The Lower Pecos watershed, also known as HUC 13070008, covers an area of approximately 19,525 square miles in southwest Texas. The watershed is largely dependent on groundwater and includes the Pecos River and its tributaries. The region has a hot and arid climate with limited precipitation, which leads to low annual streamflow and limited surface water availability. The watershed contains several reservoirs, including Amistad Reservoir, which is a significant source of water for agriculture, recreation, and municipal use in the region. The area experiences significant fluctuations in temperature, with average highs ranging from the mid-70s in the winter to the mid-90s in the summer. In recent years, the region has experienced a trend of decreasing snowpack and increasing drought conditions, leading to concerns about water availability in the future.