipal and industrial demands, and a total of approximately 155,000 acre feet of water per year was allocated for municipal, industrial, and domestic uses. Irrigation water from the Rio Grande was allocated for 743,808.6 acres of agricultural use below Falcon Dam. Of this amount, 641,221 acres are assigned as Class A irrigation rights and the remainder is designated Class B rights. Whereas municipal and industrial users are granted the highest water priority, the result of the Valley Water Case was to establish a weighted priority system in the Lower Rio Grande Valley for allocating the remaining surface water supply to irrigation uses. The Texas Rio Grande Watermaster is responsible for allocating the amount of water that is distributed to Class A and Class B water holders and for supervising the use of all water in the Middle and Lower Rio Grande basins.
The primary raw water for the water supply system of the City of Santa Rosa is from the Rio Grande. The City of Santa Rosa obtains its water from La Feria Irrigation District Number 3 (LFID #3), which has adjudicated water rights to the Rio Grande. The City of Santa Rosa has a contract with LFID #3 to withdraw up to 900 acre feet per year from the La Feria Main Channel located west of the City of Santa Rosa. Santa Rosa will not need to obtain additional water rights to support the proposed water improvement project.
(d) Groundwater Resources, Aquifers, and Aquifer Recharge Zones
Potable water for the planning area colonias is obtained from the Rio Grande. The Lower Rio Grande aquifer or aquifer system consists of the Goliad Sand, the Lissie Formation, the Beaumont Clay, and Recent alluvial deposits. The Recent deposits, the Beaumont and Lissie Formations, compose the Chicot Aquifer, which yields moderate to large quantities of fresh to moderately saline water. On a regional scale, the complex vertical and horizontal interbedded nature of sand and gravel units cause the entire sequence to act as one aquifer. As a result, within a narrow band along the Rio Grande in Starr, Hidalgo, and Cameron counties, the entire water bearing sequence, extending from the surface to 400 to 500 feet below surface, is considered one aquifer unit known as the Lower Rio Grande Valley aquifer (Texas Department of Water Resources [TDWR] 1983).
The Lower Rio Grande Valley aquifer consists of clay, silt, sand, and gravel of fluvial or deltaic origin. Generally useable water is restricted to the upper 500 feet of the aquifer. No fresh water containing less than 3,000 milligrams per liter (mg/l) of dissolved solids is known to occur at depths greater than 300 feet in Cameron and Hildago counties. In the Santa Rosa area, the shallow water producing zone, within 75 feet of the ground surface, contains poor quality water. Recharge to this aquifer is from the percolation of precipitation and irrigation water and seepage from canals, drains, resacas, and the Rio Grande. Water normally moves from the Rio Grande to the aquifer, except when water levels drop (U.S. Department of Interior, Bureau of Reclamation 1995).
(3) Floodplains and Wetlands
Natural drainage patterns have been extensively altered in the Santa Rosa area. The USIBWC maintains a flood control project called the U.S. Floodway System. The system is comprised of reservoirs, dams, levees, floodways, and flow diversion structures. The purpose of this flood control project is to divert the tremendous discharge of the Rio Grande into a series of floodways in order to safely transport the waters of the Rio Grande to the Laguna Madre or the Gulf of Mexico (FEMA 1978). The Cameron County Drainage and Irrigation Districts maintains and operates the levee that runs north south through and west of SR 3.
Flood boundaries, identified by FEMA, are categorized into zones according to frequency and depth of inundation. The planning area colonias were investigated for 100 year floodplain encroachments. The information was obtained from FEMA’s Flood Insurance Rate Maps (FIRMs) for Cameron County, Texas. The majority of the planning area colonias are not located within the 100 year floodplain. Portions of SR 1, SR 2, SR 3, and SR 16 are located within the 100 year floodplain associated with Tiocano Lake (Figure 2 1). The existing WWTP and WTP are not located within the 100 year floodplain (FEMA 1981 and 1983).
The City of Santa Rosa and Cameron County are both participants in the National Flood Insurance Program (NFIP) and both have adopted flood damage prevention ordinances. The Cameron County Engineer is the Floodplain Administrator for Cameron County and the City Manager is the Floodplain Administrator for the City of Santa Rosa (see Appendix A).
