Laserfiche WebLink
<br />3.6 Conclusions & Recommendations <br /> <br />Factors that may affect cost and design are re-routing the existing storm sewer through an <br />adjacent storm sewer system. This option affects design capacities downstream and <br />causes problems where downstream detention is located. Unless the receiving system has <br />the excess capacity to handle additional flows, this is not desirable. Furthermore, the <br />additional capacity required to relieve flooding in the subdivision for a 5-year even is on <br />the order of 100 cfs which would require a 54-inch pipe. <br /> <br />Another option is to purchase additional easements for drainage in the pipeline corridors <br />located along the western boundary of Fairmont Park East. This is possible if the space is <br />available both vertically and horizontally in the pipeline corridor for storm pipe or storm <br />sewer crossings. Additional considerations are the added review and coordination time <br />for each pipeline company to review. If a pipeline is to be relocated, the pipeline owners <br />usually request reimbursement for the relocation and most companies prefer to design the <br />location internally. <br /> <br />Each alternative listed here increase runoff that will require mitigation. The only location <br />to place mitigation for this project is within the HCFCD B I 06-02-00 channel from the <br />outfall downstream to B I 06-00-00. Table 6 represents the costs associated with <br />alternative which should be added to each of the alternatives listed above. To mitigate <br />within the channel, approximately 33 ac-ft of available storage can be achieve for <br />$770,000. <br /> <br />Each alternative will allow for the implementation of an overflow swale to be constructed <br />at Fleetwood Drive and Mesquite by lowering the pavement at the intersection <br />approximately I.O-foot with 50-foot pavement transitions between existing pavement and <br />proposed grade. The outfall pipe will require upsizing and replacement to accommodate <br />other utilities and design flow rate. There is a 22-foot drainage easement located between <br /> <br />3-5 <br /> <br />Klotz Associates Project No. 0127.009.000 <br />May 2009 <br /> <br />Fairmont Park East & Brookglen Drainage Study <br />City of La Porte <br />