The City of Delta and downtown businesses are already experiencing benefits from the stormwater project completed in June.
Ellen Michelson, city engineer, reports that the tie-ins from sump pumps have reduced the amount of water being conveyed to the wastewater treatment plant. On average, the reduction of approximately 34,000 gallons per day is saving $48.62 in treatment costs.
The sump pumps, located in the basements of many downtown Delta businesses, were formerly tied in to the sewer system. Now the storm water conveyance system carries water to two large detention ponds, one at 5th and Confluence Drive and the other on Kellogg Street.
Detention ponds allow settling to occur, which reduces the amount of selenium, sediment loads and total dissolved solids entering rivers and streams, Michelson explained.
The project included the installation of approximately 6,000 lineal feet of storm water pipe ranging in size from 18 to 54 inches in diameter. The project area encompassed 2nd Street from Dodge to Grand, 5th Street from Silver to Highway 50, and six blocks of alleys from 2nd to 5th on both sides of Main.
During the project, the city's contractor, Wells Excavating and Farming, also replaced water valves, lowered water lines, replaced concrete and asphalt, upgraded ADA ramps and paved the alleys from 2nd to 5th. Road reconstruction and pavement overlays will further improve street and drainage conditions in the downtown area, Michelson said.
The project cost was $1,561,221, which was supported with a two-thirds grant from the Colorado Department of Local Affairs.
Public works director Steve Glammeyer notes that with judicious planning, the project area was expanded while remaining in budget.
The effort actually began in 2008 with the development of a comprehensive stormwater master plan. The study, completed by URS, identified the downtown area as the number one priority.
Because there was no system in place to convey stormwater underground, it flowed through the streets. "And our streets can only carry so much water," Michelson said.
In addition to saving the expense of treating that stormwater, many businesses no longer have to furnish electricity to sump pumps around the clock.