Wetlands of varying size, as determined by the U.S. Fish and Wildlife Service’s (USFWS) National Wetlands Inventory (NWI), occur in the vicinity of the planning area colonias; however, there are no mapped wetland areas located within any of the planning area colonias, the existing WWTP, or the existing WTP. The closest mapped wetlands are associated with Tiocano Lake and are located south of SR 2 and east of SR 16 (USFWS 1983 and 1992) (Figure 2 1). The proposed project is not located within jurisdictional wetlands (see Appendix A).
(4) Climatic Elements
(a) Temperature, Precipitation, and Prevailing Winds
The climate in the Santa Rosa area is temperate tropical, with a mean temperature of 74 degrees Fahrenheit. Summers are hot and humid, with occasional heavy rains late in the season. Winters are temperate with occasional freezes. Mean precipitation is 25.4 inches, with peaks in September and secondary peaks in May and June. Relative humidity typically ranges from 88 percent during morning hours to 60 percent at noon (Natural Fibers Information Center 1987). Prevailing winds are to the south or southeast (TNRCC 1992). Figures 2 2 through 2 4 provide area wind rose data. The nearest monitoring stations to the City of Santa Rosa are located in Brownsville, Edinburg, and Mission, Texas. Brownsville is approximately 32 miles southeast, Edinburg is approximately 22 miles west, and Mission is approximately 32 miles west southwest of Santa Rosa. In the Brownsville area, the dominant wind direction is south to southeast approximately 60 percent of the time. In the Edinburg area, the dominant wind direction is south to southeast approximately 54 percent of the time. In the Mission area, the dominant wind direction is south to southeast approximately 57 percent of the time (TNRCC 2001b).
(b) Air Quality and National Ambient Air Quality Standards
The U.S. Environmental Protection Agency (EPA) has established primary and secondary standards known as the National Ambient Air Quality Standards (NAAQS) for six criteria pollutants: carbon monoxide, ozone, nitrogen dioxide, lead, particulate matter 10 micrometers or less in diameter, and sulfur dioxide. The closest air quality monitoring stations to Santa Rosa are located in Edinburg and Brownsville—one in Edinburg and one in Brownsville (TNRCC 2001c). Particulate matter is the primary air quality concern in the area and is produced by a variety of natural and man made sources. Particulates less than 10 microns in diameter (PM10) are of concern because they are more likely to be deposited in the lungs, where they could cause adverse health reactions. The NAAQS for PM10 is 150 micrograms per cubic meter (µg/m3) for a 24 hour sample, not to be exceeded on more than three days over a 3 year period and 50 µg/m3 for an annual arithmetic mean. Cameron County is in attainment or unclassifiable in respect to all NAAQSs (40 Code of Federal Regulations [CFR] 81.344).
(5) Biological Elements
(a) Major Plant and Animal Communities
(i) Plant Communities
An ecoregion map has been developed for the conterminous United States. Seven of twelve ecoregions established for Texas occur in the Rio Grande Valley. Three biotic provinces are established for the Rio Grande Valley and these are the Chihuahuan, the Balconian, and the Tamaulipan (TNRCC 1994). The Tamaulipan province includes southern Texas from the Balcones Fault Line to the Rio Grande. Brushlands, coastal marshes, and oak forest are found within the Tamaulipan brushland ecosystem. The unique biology of the area is due to the sub tropical climate and proximity to the Gulf of Mexico and the Rio Grande deltaic system (Jahrsdoerfer and Leslie 1988). Tamaulipan brushland is home to more than 600 vertebrate species and more than 1,100 species of plants. Cameron County is a separate biotic district, the Matamoran district, since it contains more luxuriant vegetation than the Tamaulipan (Blair 1950).
Plants characteristic of Tamaulipan brushland include honey mesquite (Prosopis glandulosa), species of Mimosa and Acacia, granjeno (Celtis pallida), guayacan (Guaiacum angustifolia), cenizo (Leucophyllum frutescens), whitebrush (Aloysia gratissima), prickly pear (Opuntia spp.), tasajillo (Opuntia leptocaulis), Condalia spp., and allthorn (Castela texana). Brush species whose densities decrease markedly in a northerly direction include: retama (Parkinsonia aculeata), Texas ebony (Pithecellobium flexicaule), anacuita (Cordia boissieri), and anacua (Ehretia anacua) (Blair 1950; Jahrsdoerfer and Leslie 1988). These Tamaulipan endemic species occur in some small remnant patches within the general area.
