City examines three alternatives for storm runoff

With continued development on the east side of Sidney, storm drainage has come under increased scrutiny. Development means more asphalt in the form of parking lots and roads—and these have a direct impact on the direction and energy of storm runoff.

In the absence of planning, heavy rains can cause flooding, erosion and structural damage.

The South Platte Natural Resource District held a recent meeting in conjunction with the city to hear the findings of an independent study, commissioned by Sidney and conducted by Olsson Associates.

At the meeting, Olsson Associates put forth three alternative plans. One continues to maintain existing drainage traps where possible, adding a development of 12 water quality ponds. Six of these bioretention ponds would be built in the Fort Sidney Road area, along with the construction of five vegetated bioswales (landscaped natural grass land).

All three dams would be removed and the current drainage pattern altered slightly to allow storm water to flow to the proposed bioswales. Additional hard drainage, pipes and culverts would be minimal, lowering the cost.

The plan also calls for the construction of ponds to be built on the west side of Sidney.

Alternative two would add three bioswales along the west side of the project area and three along the east side, converging all the water into Lodgepole Creek. Seven water quality ponds would be built.

As in the first plan, all three dams would be removed.

This alternative would also require the acquisition of new rights of way for drainage. It will also account a 10 to 20-year storm. Alternative one provides for a 100-year storm.

Alternative three would create five bioswales and seven water quality ponds, with a portion of the middle bioswales combined to create one large bioswale.

The benefit of the bioretention and bioswales would reduce water pollution in Lodgepole Creek.

Projected costs range between $4,324 and $4,558.