When the reservoir begins to fill to its new, increased capacity in 2026, the project will have spanned nearly a quarter century from the start of environmental study and permitting to the end of construction. The total investment needed to finish the project, or the estimate at completion (EAC), is currently anticipated at about $464 million (in 2025 dollars). This value includes all past expenditures ($25 million as of 2017) and predicts future expenditures; accounting for expected changes due to variables like labor and commodities costs and economic inflation. The EAC will continue to be refined as design is finalized, recommendations from the constructability review process are incorporated, risk mitigation is fully implemented, etc.
As a public agency, Denver Water is entirely funded through rates, new tap fees and the sale of hydropower. No tax dollars will be directed towards Denver Water or to the Gross River Expansion Project. The City of Arvada is a partner in the project and will contribute a portion of the funding in exchange for additional water from Denver Water.