To: Honorable Mayor and Members of Town Council
From: Mark Marlowe, PE, Director of Castle Rock Water
Matt Benak, PE, Water Resources Program Manager
Angie Brown, Water Resources Program Analyst
Title
Resolution Approving the Agreement for Purchase and Sale of Western Pipeline and Ridgegate Pipeline Capacity
Body
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Executive Summary
The purpose of this memorandum is to request Council approval of a resolution (see Attachment A) approving the agreement for purchase and sale of Binney Connection, Western Pipeline and Ridgegate Pipeline capacity. Castle Rock Water staff recommends that the Town purchase additional WISE Infrastructure capacity in order to take full advantage of the Town’s northern (Box Elder) and WISE supplies (including the existing subscription and soon-to-be-purchased Douglas County option). The Town’s current capacity subscription in the WISE infrastructure is not sufficient to convey these supplies under all potential peak operating scenarios due to several bottlenecks from the planned Binney connection through the Ridgegate line. Staff recommends purchasing capacity in these bottlenecks which are currently for sale by Denver Southeast Suburban Water & Sanitation District d/b/a Pinery Water & Sanitation District (Pinery) per the terms of the attached agreement (Exhibit 1). The sale price is $2,287,966.50 which is essentially what Pinery paid for this capacity.
History of Past Town Council, Boards & Commissions, or Other Discussions
On March 27, 2019, the Castle Rock Water Commission unanimously voted to recommend Council approval of this agreement.
Discussion
When the WISE Authority formed in 2013, Castle Rock Water originally subscribed to 1,000 acre-feet (AF) of annual WISE flows and subsequently purchased capacity in the Binney Connection and Western and Ridgegate pipelines, proportionate to Castle Rock Water’s pro-rata water subscription (4.16, 5.26, and 3 million gallons per day (MGD), respectively). An annual subscription of 1,000 AF averages to a daily flow of 1.3 MGD with peak flows of potentially 3.1 MGD. Castle Rock Water’s original capacity subscription was sufficient, or nearly sufficient to meet even maximum WISE flows.
However, since 2013, Castle Rock Water has secured additional water rights northeast of the Denver Metro area which staff anticipates bringing to the Town through the WISE infrastructure at a rate of 3 MGD as a base flow beginning in the mid- to late 2020’s. Furthermore, Castle Rock Water is in the process of purchasing an additional 1,000 AF of WISE water through the Douglas County option. Including the original WISE subscription, the Douglas County option, and northern supplies, the average daily flow can now be anticipated at a rate of 4.8 MGD while maximum flows can be expected at 7.4 MGD. This means that to meet average flows, Castle Rock Water will need to secure an additional 0.64 MGD in the Binney Connection and an additional 1.8 MGD in the Ridgegate line. To meet potential maximum flows, Castle Rock Water may want to purchase an additional 3.24 MGD in the Binney connection, an additional 2.14 MGD in the Western line, and an additional 4.4 MGD in the Ridgegate line to provide maximum operational flexibility.
Attachment B (average expected flows) and Attachment C (maximum expected flows) outline where Castle Rock Water can expect to experience bottlenecks for average and potential maximum flows. An overview of system infrastructure capacity and area bottlenecks is included as Attachment D.
Similar to Castle Rock Water, Pinery is a member of both the South Metro Water Supply Authority (SMWSA) and the South Metro WISE Authority (SMWA), a political subdivision formed in 2012 to execute and administer the WISE Project. Pinery originally subscribed to 500 AF annually of WISE water but excess capacity in WISE infrastructure, thereby freeing up capacity for sale in the WISE system.
Although Castle Rock Water staff recommends finding additional capacity to ensure full operational flexibility, by purchasing Pinery’s available capacity in the Binney Connection, Western Pipeline, and the Ridgegate Pipeline, the Town ensures much more operational flexibility to maximize the Town’s renewable and reusable water from the WISE and Box Elder projects.
Budget Impact
If Council approves the agreement, Castle Rock Water will purchase available capacity from Pinery for $2,287,966.50. Funding for this purchase will come from the WISE Infrastructure account (211-4375-443.77-72) which currently has a balance of $6.17 million.
Staff Recommendation
Staff is recommending approval of the Agreement for Purchase and Sale of Western Pipeline and Ridgegate Pipeline Capacity which will enable the Town to purchase Pinery’s capacity of 0.58 MGD in the Binney connection, 1.07 MGD in the Western Pipeline, and 1.00 MGD in the Ridgegate Pipeline.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Attachments
Attachment A: Resolution
Exhibit 1: Agreement
Attachment B: Capacity map for average flows
Attachment C: Capacity map for maximum flows
Attachment D: Overview of Bottlenecks