Thornton Northern Water Supply Project Litigation City of Thornton, Colorado
The City of Thornton began acquiring farms and water rights in Northern Colorado
in 1985 to meet future water demands. Deere & Ault staff conducted several
engineering studies to assist the City in transferring the water rights to municipal
use.
Deere & Ault staff conducted historic consumptive use analyses for 103 farms
acquired by the City of Thornton, provided groundwater modeling, conducted Poudre
River basin modeling, provided raw water system planning, and provided litigation
support for water rights applications as part of Thornton's Northern Water Supply
Project.
The engineering studies included a historic consumptive use analysis and return flow
analysis for irrigation water applied to each of the 103 farms acquired by the City
of Thornton.
Deere & Ault staff conducted a phased study of groundwater and surface water flow
regimes and interactions in the Lower Cache la Poudre River basin. The study consisted
of groundwater modeling, including analysis of existing and projected water quality impacts.
Deere & Ault staff installed and designed monitoring wells, conducted aquifer tests,
compiled surface and subsurface geologic data, constructed isopach structure contour and
potentiometric surface maps, and implemented a detailed data base management system.
Deere & Ault staff conducted a project completion study to determine the most efficient
way to deliver water from the Poudre basin to Thornton. The Project Completion Study
involved:
determining project yields;
assessing present and future water demands;
determining project components;
estimating project costs; and
developing an augmentation plan.
Deere & Ault staff provided litigation support, including extensive expert witness
testimony during the 55-day trial. A decree was awarded to Thornton that will provide
an average annual raw water supply of 56,800 acre-feet.