Through much of the Lower Rio Grande Valley, many areas previously in natural vegetation have been converted to agricultural uses such as row cropping, orchards, or pasture. More recently, population increases have resulted in additional conversion to urban land uses. The planning area is semi rural in nature and grain sorghum, corn, cotton, grain, cool season vegetables, citrus, and sugar cane are grown in area agricultural fields. The grasslands/brushlands and woodlands in the planning area are of limited extent. Common grasses in the planning area include buffelgrass (Cenchrus ciliaris), silver bluestem (Bothriochloa sacchariodes), and silky bluestem (Dichanthium sericeum). Silver bluestem is amid successional species on dry sandy soils, while buffelgrass and silky bluestem are introduced drought tolerant species that are now ubiquitous in grazingland throughout much of south Texas. Roosevelt weed (Baccharis neglecta) is a common invasive brush species in grazingland throughout the planning area. Honey mesquite, retama, spiny hackberry, lotebush and desert sumac (Rhus microphylla) are also found in brush patches. Black willow (Salix nigra), sugar hackberry (Celtis laevigata) and anacua, among other species, occur in riparian areas.
(ii) Animal Communities
The Tamaulipan biotic province includes a diverse assemblage of plants and animals. Approximately 700 vertebrate species have been identified. Given the diversity of the area, this description of animal communities in the region is general.
Sixty one species of mammals, 36 species of snakes, 19 species of lizards, 2 land turtles, 2 urodeles, 19 anurans (frogs and toads), 2 tortoises, and 3 urodeles (newts and salamanders) occur within the Tamaulipan province. There are more than 350 bird species that occur in the LRGV. Mammals include the jaguarundi (Felis yaguarundi), Coue’s rice rat (Oryzomys couesi aquaticas), the Mexican spiny pocket mouse (Liomys irroratus), and the Gulf Coast hog nosed skunk (Conepatus leuconotus texensis) (Blair 1950).
Snakes unique to the Tamaulipan brushland include the speckled racer (Drymobius margaritiferus), the northern cat eye snake (Leptodeira septentrionalis), the black striped snake (Coniophanes imperialis), and the Mexican hooknose snake (Ficimia streckeri). Lizard species within a few miles from the Rio Grande include the mesquite lizard (Sceloporus grammicus microlepidotus), the blue spiny lizard (Sceloporus cyanogenys), and the reticulate collared lizard (Crotaphytus reticulatus). One species of land turtle, the Texas tortoise (Gopherus berlandieri), occurs only in the Tamaulipan province (Blair 1950; Dixon 1987).
The two urodeles (newts and salamanders) that occur in the Matamoran district of the Tamaulipan province include the South Texas siren (Siren sp. 1) and the black spotted newt (Notophthalmus meridionalis). Anurans (toads and frogs) include the Mexican burrowing toad (Rhynophrynus dorsalis), the giant toad (Bufo marinus), the Mexican treefrog (Smilisca baudinii), and the white lipped frog (Leptodactylus fragilis) (Blair 1950; Dixon 1987).
Of the 350 or more species of birds known to occur in the Lower Rio Grande Valley, almost a third are threatened, endangered, occur on a watch list, or are of special management concern to the USFWS (Jahrsdoerfer and Leslie 1988). Many Neotropical resident species reach northern range extensions in the Lower Rio Grande Valley and many migrants pass through the area as well. Birds of freshwater marshes, lakes, ponds and rivers include Reddish Egret, White faced Ibis, Black billed Whistling Duck, White fronted Goose, and Olivaceous Cormorant. Threatened and endangered plant and animal species are discussed in Section II.A.5.b.
Planning Area Colonias
Because of the semi urban environment of the planning area colonias, wildlife anticipated is typical of that associated the City of Santa Rosa. Mammals such as rats, mice, ground squirrels, and various reptiles and amphibians may be present. Resident and migratory bird species, particularly passerine species, can be expected in the vicinity. Wildlife present at the USFWS Tiocano Lake and Thompson Road Lower Rio Grande Valley (LRGV) tracts include neotropical birds and waterfowl and Federally listed species, and rare and peripheral plants and wildlife that reach their northernmost range in south Texas.
