City to review storm drainage systems

Design work on drainage basins citywide is in progress and city officials are looking for residents' ideas on the projects.

The design for the Shendoah Heights Detention Basin is about 75 percent complete. Officials from Carson City development services and the city parks department will present design work for the basin and a future park to residents Monday.

The Shenandoah and other drainage basins are part of Carson's freeway project. With an estimated cost for the basin between $825,000 and $950,000, Development Services Manager Mahmood Azad said he hopes residents will come look at what has been planned.

"This is going in their neighborhood," Azad said. "We want to make sure we're not constructing something that is totally at odds with their desires."

Drainage basins are basically large, dirt holes that hold water during storms.

Development service personnel will update city supervisors on the progress of six drainage basin projects Thursday. Total cost for the drainage system construction is around $5.9 million.

The Shenandoah basin is a seven-acre "step-child" between a retention basin and a detention basin, Azad said.

A retention basin holds flood waters until they evaporate or seep into the ground. A detention basin has an outlet that acts similar to that in a bathtub, Azad said. The outlet acts as a plug to let the water out slowly.

The Shenandoah basin has a small outlet, but will be expanded into a full detention basin by late fall 2000. Water will go from the outlet into a series of storm drain culverts under the freeway.

"(Upgrading the basin) allows for better drainage in the city and it will allow us to make sure the outflow is directed in a known area rather than an unknown area," Azad said.

Traditionally there is a 1 percent chance in this area that a drainage basin will fill up with water, he said. They plan the basins to hold a 100-year flood. He said the 1997 flood was less than a 100-year flood.

"We fixed the basin and now we have a hole in the ground. What do you do with a hole in the ground?" Azad asked. "We thought we'd turn it into a park."

Parks and Recreation staff have designed a conceptual rough draft of what a park in the area could look like. Parks Superintendent Scott Fahrenbruch said the project has no funding yet but will probably be funded with capital improvement monies.

"The whole idea is to take this rough draft concept to residents and see if this is what they want in their park or if they have some other ideas," Fahrenbruch said.

Azad said building the park in the basin won't be a problem because 99 percent of the time it will be dry.

"With that 1 percent of the time, as water comes in, it takes 48 hours to drain out," Azad said. "Just because a park is inundated over time doesn't mean anything will die. Nothing will float away."

Azad said the project could go out to bid as soon as November but could be sidelined by bigger drainage projects such as the roughly $1.2 million Timberline/Combs drainage facilities. Construction on the Shenandoah basin should begin in March or April.

INFO:

If you go:

What: Shendoah Heights Detention Basin Public Presentation

When: Monday, 5:30 p.m.

Where: Shendoah Detention Basin, Bonanza Drive.

Call Carson City Development Services 882-2355 for information.

Development Services personnel will update Carson City supervisors on the progress of the city's storm drainage program:

What: Carson City Board of Supervisors Meeting

When: Thursday, 1:30 p.m.

Where: Community Center's Sierra Room, 851 E. William St., Carson City.