Loading...
Supplemental Flood Protection MeasuresMasterpiece on the Mississippi TO: Michael C. Van Milligen, City Manager FROM: Don Vogt, Public Works Director SUBJECT: Supplemental Flood Protection Measures DATE: March 16, 2011 Dubuque bitild M- AmedcaCity 11111 r 2007 INTRODUCTION The purposes of this memorandum are to provide information and recommend a course of action for your consideration regarding next month's Mississippi River flood crest. DISCUSSION The Engineering Department is reporting that Mississippi River flood waters would encroach into the Mystique Ice Arena whenever the river reaches 29.5' (as commonly measured at the U. S. Army Corps of Engineers' East 4 Street river gauge). At this level, the floodwall would still protect the city and the Mystique's main casino would still be dry. So, other than the two marina properties (Dubuque Marina and Dubuque Yacht Basin), the new ice arena would be the first major facility flooded by the river if it surpasses our current record by more than 2.5'. We have taken measurements and it would appear that @85 HESCO flood barriers would be needed to protect the Arena. They would be used to form a 1,270' long and 4' high ring- shaped barrier. Since the Mystique Ice Arena is a City -owned facility, I recommend that the noted units be ordered immediately. In the event that they are subsequently not needed, they would of course be stored for future flood events. And even if they are used, unlike sandbags, they can be dismantled, stored, and reused in future years. The Engineering Department surveyed Dubuque's floodwall over the last week to confirm wall -top elevations every one hundred feet along its entire 6.5 mile length. The survey confirmed that the entire floodwall protects the city from a rough water flood crest of up to 30', with an additional 3' of wave protection. However, since Dubuque's floodwall has never been tested above 25.4' (4- 21 -01), there is always the question as to how it will perform if the river should approach the floodwall's maximum design capacity. For that reason, I recommend that the City also immediately order /purchase additional HESCO flood barriers in the case that they are needed to stabilize a section or sections of the floodwall in the event of a developing breach at elevations lower than the "overtopping" elevations noted immediately above. I am also recommending that a skid - steer - mounted sandbag filler be immediately purchased. Street and Sewer Maintenance Supervisor John Klostermann's consultation with other Iowa communities that battled the 2008 floods revealed Iowa City's endorsement of this tool for quickly filling sandbags. Information regarding the unit accompanies this memorandum. A twelve bag unit costs $6,750 and can be delivered to us within a week. The FY13 Capital Improvement Projects Budget includes a $300,000 appropriation for the purchase of approximately 645 HESCO flood barriers. In light of the above -noted concerns and possible needs, I recommend that the HESCO flood barrier purchase scheduled for FY13 be made now. Budget Director Jennifer Larson has indicated that adequate Stormwater Fund monies are now available for the recommended purchases of the HESCO flood barriers and the skid -steer sandbag filler due to the City's recent success in securing stormwater grants and a forgivable loan for the Bee Branch Creek Restoration Project. The purchases of the HESCO flood barriers and the skid -steer sandbag filler would be subject to a budget amendment. ACTION STEP 1 respectfully recommend the purchase of approximately 10,000 feet of 4 feet tall HESCO flood barriers at a cost of $300,000 and a skid -steer sandbag filler at a cost of $6,250 to help protect the Mystique Ice Arena and other parts of the levee during the upcoming record breaking crest of the Mississippi River. The purchase of the HESCO flood control units and the skid -steer sandbag filler would be included in the next budget amendment scheduled to go to City Council in April 2011. CC: Jenny Larson, Budget Director Attachments HESCO Bastion USA Waterways Controlling the forces of nature can be daunting and, at times, impossible. HESCO Concertainer units are an innovative way to protect property and lives threatened by the forces of water. Traditional methods for controlling flood water are now being replaced increasingly by Concertainer products. In the event of a flood warning, HESCO Concertainer units can be deployed quickly and easily to construct flood defenses without the need