The Manhattan City Commission voted Tuesday night to build a Storm Detention Pond East of the Manhattan Corporate Technology Park. The detention pond will help stop flooding in an area East of the Manhattan Airport. The pond will help future development in that area. (See Editorial on page one)

BACKGROUND

As part of the deliberations and eventual purchase of property for the Manhattan Technology Park, it was recognized that storm drainage issues were of critical importance. Those issues pertain to the Park, the Regional Airport, and the surrounding properties in the area, especially those downstream of the Park. The City made a commitment to address those issues. On June 4, 1998, a contract was executed between BG Consultants, Inc. and the City of Manhattan. The scope of the project was divided into two (2) parts, each with a "study" and a "design and construction document" component. The first part dealt with immediate concerns because of the construction of the Sykes development. The second part focused on future concerns because of projected developments.

The study for the first part of the project was completed in July 1998. It was in conformance with the Manhattan Corporate Technology Park Master Plan, and with the Storm Water Management Master Plan. BG Consultants, Inc. was authorized to proceed with the preparation of construction documents for detention basins associated with the Manhattan Corporate Technology Park.

In November of 1998, the City Commission awarded a construction project to Bayer Construction for the construction of the first detention basin. That construction project was completed in 1999 at a cost of $95,211.00.

Expansion of the park has necessitated the implementation of a second basin to adequately address the additional runoff in accordance with the Storm Water Management Master Plan.

DISCUSSION

Bids were received on October 3, 2001, for the construction of a second storm detention basin. The basin will be dry except for short periods of time after intense rainfalls. The basin will occupy some land on airport property. Ken Black, Airport Director, has been consulted as part of the process and advises the project is in conformance with Airport regulations and plans.

The discharge from the basin will be regulated so that developed flow rates from storms with return frequencies of two (2), ten (10), and one hundred (100) years will all be less than flow rates for the same storms under existing conditions. What that means is that the properties downstream should see runoff after development at lower rates than existed prior to development of the technology park.

There were three (3) bids received as shown on the attached Bid Tabulation Summary. An Engineer’s Estimate in the amount of $190,500 was provided by BG Consultants, Inc. Big River Construction Company, of Nebraska City, Nebraska, submitted the low bid in the amount of $135,373.30.

The project is included as part of the overall "on-site storm drainage improvements" described in the Manhattan Corporate Technology Park Master Plan. The payment for this phase will be paid out of the Storm Water Management Fund. There is sufficient budget authority and cash in the fund to make the expenditure.