Representative Projects
Hydrologic Studies ~ Water Rights Engineering ~ Water Supply Planning ~ Design, Ops & Maintenance
Hydrologic Studies
Client: City of Lincoln, Nebraska
The City of Lincoln's principal source of water supply is a well field located in the Platte River alluvial aquifer near Ashland, Nebraska. TZA staff members conducted a computer modeling study to refine the City's understanding of the interactions between the alluvial aquifer and the Platte River. The USGS modular three-dimensional finite difference ground water flow model was used to expand and update an earlier model study. The model encompasses a 28 square mile area, and simulates various aspects of the hydrologic system, such as wells, rivers, precipitation, and boundary conditions.
The model results were used to optimize the configuration of potential new well fields on the east bank of the river and on an island in the Platte River; to define the impact of these new well fields on the yields and pumping levels of the existing wells; to determine the maximum reliable yield obtainable from the combined well fields; to evaluate alternative modes of operation; and to develop well design criteria. The model developed during this project now serves as an important tool in planning for the City's water supply needs.
Clients: District 67 Water Users Association and Fort Lyon Canal Company, Southeastern Colorado
TZA performed an evaluation of the effects of past administration of the Arkansas River Compact upon water rights both upstream and downstream of John Martin Reservoir. This study involved extensive analysis of pertinent water rights, the Arkansas River Compact, historical diversion and water utilization practices, and historic streamflow records. TZA also provided technical assistance to District 67 and the Fort Lyon Canal Company in evaluating the potential effects of amendments to the Operating Principles for Trinidad Reservoir proposed by the Purgatoire River Water Conservancy District and the Bureau of Reclamation. Technical issues raised by the proposed amendments include potential impacts upon inflows into John Martin Reservoir and related implications upon the administration of the Arkansas River Compact.
Client: Northern Colorado Water Conservancy District
TZA performed hydrologic modeling to support a Biological Assessment that investigated the potential impacts of diversions from a proposed new municipal water delivery pipeline on the Cache la Poudre River upon threatened and endangered species in the Platte River Basin. The data‑base maintained by the Colorado Division of Water Resources was accessed to obtain historic daily diversion, storage, and trans-basin import records for all major structures in the basin. Historic stream gauge flow records were obtained from U.S.G.S. data. A water balance accounting model was developed and used to compute historic point flows below each major diversion structure on the Cache la Poudre River on a daily basis. These point flow values were used to evaluate the quantity of unappropriated water and exchange potential. The proposed pipeline diversions were modeled to determine the resulting streamflows at various key locations on the river.