for specialist tradesmen or equipment — making it ideal for emergency response. Whether the increase in water level is gradual or due to sudden surge, Concertainer units and Floodline units provide a comprehensive solution to a wide range of flood- defense requirements. Use Examples, opposite, or go to Projects, for brief or detailed information on the successful use of Concertainer products in waterway projects. Back © Copyright 2010. International and US Patents apply. All Patents, Trademarks and Copyright used under license. httn: / /www.hesco.com/US CIVIL /waterways.html ProJucts Product range Contact us About us Examples click lrnag to enlarge Page 1 of 1 Projects click for News and archive Site map 3/16/2011 HESCO Bastion USA izinetrt Pr: ;uci° What is Concertainer? One system, five products The patented Concertainer design provides a cellular structure, using a welded mesh framework and geotextile lining. When joined and filled, the system can be used to create walls of exceptional strength and structural integrity. All products are pre - assembled and delivered packed flat, with joining pins to enable the connection of individual units. The five products are the Concertainer unit; Floodline unit — a specialized flood - protection unit; Rockface — a part -lined gabion; Rockbox — an unlined cellular gabion; and the Delta unit - a new wetland protection product. For more details, please use the links below. Concertainer® unit Concertalner Floodllneg' unit Concerteiner Rockface unit Concertalner Rockbox ID unit Concertalner Delta" unit Simple and ft fliclent Tested to the limit © Copyright 2010. Internati onal and US Patents apply. All Patents, Trademarks and Copyright used under license. http: / /www.hesco.com/US CIVIL /products.htrl Page 1 of 1 Non -woven geotextile liner Product rorxje Spiral - hinged come Contact us About us unfilled C -3315 unit weighs only 1051bs, so units can be easily manhancfed into position e geotextile lining is avaiabte in either sand or green color Galvanized welded mesh frame Nervs and archive Site map Legal disclaimer 3/16/2011 ESCO Bastion USA Homo ['roduCLs Appl:eatiorts Pfajects Floodline A geotextile -lined unit for use in flood - protection applications. The design of these units reduces permeability of the wall, when filled. Floodline units are designed for easy removal and are suitable for filling with earth, sand, or well - graded gravel. Floodline units may also be used in other applications. . There are two standard sizes of Floodline units: F -3315 and F -4315, as shown. Joining pins are supplied to join units together. Plastic ties are supplied to close the geotextile together at the top of unit ends, which prevents fill material from falling between unit joints. General specifications Geotextile lined welded wire fabric gabion to ASTM A 974 -97. Welded Mesh, coils and pins Hesco Concertainer units are manufactured with a Alu -Zinc coated welded wire mesh. The mesh has a spacing of 3" x 3" and a wire gauge of 8.5 American SWG, steel /diameter of 0.155 " /3.937mm (nominal). Geotextile The geotextile is a heavy -duty, non - woven, permeable, polypropylene fabric, available in either green or sand color. Detailed specifications For detailed technical specifications on Floodline units, or all HESCO Bastion USA products, use the links below: > Floodline Technical Specification Sheet > All products Technical Specification Sheets Back F -4315 Pr,;ust r.?nte F -3315 H -3' W -3' L -15' (5 cells) H -4' W -3' L -15' (5 cells) © Copyright 2010. International and US Patents apply. All Patents, Trademarks and Copyright used under license. ttp://www.hesco.com/US_CIVIL/floodline.html 3 , Contact us News and archive Page 1 of 1 Site map Legal disclaimer 3/16/2011 The design of this unique sand bagging machine is a skid -steer attachment which allows the operator to fill twelve (12) 14" x 26" poly or burlap sandbags at the same time. Simply attach the bags, scoop the sand, or other material, tilt the bucket back up which fills all twelve bags; drive to your desired location, tilt the bucket and release the hydraulics. Your bags are left standing and all that is left is to tie the bags and place them in position. This attachment is a must for not only municipalities and others involved in flood control, but also for erosion and sediment management, construction crews and landscapers. Any material that can flow into a bag can be filled faster and with more ease using this sand bagging machine, the Pro Bagger®. Pro Bagger