The Texas Natural Heritage Program (TNHP) has identified several community types in extreme southern Texas that are considered rare or are threatened due to agricultural conversion and urban development pressure (TNHP 1992). Three closely related community types are the Texas Ebony – Anacua Series, the Texas Ebony – Snake eyes Series, and the Texas Palmetto Series. The Texas Ebony – Anacua Series is an evergreen subtropical forest occupying well drained but moist soils in the Lower Rio Grande Valley. Similarly, the Texas Ebony – Snake eyes Series is a subtropical evergreen shrub land or low forest occupying drier sites. The Texas Palmetto Series is also an evergreen subtropical woodland or forest limited to only a few sites along the lower Rio Grande. These shrub land/woodland community types were not observed within the planning area colonias.
(iii) Site Reconnaissance
A reconnaissance level (windshield) survey was performed by Turner Collie & Braden Inc. personnel in June 2001. A bull snake (Pituophis melanoleucus); domesticated farm animals, such as goats and chickens; Mourning Doves (Zenaida macroura); and Northern Mocking Birds (Mimus polyglottos), were noted during the site reconnaissance. Other common small mammals of the Tamaulipan province that may occur in the planning area include hispid pocket mouse (Perognathus hispidus), Mexican ground squirrel (Spermophilus mexicanus), Merriam’s pocket mouse (Perognathus merriami), white footed mouse (Peromyscus leucopus), northern grasshopper mouse (Onychomys leucogaster), hispid cotton rat (Sigmodon hispidus), southern plains woodrat (Neotoma micropus), and eastern cottontail (Sylvilagus floridana). Tropical species that have been known to spread northward include nine banded armadillo (Dasypus novemcinctus), northern pygmy mouse (Baiomys taylori), and fulvous harvest mouse (Reithrodontomys fluvescens). No species of concern were noted during the site reconnaissance.
(b) Threatened and Endangered Species
The USFWS has jurisdiction over species that are Federally listed as threatened or endangered. The Texas Parks and Wildlife Department (TPWD) provides protection for species listed by the State of Texas as threatened or endangered within the state. Sixteen Federally listed proposed, candidate, threatened or endangered species potentially occurring in Cameron County are listed in Table 2 2. Marine environments do not occur within the planning area colonias; therefore, the five listed sea turtles and the West Indian manatee are not considered to be potentially present. Likewise, the Piping Plover are primarily associated with coastal and barrier island environments that are not present within the planning area colonias. This species, along with the Arctic Peregrine Falcon, the Mountain Plover, and Bald Eagle may occur as migrants, and the Northern Aplomado Falcon may be present in the region, but none of these species are expected to use habitats within the planning area colonias. There are no known occurrences in the planning area colonias of star cactus, Texas ayenia, or South Texas ambrosia (USFWS 2001b and 2001c).
The dense thornscrub habitat prevalent in extreme south Texas represents the historic and current range of both the ocelot and jaguarundi. Ocelots tend to prefer the cover of dense thickets while the jaguarundi may tolerate interspersed cleared areas. The lack of vegetative cover, extensive clearing for historical ranching, agriculture, and citrus fruit trees in the planning area colonias, and the surrounding residential or urban environment are factors limiting the possibility of ocelot or jaguarundi occurring in the colonias (Appendix A).
As defined in the Endangered Species Act of 1973, as amended, critical habitat includes those specific areas within the current or historic geographical range of a species proposed for listing on which are found those physical or biological features 1) deemed essential to the conservation of the species and 2) that may require special management considerations or protection. For the threatened and endangered species listed in Table 2 2, no critical habitat has been designated within the state of Texas. The vegetative community occurring within the planning area colonias does not represent suitable habitat potentially used by the listed species.
Two species of mammals, the ocelot (Felis pardalis) and the jaguarundi (Felis yaguarondi) are on the Federal and state endangered species lists. These cats have specific habitat requirements, and do not reside in areas that do not meet these requirements. Both species require a thornscrub habitat with a dense understory and closed (75 to 95 percent) canopies. No such areas are present within the planning area colonias (Appendix A).
(c) State and National Parks, Natural Areas, and Refuges
Wildlife refuges and sanctuaries in the region include the Thompson Road tract and Lake Tiocano owned by the USFWS (USFWS 2001c). The USFWS has purchased two tracts of land as part of the Lower Rio Grande Valley National Wildlife Refuge acquisition project. The Thompson Road parcel is located approximately one mile south and east of SR 4 and the Lake Tiocano tract is south of SR 2 and SR 3 (Figure 2 1). These parcels of land owned by the USFWS are not contiguous and limited in extent but provide anchor wildlife areas, providing habitat for wildlife species migrating north and south. There are no state or national parks, preserves, or refuges located within the planning area colonias.
