Streetscape Environmentalism: Floods, Social Justice, and Political Power in San Antonio, 1921–1974

Abstract

Streetscape Environmentalism: Floods, Social Justice, and Political Power in San Antonio, 1921–1974 Char Miller (bio) Click for larger view View full resolution Map of prominent water features of San Antonio’s west side. Map by Charles D. Grear. [End Page 158] You can locate Zarzamora Creek on the map: type in its coordinates on Google Earth—N 29°31, W 98°34—and you will have pinpointed its cartographical location. But that digital representation will tell you little about its environmental significance or its cultural meaning to the city of San Antonio. Often bone-dry, the Zarzamora is an eight-mile dusty channel that falls away from the Hill Country to the northwest of the urban core. The creek first twists and turns in a south-westerly direction, breaks south and east before flowing into a retention pond known as Elmendorf Lake, merging there with Apache Creek. Their combined stream flow then presses into San Pedro Creek a mile or so above its confluence with the San Antonio River. The Zarzamora is thus a small part of the San Antonio’s 4,180 square-mile drainage system. Perhaps the Zarzamora’s frequent dryness and small size are why the Spanish, who gave the creek its name, neglected to demarcate its presence in their eighteenth-century maps of this sprawling watershed, which made arable the river valley where they sited five religious missions, built a civilian community and a presidio, and irrigated innumerable farms and [End Page 159] ranches. For these colonists, like most modern-day San Antonians, Zarzamora Creek left an almost-invisible mark on the South Texas landscape. But the Zarzamora has a habit of becoming quite noticeable when it rains. Then, what appears unimportant and practically indecipherable becomes overwhelming in significance and force. To account for this startling transformation, start with the confluence of meteorology and topography. San Antonio lies just east of the 100th meridian, long identified as the break point between the humid East and arid West. But this meteorological boundary is not as fixed as the meridian appears on a map, and depending on whether the Pacific Ocean is in an El Niño or La Niña cycle, San Antonio oscillates between deluge and drought. The amount of rain that can fall is startling: the prevailing southeasterly breezes pull supersaturated air up from the Gulf of Mexico that rises as it reaches San Antonio and the Hill Country. Should this uplift collide with a wall of high-pressure air or a cold front pushing down from the north, the resultant storms can produce lightning and earthshaking thunder, and can quickly drench and race across parched ground. In late June and early July 2002, for instance, upwards of thirty-five inches fell in seven days, and the two major rivers that cut through the city, the San Antonio and the Medina, registered record heights; tragically, twelve people lost their lives. On October 17–18, 1998, the same scenario had occurred after a cold front slammed into the region’s high humidity, which then was supercharged by “a plume of moist mid- and high-level air . . . streaming across the area from Hurricane Madeline off the west coast of Mexico.” More than twenty inches of rain fell in twenty-four hours, killing eleven.1 The problem was not solely how much precipitation slanted down as where and how it landed. The Hill Country, and the larger Edwards Plateau of which it is a part, serve as an elevated catchment basin; as rainwater hits and cascades down its slopes, it is funneled into channels that over the millennia have been carved into the limestone terrain. From Austin to San Antonio, a series of rivulets, creeks, and streams carry these turbulent floodwaters to the flatlands, where they power into the Little Colorado or San Marcos, Guadalupe or San Antonio Rivers, which carry the churning flow south and east into the Gulf of Mexico. This complex combination of weather patterns, geological structures, and riparian systems, along with the killer surges they regularly produce, has led the National Weather Service to dub south-central Texas “Flash-Flood Alley.”2 Zarzamora Creek has contributed its share to that...