Siena Reservoir Pump Station and Pipeline

News & Updates...............

A Request for Qualifications/Proposals was advertised in late January for a Construction Manager/General Contractor (CM/GC) to add to the project team. Moltz Construction was selected.  The CM/GC will assist with reviewing constructability, analyzing potential cost savings and scheduling of the project.  In addition, the CM/GC and staff will develop a project construction cost and overall schedule which will be presented to Council for review and approval before construction begins.  The design is currently 75% complete and anticipated to be complete by the end of the year depending on the status of the SDP.

Since the size of the pump station building will exceed ten percent from the original Site Development Plan (SDP), the project will require a SDP amendment. The team met with Planning to begin the process and a neighborhood meeting was held on Wednesday, May 4, 2022.  The first formal submittal was completed and is currently out for referrals by Planning.  The design team has begun the SDP process which is expected to take 6 to 9 months to complete.

The Siena Reservoir Pump Station and pipeline project is for a station to pump raw water from Siena Reservoir to Glaser Reservoir and the Water Treatment Facility to assist in meeting the water demands for Broomfield residents. Council approved a design consulting agreement with Muller Engineering for design and construction documents on May 11, 2021.


The City and County of Broomfield (Broomfield) at the November 10, 2020 Council Meeting retained Muller Engineering Company to complete a Preliminary Design Report for the design of a pump station and associated pipeline from Siena Reservoir (Siena) to the Broomfield Water Treatment Facility (WTF). Siena is located northeast of the intersection of Lowell Boulevard and Sheridan Parkway and south of the Northwest Parkway in Broomfield with a normal storage capacity of 450 acre-feet.  The WTF is located at 4395 west 144th Avenue, Broomfield, Colorado.  

A pumping station at Siena and a pipeline will deliver water to the WTF.  The facilities would assist in meeting peak summer demands for potable water.  The anticipated capacity of the facility would be 10 to 15 cubic feet per second (CFS) and 14,200 feet of pipeline expected to be 20 to 30 inches in diameter.

Broomfield has two major water supply sources: treated water purchased from Denver Water, and raw water from both the Colorado-Big Thompson (C-BT) and Windy Gap Projects. One of the City Council’s ongoing priorities is water resource acquisition and development. This includes efforts to continue moving the Windy Gap Firming Project (WGFP) forward, acquiring water rights, and constructing new capital facilities. 

Broomfield’s Water Treatment Facility (WTF), located at 4395 West 144th Avenue, treats the raw water supplies from the C-BT and Windy Gap Projects. A CIP project to expand the WTF by 6 MGD to its current 26 MGD was completed fall 2020.  

To provide a sufficient water supply to the Water Treatment Plant (WTP) during summer when water demands are highest, additional raw water storage is needed in Broomfield. Siena Reservoir is an asset of the Water Fund and is filled by a connection to the Carter Lake pipeline. Stored water cannot be drained except through the spillway and a new pump station and pipeline is required to deliver the water from Siena Reservoir to Glasser Reservoir or directly to the WTP. The improvements will provide seasonal summer storage for the next 10 to 15 years years until the Broomfield Reservoir is needed. A map showing the location of Siena Reservoir and proposed pipeline alignment is shown here:

Siena Oct. 2022

simulations 6 30 22_Page_1

Siena Fence Oct. 2022

simulations 6 30 22_Page_3

simulations 6 30 22_Page_4