(6) Cultural Resources
Cultural resources defined here include historic sites, prehistoric sites, modern sacred or ceremonial sites and unmarked Indian graves. The age of sites found in Texas includes Paleo Indian, Archaic, Woodland, Plains Woodland, Mississippian, Plains Village, NeoAmerican, and Historic. As of 1995, there are over 10,000 National Register properties and over 51,000 recorded sites in Texas (U.S. Bureau of Land Management 1995). Within the Texas Gulf Coastal Plain, prehistoric occupations occur mainly as open camp sites, representing cultural occupations spanning the last 11,000 years, situated on either Holocene alluvial terraces adjacent to streams and rivers, or on the broad upland remnants of Pleistocene alluvial terraces (USACE 1999).
The number of listed National Register Sites and State Archeological Landmarks in Cameron County exceeds 175. Historic buildings comprise the majority of the National Register sites in the Texas Gulf Coastal Plain. Historic sites include forts, shipwrecks, plantations, lighthouses, depots, battlefields, battlefield cemeteries, towns, ranches, homesteads, churches and trading posts.
Prehistory in the Rio Grande delta area can be divided into four developmental stages—Paleoindian, Archaic, Late Prehistoric, and Historic. Very little work has been done on the prehistoric cultural resources of the Cameron County area. This work is primarily limited to surface collections by both professional and amateur archaeologists. Paleoindian sites may be present but deeply buried in the delta. Similarly, evidence of the ensuing Archaic may be deeply buried in the deltaic alluvium and is also scanty and rare in the Rio Grande delta (TWDB 1994). Evidence of Late Archaic sites may be associated with relict channel scars and along the shores of ephemeral lakes. Buried sites are encountered during construction of drainage ditches and irrigation canals.
Within the Rio Grande delta, two closely related Late Prehistoric stage complexes have been defined by (McNeish 1985). The Brownsville complex sites occur almost exclusively in Cameron County. Diagnostic artifacts include Cameron projectile points, conch shell fishhooks, shell plugs, columella gouges, conical pumice pipes, small shell beads, pierced conch shells, and pin like drills.
Prehistoric settlement patterns in the lower Rio Grande delta have received considerable attention as a result of proposed large scale drainage projects. A predictive model of site location for prehistoric settlements is summarized as follows (TWDB 1994):
The water related features that are identifiable and which are strongly associated with prehistoric site locations include eolian depressions in the sand dune field, relict distributary channel scars with eolian depressions on the deltaic plain, the levees adjacent to the channel scars…
The Texas Water Development Board performed an archeological survey of proposed wastewater and water utility improvements for the City of Santa Rosa in 1994 (Appendix A). TWDB archeologists reviewed project specific planning documents to establish potential impacts to environmental and cultural resources with investigations being conducted as necessary. The cultural resource investigations are conducted with the concurrence of the State Historic Preservation Officer (SHPO), consistent with Section 106 of the National Historic Preservation Act (NHPA), the Secretary of the Interior’s Guidelines, the regulations of the Advisory Council on Historic Preservation (36 CFR 800) and the requirements of the Texas Antiquities Code. These investigations were conducted pursuant to Section 106 of the NHPA (TWDB 1994).
No cultural resources were encountered during the pedestrian survey performed by the TWDB in 1994, although the margins of the Lake Tiocano area exhibit a high probability for archeological sites. The recommendation of the TWDB at the time of the initial investigation was that there was little chance that the project would affect cultural resources. The Texas Historical Commission (THC) concurred with the recommendations on April 11, 1994 (see Appendix A). The Texas Archaeological Sites Atlas does not indicate the presence of any known archaeological sites within or near the planning area colonias (TWDB 2002a), although this part of Cameron County has been identified as a high probability area for cultural resources by the TWDB (TWDB 1994 and 2000b). Through a recent verbal consultation between TWDB and THC, it has been determined that the 1994 concurrence is still valid since the project location and elements have not significantly changed since 1994 (TWDB 2002b).
