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<br />An Engineering Department official noted that storm drainage facilities at the new <br />Broomfield Town Center along 120th Ave. (US 287) were flowing full and performed <br />well on July 25. If the storm had been worse, businesses in this area may have <br />sustained significant damages. Recent drainage improvements along City Park <br />Drainageway were credited with preventing damages on July 25. The City official also <br />noted that a smaller event had just occurred a few days earlier that nearly flooded the <br />Us. West Communications building located in the floodplain at 120th and Sheridan. <br />The July 22 flooding was aggravated by a construction project that partially obstructed <br />the City Park Drainageway channel. The problem was immediately remedied, which <br />proved fortunate just three days later. <br /> <br />RESTORATION MAINTENANCE <br /> <br />In 1998 the restoration program completed $1,428,000 of work. Restoration projects <br />typically address isolated drainage problems where the solution involves small scale <br />construction. One hundred individual activities were completed during the year. A <br />major advantage of the restoration program is the opportunity to use it to react quickly <br />to local drainage needs. <br /> <br />An example of reacting to a drainageway maintenance need occurred in Brighton, <br />Colorado during the summer of 1998. City staff informed us that Line B, also known as <br />South Urban Channel, needed repairs. Line B was originally improved by the City of <br />Brighton and the District Design and Construction Program about 20 years ago. <br />Changes in the upstream reaches of the creek coupled with natural processes caused <br />sediment deposition to occur in the improved section. What was originally intended to <br />be an urban passive-recreation corridor was becoming a marshy and mosquito ridden <br />area. The channel was wide and flat-bottomed with a riprap-hned trickle channeL The <br />deposition was occurring in and around the trickle channel due to the frequency of the <br />smaller storm events and the roughness of the riprap. Our work included removing <br />the sediment as well as reshaping and resetting the riprap for much of the length of the <br />trickle channeL Not all the problems were solved, however. This section of Line B is <br />still awaiting an improved outlet to the South Platte River. <br /> <br />A similar opportunity to react arose in mid-1998 on what is called the Pinehurst <br />Tributary to Bear Creek in southwest Denver. At a rear-yard location, overland flow <br />was captured by an inlet and pipe system. Because of its setting the pipe inlet <br />frequently became plugged with debris. The result was that runoff could not enter the <br />pipe and would back up enough that the water, in its obligation to seek the lowest <br />point, would sweep around and through several homes. The final solution to this <br />problem was not in a maintenance project but in capital improvements that would <br />ultimately remove the homes from the floodplain. Such improvements had yet to be <br />planned, designed and built. Recognizing that it could be years before such <br />improvements would be made project planners hoped to make short term changes to <br />help the neighborhood, It was recommended that the inlet to the pipe be improved to <br />increase the amount of water it let into the pipe. This fell within the work the <br />Maintenance Program could perform. The inlet design and construction were <br />completed within a couple months. While the development of the master plan for <br />flood control improvements is still underway, the improved inlet will now provide <br />better water carrying capacity for the neighborhood than they had before. <br />