North Llano

Watershed Hydrology

The North Llano Watershed is located in the Edwards Plateau region of Texas and covers an area of approximately 1,413 square miles. The watershed is characterized by a semi-arid climate with average annual precipitation of 23 inches, most of which occurs in the summer months. The hydrology of the watershed is largely influenced by the underlying geology, which consists of limestone and sandstone formations that allow for rapid infiltration and recharge of the aquifer. Snowpack is not a significant factor in the North Llano Watershed due to its location in a warm, arid region. Surface water resources in the watershed are limited, with the main water bodies being the North and South Llano Rivers. These rivers support a variety of fish and wildlife species and are popular recreational destinations for fishing, kayaking, and swimming. Reservoirs in the watershed are primarily used for municipal water supply and irrigation. The main constituents in the reservoirs are dissolved minerals, including calcium, magnesium, and bicarbonate. In recent years, the North Llano Watershed has experienced a trend of increasing temperatures and decreasing precipitation, which has led to drought conditions and increased pressure on water resources. This has led to efforts to improve water conservation and management practices in the watershed.


Surface Flows

North Llano Watershed

Snowpack Depths

North Llano Watershed

Dams & Reservoirs

North Llano Watershed

Groundwater Levels

North Llano Watershed

North Llano Rivers

Rivers of the Watershed