The Upper Black Squirrel Creek drainage basin is located in the southern part of the structural Denver Basin. This basin encompasses an area of approximately 350 square miles and is entirely within east-central El Paso County, Colorado. The northern portion of Black Squirrel Creek and its associated tributaries, of which Brackett and Big Springs Creek are the only two commonly named, form a drainage basin known as Upper Black Squirrel Creek basin. All the streams in the basin are ephemeral, have dry sandy streambeds, and flow only in direct response to thunderstorms, spring snowmelt, or prolonged periods of rainfall. Consequently, these streams are not a reliable water source. Water supply over much of the basin comes from the alluvial aquifer and the underlying Denver Basin bedrock aquifers. As surface water is scarce and groundwater has been the dominant water source since the late 1800s, the Colorado Ground Water Commission established the Upper Black Squirrel Creek Designated Ground Water Basin in May 1968.
The objective of this project is to evaluate and refine the existing knowledge of the hydrogeology of the alluvial aquifer system in the Upper Black Squirrel Creek basin for the purposes of assessing the potential for aquifer recharge and storage implementation. Geographic, geologic, hydrologic and water quality data were collected and analyzed to evaluate the recharge potential, storage capacity, and ambient water quality in the study area. The study area encompasses the entire Upper Black Squirrel Creek drainage basin and coincides with the designated ground water basin boundary. The report includes a discussion of the geology of the basin; groundwater aquifers, withdrawals, recharge and levels; alluvial aquifer properties; alluvial storage capacity; and land use/ownership and available infrastructure. Digital PDF download. OF-08-04D