Surface Water Hydrology
Rainfall / Runoff Relationships
Mine Site In Southern Colorado:
A rainfall-runoff relationship had to be developed to assess the rainfall water captured in a tailings facility that would need to be augmented, i.e. the percentage of rainfall that would runoff and become surface flow. LWS personnel conducted test drilling and evaluated surficial soil conditions to develop a runoff curve number to be used in the assessment of augmented both flows being captured within the tailings facility.
Industrial Site In The Central Valley, California:
The flow characteristics of an ephemeral stream in the Central Valley, California need to be understood for contaminant transport modeling. A regional watershed analysis of the rainfall-runoff relationship had to be developed to understand the frequency, duration, and intensity of surface water flows that could transport contaminants in the surface channel. Local climatic and soil data, as well as stream channel properties were used to estimate runoff from various store events. This modeling analysis led to identification of extensive contaminant transport through the surface channel which ultimately recharged to the ground water system and contaminated municipal production wells. This information led directly towards settlement of a civil lawsuit related to the ground water contamination of the municipal production wells.
Rueter-Hess Reservoir, Parker, Colorado:
The water supply available to the 72,000 acre-foot Rueter-Hess Reservoir is from two principal sources, Cherry Creek and Newlin Gulch (where the Frank Jaeger Dam is located). While flow records were readily available for Cherry Creek, LWS personnel had to develop synthesized flow records for Newlin Gulch using a rainfall-runoff relationship. It was important to understand the additional flows that would move by gravity flow into the reservoir, both to understand additional water supplies that would be available and to assess potential releases that would have to be made when the inflows were out-of-priority.
Reservoir Sites In Southern Colorado:
LWS has assessed the potential yields related to two relatively junior reservoirs on the Huerfano and Cucharas Rivers related to their ongoing use as irrigation water supplies versus a change of use to allow the water to be used for multiple purposes. Gaged flow data are not available near the reservoirs, therefore, LWS needed to synthesize flow data from existing gaging stations and a rainfall-runoff relationship. These data were then used in the reservoir operational model to assess the reliability of these rights under the Colorado Doctrine of Prior Appropriation.