(7) Economic Conditions
The following population and demographic information summarizes the characteristics of the most significant indices that are associated with the targeted areas. A requirement of the TWDB is to conduct a door to door survey to determine the level of service currently in place for water and wastewater, the economic conditions, and the number of residents in the planning area colonias. The door to door survey was conducted in early 2001. The survey included information on population, number of persons per household, and annual household income.
Population and Households
The existing population and projected population figures for the City of Santa Rosa and the planning area colonias are based on the 2000 Census, TWDB’s 2002 State Water Plan, and door to door survey results. The 2000 population for the City of Santa Rosa was 3,071, which represents a 21 percent increase from 1990 (U.S Census Bureau 1990 and 2000). The City is expected to have a population of approximately 4,104 residents in the year 2020 (TWDB 2000a). The racial/ethnic distribution for Santa Rosa is approximately 96 percent Hispanic or Latino; 3 percent white; and one percent other (U.S Census Bureau 2000).
There are approximately 291 existing dwellings located within the 15 planning area colonias, with an estimated population of 1,173 persons. The proposed water and wastewater improvements are designed to provide adequate services to in city and colonia residents to the design year 2020. The proposed water and wastewater improvements would serve an estimated total of 1,568 colonia residents (392 households) and 4,104 in city residents, for a total of 5,672 persons in 2020.
The total number of dwellings in the individual colonias varied from minimum of 3 dwellings to a maximum of 41 dwellings. The average household size for each of the planning area colonias varied from a minimum of 2.6 persons per household to a maximum of 5.66 persons per household, for an overall average of 4.0 persons per household (City of Santa Rosa 2001). Table 2 3 presents the number of existing dwellings and the average household size for the planning area colonias.
The median household income in Santa Rosa was $15,500 in 1990. Based on current surveys, the adjusted average household income for Santa Rosa in 2000 is estimated to be $22,123. Approximately 47 percent of the population of Santa Rosa live below the national poverty level. The average annual household income in the planning area colonias varies from a minimum of $14,333 to a maximum of $45,250. The weighted average annual household income was $22,123, based on the responses received during the survey. The average annual per capita income for the planning area colonias varies from a minimum of $3,022 to a maximum of $12,929. The overall average annual per capita income is $5,511, based on the responses received during the survey. This income level is well below the EDAP income per capita income ceiling of $17,981; therefore, all of the planning area colonias are EDAP eligible (City of Santa Rosa 2001). Table 2 4 presents the average annual household income, average household size, and average annual per capita income for each of the planning area colonias.
(8) Land Use
The major land use in Cameron County is mixed with agriculture uses dominating (54 percent), followed by rangeland (27 percent). Land use for recreational activities is 10 percent including land used for fishing, hunting, water sports, and other related year round tourist activities. Numerous historic and wildlife areas also occur in the county. Land use within the planning area is primarily of single family residential, agricultural, and undeveloped. The area is accessed by FM 506 and SH 107 and the Southern Pacific railroad trends through the planning area in a northerly direction. Residential areas are mainly located on the outskirts of Santa Rosa, along area roadways and highways. There is a large antenna facility near Sasha Road and FM 506 near the La Feria Terrace Subdivision. The Central Power & Light (CPL) Santa Rosa substation is at FM 506 near Torbido Road. The area is crisscrossed with a network of drainage and irrigation ditches that support local farming operations; a major elevated canal is accessed along Pomelo Road. The La Feria Main Channel trends north south between FM 506 and Rabb Road west of Santa Rosa. Numerous underground utilities are present such as General Telephone (GTE) and Southwestern Bell underground telephone cables and natural gas pipelines (El Paso Field Services). Commercial establishments in the planning area include Cruz Flower Shop, Frank’s Paint and Body Shop, and La Feria Wrecker Service. At least two churches in the area are Puerto Del Cielo and Frontier Baptist Mission. A cemetery noted during the site inspection is the La Capilla Cemetery along Tio Cano Road. Livestock such as goats and chickens are present at Lievens Farms and at the ranch owned by Aaron Agado. The Refugio Del Guardarraya is part of the Great Texas Coastal Birding Trail and is also the Lake Tiocano LRGV tract owned by the USFWS. This refuge is immediately south of the planning area on FM 733.
