Douglas County commissioners voted Jan. 13 to approve a first amendment to an intergovernmental agreement (IGA) with the city of Castle Pines to increase the county’s contribution for design work on the Happy Canyon Road/I‑25 interchange project.

Art Griffith, the county’s transportation CIP manager, told the board the project (Douglas County project CI2012‑011) has been under county work since 2012. He said the county and partners previously secured roughly $2,600,000 through a transportation improvement program award for design and environmental studies, and the county had earlier contributed $1,100,000 toward a $4.4 million design package.

The amendment before the board would add $500,000 to the county’s contribution to advance items such as final design, independent cost estimating and tasks related to devolution of a bridge to local agencies. Griffith said some funding for construction (about $20,000,000) is already in the county’s approved budget and that the $500,000 comes from savings the board shifted into the project; he said bids have not yet been solicited and the project requires CDOT approvals for certain elements.

The county described its procurement approach as using a construction manager/general contractor (CM/GC) for early contractor involvement to identify savings during design; an independent cost estimator will review contractor costs. Castle Pines City Manager Michael Petty said his city hopes construction will start this year with completion in 2027 or, at the latest, early 2028.

Commissioner George Teal moved to approve the amendment; the motion was seconded and passed unanimously. Commissioners said the interchange is a key piece of a larger transportation solution for the I‑25 corridor between Castle Rock and Lone Tree and emphasized that no new taxes or fees were being raised to fund the amendment.

Next steps described by staff include advancing final design packages (northern bridge first) and obtaining necessary CDOT approvals before advertising construction bids.