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<br />tit <br /> <br />. <br /> <br />. <br /> <br />Other requirements included obtaining a stormwater discharge permit. By far, the most time-consuming <br />process was hydraulic modeling. Duplicating the regulatory model was quick and routine. However, <br />creating a present conditions model was more labor intensive. Conditions on the DOC property, on which <br />construction was underway, needed to be included. In addition, DOC consultants were developing an <br />application for a Conditional Letter of Map Revision (CLOMR) to remove the jail facilities from the <br />floodplain. This required close coordination with the DOC consuitants and obtaining timely information <br />from them. There was also some concern as to how to handle the CLOMR within the Bluff Lake submittal. <br />Denver officials indicated that since the CLOMR hadn't been accepted by the Federal Emergency <br />Management Agency (FEMA), the proper procedure was to base all work on the current regulatory model. <br />Until the regulatory model and floodplain has been revised with a Letter of Map Revision (LOMR), it would <br />remain as indicated. Denver is not interested in revising the floodplain through the Bluff Lake Park site, <br />since it will remain relatively undeveloped and continue to act as a flood storage area. <br /> <br />This permit took approximately four months to be issued, potentially posing a major delay to construction <br />activities. It was decided, and agreed to verbally by WWMD, to mobilize and begin work that remained <br />outside the channel. This work included site setup, clearing and grubbing, and excavation of the channel <br />realignment reach. In addition, the boulder toe along the riprapped channel bank protecting the VCUP <br />was reset and the riprap revetment was topsoiled and seeded and covered with coir matting to provide <br />additional protection to the VCUP slurry wall. This work was completed just as the floodway development <br />permit was issued and work could begin in the stream channel. Creative scheduling between staff <br />responsible for the permit application and the contractor eliminated any potential delay in the project. <br /> <br />Probably one of the most important aspects of design/build came during the construction period. By the <br />time the contractor had mobilized, he was thoroughly familiar with the proposed improvements having <br />worked on the project through the design period. In addition, relationships and familiarity between teams <br />were well-established. This allowed both the construction and design teams to work together to establish <br />realistic schedules that addressed constraints both in design and construction and to develop solutions to <br />problems that crept up, including timing, permit delays, and field changes in design. Regular visits to the <br />site by the design engineer, and continuous communication between the engineer and contractor, resulted <br />in minimal inconvenience and maintained the construction schedule. <br /> <br />One problem that is difficult to overcome on any channel improvements project, but is probably more <br />critical on design/build projects that often are fast-track, is coping with unpredictable weather, or weather <br />that is predictable, but can't be avoided. The ideal start date for construction was chosen as late August. <br />This date is towards the end of the monsoon season that brings almost daily thunderstorms and the <br />highest flows experienced on Sand Creek. Mobilizing in late August would allow the contractor nine <br />months to complete the improvements before the next monsoon season started. However, construction <br />did not start until January, allowing only four months before the monsoon season. This meant the <br />contractor had to work through thunderstorms during the following summer, that gradually intensify <br />through July, to complete the work. Although on this project down-time due to loss of water control was <br />minimal, it probably delayed the project about a total of one week. Good water control will minimize this <br />problem, however, the unpredictability of weather introduces a large random variable that results in the <br />inability to correctly anticipate site conditions. Therefore, fast-track design/build projects need to take this <br />into consideration early in the process to target the best time for construction to start. If target dates are <br />missed, then, as in the case of Bluff Lake, schedules have to be compressed as much as possible, the <br />contractor needs to prepare for adverse conditions assuming the target end date will also be delayed, and <br />the owner/client needs to be made aware that future unforeseen circumstances have a higher probability <br />of occurring that may delay the work. This is particularly important when design/build projects are driven <br />by regulatory or litigation conditions. <br /> <br />CONCLUSION <br /> <br />In summary, problems associated with this project included: <br />