E.S. Wagner was the prime contractor on the initial phase of an initiative to increase the overall capacity of the water system servicing Allen County, Ohio and the City of Lima. The Lima Up Ground Reservoir was designed to retain around nine billion gallons of water and covered nearly one square mile. With embankments reaching forty-five feet above existing ground and a bottom excavation averaging around fifteen feet, the total height of the reservoir walls extended to more than sixty feet when measured from the floor of the containment.
With an April start and utilizing as many as four high-production earthwork crews simultaneously and on multiple shifts, E.S. Wagner Company was able to excavate the almost 4.5 million cubic yards of material required to complete the planned embankments by the fall of the same season. Since the reservoir was designed to hold water without leaking, the condition of the embankment material had to be maintained in an almost perfect condition with respect to moisture content and compaction, all without compromising productivities that reached well in to the thousands of cubic yards per hour.
Prior to construction of the embankments, a blanket drain had to be installed beneath a portion of the footprint of the fills. Consisting of over 80,000 tons of a small diameter and free draining aggregate material, this drainage layer was design to control the potentially detrimental impacts of water piping beneath the reservoir.
Along with the construction of the main containment embankments, E.S. Wagner also relocated a wetland that was to be disturbed during the excavation of the reservoir and constructed the influent and effluent structures that served to control the amount of water retained in the reservoir at any time. These two structures, along with a boat dock and ramp, consisted of around 850 cubic yards of structural concrete and included the mechanical valving and over 900 feet of 42” and 54” ductile iron piping that would eventually make the system functional.
Storm water runoff was maintained through a vast underground drainage network that consisted of over three miles of storm sewer ranging in size from 6” to 42” and included 55 drainage structures.
Finally, due to their functional purpose and obvious exposure to soil erosion, reservoirs embankments must be carefully protected. The Lima project required E.S. Wagner to place almost 90,000 tons of inboard slope protection that was installed in two steps over a blanket of filter fabric. The first layer of slope aggregate consisted of a smaller diameter stone that protected the slopes and filter fabric from the final course, a much larger course of rip rap. This was no small endeavor as all the aggregate materials had to be transported to the top of the completed embankments by conventional on-highway trucks and then placed on the slopes – with all the equipment sharing a roadway that was only wide enough for a single lane of traffic.