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About Ernst Engineering

The 2003 Colorado Construction Gold Hard Hat Awards
Outstanding Environmental Project

Sheldon Lake (City Park Lake) , Fort Collins, CO – Ernst Engineering performed the stormwater modeling and design services for this City of Fort Collins project linking Sheldon Lake to the City Park golf course detention pond with a new large storm sewer infrastructure system. Analysis and design was conducted to alleviate neighborhood flooding in the area. Ernst Engineering conducted stormwater hydrograph routing, storm sewer system conveyance and detention pond modeling using SWMM.

Ernst ProjectFollowing the severe flood of 1997, the City of Fort Collins raised its rainfall criteria, updated its master drainage plans, and identified a number of new projects - one of these is the Sheldon Lake Drainage Improvement Project.

The initial purpose was to remove more than 250 structures from the 100-year floodplain by increasing detention in the lake and golf course.

Improvements included enhanced water quality in the lake, habitat structures for game fish, repaved streets, new curbs and gutters, a signature hole on the golf course, a new detention pond and an extensive stormwater system under a major arterial street. Stonework with an artist's touch added to the appearance of the lake and golf course.

Concrete walks also function as weirs, providing additional drainage controls.

The most critical challenge on this project was removing more than 100 years of accumulated sediment at the bottom of the lake. First, more than 20,000 fish were removed and relocated. Then after the lake was drained, a two-month process began to scoop the sediment into 32 dump trucks, which performed 4,300 hauling trips. Approximately 54,000 cu yds of material were used to revegetate a natural area, saving landfill space.

By accurately timing the various critical activities, city departments saved money by sharing costs and coordinating construction efforts. Timely construction of the project - $4.3 million in five months - allowed access to the areas for the summer season.

The new golf course detention pond required raising a green and re-constructing three tee boxes. Golfers temporarily gave up two strokes but now appreciate the new challenges added to the course. Park visitors are enjoying paddle boats on a clean lake, new pedestrian and bike paths, and the view from new stone overlooks on the shore.