Commercial, Office, and Industrial Projects

Delta Coves Utility Project

Diablo Water District & City of Oakley, 2014 - 2016

Loewke Planning was retained by the Diablo Water District to assist in the preparation of an MND, and later an Addendum, for the Delta Coves Utility Project in order to serve the future residents of Delta Coves with potable water for domestic and fire suppression purposes and natural gas from the PG&E gas pipeline. Additionally the new trunk line will provide water for new fire hydrants to be installed along Bethel Island Road, between the Bethel Island Bridge and Sandy Lane. The previous Delta Coves EIR provided analysis for up to 498 single family dwellings, 110 condominium units, and associated commercial/recreational areas, and is located entirely within the service boundary of the Diablo Water District (DWD).


The Project allows DWD to provide potable water, and Pacific Gas & Electric Company (PG&E) to provide natural gas service, to Delta Coves and Bethel Island through completion of the following Project components:

  1. Delta Coves off-site water trunkline

  2. Delta Coves off-site gas pipeline

  3. Chloramination plant

  4. Water Pump Station

  5. Water Reservoir

  6. Improvements to the existing Bethel Island Bridge Crossing over Dutch Slough

  7. Completion of a Water Line Loop (on-Site) within Delta Coves, extending under the existing levee breach between Delta Coves Drive and Windsweep Road

Analysis for this Project included:

  1. Northerly Segment of Waterline within Bethel Island Road: A segment of 18-inch Water Trunkline north of Bethel Island Bridge will be placed within the existing right-of-way, and is anticipated to be installed along the west side of the existing roadway, connecting to the internal Delta Coves on-site water line at Sandy Lane.

  2. Segment of Gas Pipeline within Bethel Island Road: 8,200 feet of 6-inch Gas Pipeline along Bethel Island Bridge will be placed within the existing and future street right-of-way south of Dutch Slough, and within the existing street right-of-way north of Dutch Slough, connecting to the existing Delta Coves gas pipeline at Sandy Lane. The portion which crosses the Bethel Island Bridge will be encased in 10 inch steel casing which will be installed by using 6 inch by 10 inch spaces and 10 inch pipe hangers.

  3. Diablo Water District Facilities within Delta Coves Project Boundary: The certified EIR for the Delta Coves development anticipated a common system for the treatment and delivery of potable water to the future residents of Delta Coves. The analysis, however, was not specific as to the physical location and footprint of certain facilities included in the current Project, including the Water Pump Station, Chloramination Plant, and Water Reservoir. The MND analyzed these components.

  4. Internal Loop Connection - Proposed Breach Water Line Undercrossing: The Project includes a 1,083 foot long pipeline, composed of approximately 320 feet of pipe to connect a 733 foot horizontal-directional drilled segment of 12 inch fused PVC water line (to be placed inside of a 16 inch fused PVC casing) which will be connected to existing water lines within Delta Coves Drive and Windsweep Road to complete the loop necessary to deliver sustainable water pressure and volume for fire protection purposes. This connecting segment of water line within the Delta Coves community will be extended under the existing levee breach.