(9) Other Programs
This section discusses other programs or projects that are currently under construction or are planned that may be impacted or could impact the proposed project. The USFWS has embarked on a high priority program to acquire lands generally between the USIBWC levee and the Rio Grande from Falcon Dam to the Gulf of Mexico to establish a wildlife travel corridor. In the vicinity of the project, several tracts along Thompson Road and near Lake Tiocano have been acquired by the USFWS. At this time, this program should not impact or be impacted by the proposed project. The TNRCC has established water quality standards from criteria established to protect designated uses of state surface water bodies. The proposed project will positively benefit the surface water quality of the area and support the TNRCC designated use criteria. In the event that cultural resources are encountered during construction, work would cease, deposits would be protected from further disturbance and the THC would be contacted immediately. Although identifying cultural resources during construction may result in project schedule adjustment or realignment, no impacts to area cultural or archeological resources would be expected. The U.S. Bureau of Reclamation has implemented a project for the rehabilitation of diversion, distribution, and drainage systems of the La Feria and Mercedes Division to permit more efficient operation and maintenance of works. Rehabilitation was also performed to reduce seepage losses from canals and laterals and to provide drainage relief from a design storm that would produce 2.6 inches of runoff. The reduction in the distribution system loss and waste resulting from rehabilitation has resulted in a positive economic benefit. The water conserved is available to minimize water shortages. This rehabilitation program will indirectly positively benefit the proposed project.
(B) FUTURE ENVIRONMENT WITHOUT THE PROPOSED PROJECT
The low income, minority residents of the colonias within the planning area colonias suffer from the lack of adequate water and wastewater facilities. Without this project the lack of such essential and significant infrastructure elements would be exacerbated. These aspects are discussed below.
Without the proposed wastewater improvement project, sanitary conditions would remain substandard. Poorly designed, constructed, and maintained septic systems would continue to overflow and outflow, exacerbating surface water contamination and leading to possible groundwater contamination. Developmental pressures would continue leading to an increase of loading on existing systems. Area soils are not suitable for septic tank systems and would contribute to the lack of effective wastewater treatment options in the area.
Existing on site wastewater treatment systems (i.e., septic tanks) do not operate properly and will continue to malfunction. Surface water and groundwater would continue to become polluted by wastewater. Water quality of the Rio Grande would potentially degrade as a result of no action since inadequate wastewater treatment to support existing and projected populations would result in untreated wastes being directly or indirectly discharged to the river. There would be an increase in the potential for surface water and groundwater contamination from untreated or poorly treated sewage discharged at the surface. This could affect and potentially degrade the water quality of the area surface water features including the North Floodway, Lake Tiocano, and the La Feria Main Channel.
Floodplains and Wetlands
In the event of periodic or seasonal flooding, contamination from untreated or sub standard sanitary waste may be carried and deposited by floodwaters throughout the City of Santa Rosa.
Plants and animals in the planning area colonias and the surrounding areas may be negatively impacted due to the seepage into surface water and groundwater from gray water and inefficient or overflowing septic systems.
Failure to implement the proposed project would result in the erosion of land values and the quality of life for all residents of Santa Rosa. The health and safety of the colonia residents and people of the City of Santa Rosa would be negatively impacted through lack of adequate wastewater treatment service. Colonia residents, both adults and children, would experience both short and long term health impact that would accumulate and affect successive generations. Potential communicable diseases that may affect these populations include tuberculosis and gastro intestinal diseases. The long range development goals of the City of Santa Rosa would not be met. There would be a lack of sufficient infrastructure to support the projected land development growth associated with the implementation of the NAFTA. As the colonia areas continue to grow and expand, the lack of an adequate water and wastewater system will create detrimental impacts both on the infrastructure and on the economic quality of life. Human suffering due to the impacted health of colonia residents can be related to the discharge of inadequately treated wastewater to the land surface. These areas are likely to continue to expand without the chance of developing beyond substandard or minimum standard housing developments.
If this project is not implemented the regional development of the Santa Rosa area and Cameron County would continue to be faced with the dilemma of “negative urbanization” through the growth and development of colonias that lack basic human infrastructure requirements. The proposed project will address the problem of water and wastewater improvements in the area’s substandard housing developments. The absence of such programs will have a negative impact on the future characteristics of urban and rural development in the area. Providing the necessary infrastructure to colonias now will help the region develop and adopt a more sophisticated approach to the future residential, commercial, industrial, and agricultural development.