Potable Water System Interconnect

JR Engineering prepared a design for a connection between two potable water systems, owned and operated by two different Districts at two different pressure zones.  The objective was to be able to provide water between the Districts in the event of an outage, with the potential for metered flow to go in either direction.

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The interconnect piping connected a Dominion W&SD 18-inch water main on Chatfield Lake Road to a Centennial W&SD 12-inch main.  Approximately 110 linear feet of potable water main was required outside the Chatfield Lake Road right-of-way to connect the two independent potable water systems.

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The interconnect piping was placed in a large, custom-sized concrete utility vault, and manual operation of the valves is intended to allow for flows in either direction.  Meters were provided on both lines inside the vault to measure the flows provided to either District by the other.  The Dominion system operates at a higher pressure than the Centennial zone it connects to, so a PRV was included in the design.  Sampling ports were provided inside the vault for the Districts to obtain samples for water quality testing.

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​Pressure Management, Metering & Vault Design

The utility vault also involved the relocation of a fire hydrant and the addition of an air vac valve to the system.  Approximately 100 linear feet of existing concrete detached sidewalk was removed, realigned, and replaced to accommodate the construction of the vault.

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​Easements & Permitting

JR Engineering prepared utility easements for the vault, which was located in a Metro District tract.  Centennial W&SD prepared easement agreements.​ The vault design also required a Douglas County Small Utility GESC Report and Permit.