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HomeMy WebLinkAbout06/02/2015 Levee 37 Tributary Area Drainage StudyProspect Mount Prospect Public Works Department INTEROFFICE MEMORANDUM TO: ACTING VILLAGE MANAGER DAVID STRAHL FROM: VILLAGE ENGINEER DATE: MAY 28, 2015 SUBJECT: LEVEE 37 TRIBUTARY AREA DRAINAGE STUDY (CONTRACT AWARD NOT TO EXCEED $117,000.00) Background Levee 37 was constructed by the Army Corps of Engineers to prevent Des Plaines River flood waters from reaching the properties west of River Road in Mount Prospect and Prospect Heights. Pump Stations #1 and 2 function as the release of the storm water from those subdivisions when high river levels restrict the normal gravity discharge of the storm sewer system. During high river level events, Tideflex check valves close to prevent river water from inundating adjacent properties via the storm sewer system. This modus was the cause of record flooding during high river level events in 1986 and 1987. The Tideflex check valves were installed in 1991 and have proven highly effective at preventing river water inundation. Levee 37, along with Pump Stations #1 and #2 were constructed in 2011. A principle assumption applied to the design of the pump stations was that the coincidence of high river levels and significant rainfall on the landside of the levee system was extremely remote. This assumption was based on an analysis of rainfall data and river levels recorded prior to 1990. As a consequence, the pump stations were designed to primarily rely on the normal gravity discharge to dewater the storm sewer system. The Army Corps of Engineers has described Pump Stations #1 and #2 as "nuisance" pumps", intended only to supplement gravity dewatering of the storm sewer. Unfortunately, on dozens of occasions, the properties west of River Road have experienced significant flooding due to the inability of the gravity discharge and pump stations to release water to the Des Plaines River at a sufficient rate. On all of these occasions, the gravity discharge has been occluded by high river levels and the landside of the levee has been subject to rainfall events unrelated to the river crest. Presently, the Village of Mount Prospect, City of Prospect Heights, and the Army Corps of Engineers are considering several options to increase the capacity of the existing pump Levee 37 Tributary Area Drainage Study May 28, 2015 stations. To accomplish this, staff is seeking to enter into a contract for a report that will provide an analysis of the existing drainage systems tributary to the pump stations, analysis of the pump stations capabilities and proposed capacity improvements, and recommendations for improvements which could prevent the described flooding. Discussion As permitted by the Qualification Based Selection process, the Village solicited Statements of Qualifications from 5 qualified engineering consulting firms. Each firm was asked to submit as part of their proposal the following information: 1. Resumes of key personal and related experience on similar type projects. 2. A summary of the firm's process to accomplish the required tasks. 3. A staff hour estimate for major phases of work. 4. A project schedule. Tasks that were identified to be performed included: 1. Topographic survey of drainage system 2. Hydraulic and hydrologic analysis of the existing drainage system 3. Analysis of the design and capabilities of the Army Corps pump stations 1 and 2 4. Recommendations for improvements to the existing drainage system 5. Recommendations for improvements to the Levee 37 pump stations 1 and 2 6. Recommendations to reduce flooding risk for properties with below grade garages 7. Identify potential funding sources for recommended improvements The consulting firms' statement of qualifications were reviewed on the basis of their understanding of our goals and their methodology of the design and construction process. They were rated (with a maximum score of 100 points) according to these specific categories: Background of Firm, Capacity to Perform Work, Understanding of Project, Related Project Experience, Project Schedule and Projected Work Hours to complete tasks. The rankings are: Christopher B. Burke Engineering, Ltd. 94 points Ciorba Group, Inc. 82 points Gewalt Hamilton Associates, Inc. 78 points Robinson Engineering 74 points Knight Engineers and Architects 72 points Discussions were entered into with the top two ranking consultants and Christopher B. Burke Engineering, Ltd. demonstrated a clear understanding of our project goals. They also provided examples of similar drainage studies for other municipalities which included analysis of pump stations. They have had significant experience working with the Army Corps and have accomplished analysis of portions of the Prospect Heights storm sewer system that will be part of this study. Because of their demonstrated experience and ability to perform the work, staff requested a cost proposal from Christopher B. Burke Engineering, Ltd. to perform the X Levee 37 Tributary Area Drainage Study May 28, 2015 tasks as identified. They submitted a not to exceed cost of $117,000.00 to complete the project. It is the opinion of staff that the work hours allotted are reasonable and the rate is competitive and comparable to rates of recent projects. Christopher B. Burke Engineering, Ltd. has established a highly regarded reputation in the field of drainage studies and satisfactorily provided engineering services for the Village of Mount Prospect on a street lighting project. Recommendation It is my recommendation that the Village Board accept the proposal from Christopher B. Burke Engineering, Ltd. for the Levee 37 Tributary Area Drainage Study for a not to exceed amount of $117,000.00. Please include these items on the June 2nd Village Board Meeting Agenda. A. Wulbecker I concur with the above recommendation. Sean P. Dorsey; Director of Public Works H:\Engineering\Agencies\Army Corps\Levee 37\Pump Stations Hydraulic Analysis\Consultant Rec Mm.docx