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Memo Nine Mile Creek Improvements -''::1', i'" e CITY OF HOPKINS MEMORANDUM DATE: . February 3, 1993 TO: Mayor and City council FROM: Lee Gustafson, Public Works Director SUBJECT: Nine Mile Creek Improvements On Wednesday, September 16, the Mayor, Public Works Director and Pete Carlson of RCM, appeared before the Nine Mile Creek Watershed Board 'of Managers. The purpose of this appearance was to discuss flooding problems that the City of Hopkins was experiencing. The flooding problems mentioned were the areas near 13th Avenue South and County Road 3 (Dennis Roof property), and also the Thermotech areas south of 5th Street South. The area of 11th Avenue South near the creek was .. also discussed due to the importance of this road and how it . sometimes floods during storms in excess of 100 year frequencies. The Board was given a brief history of these problems and given the attached let~er, petition, and action plan detailing how the City of Hopkins would like to address these problems. The Board subsequently approved th~ first phase of these improvements consisting of replacing the culvert under the Hennepin County Regional Rail Authority right-of-way, and constructing the ponds west of Thermotech. As we are all aware, the Watershed District is presently revising their water management plan to address new legislation that has been adopted over the last five years. They are also making revisions to the plan to include any improvements that may be needed throughout the watershed. Improvements that have been identified in the plan are generally eligible for 100% funding by the Watershed District. The Watershed District has recently started to gather information on potential improvements for their plan update. They have recently requested cities within the district to submi t proj ects to them by February 17 that cities would like to see included in the plan. Staff would like to take ......\ ~dvantage of this potential funding source, and submit flood _ improvement projects to the Watershed District. ,~-.:'>' .:.. ., '""'~,'>;:,'iw'" ,:,m 'T~~dj' -- r- The projects staff would like to. submit to the watershed District can vary in size, cost, and flood protection. For these reasons staff would like to discuss with the council the various scenarios that could be submitted to the watershed District. The scenarios are listed on the following pages and include structure improvments at the Soo Line Railroad, 11th Avenue South and 7th street south. The scenario, or flood protection level that is determined to be the best situation for Hopkins would be put into a resolution format for council adoption.on February 16. The resolution would then be presented to the watershed District the following night, February 17. staff's recommendation is listed at the end of the scenarios.. . . ~ _::::",..,.,. '. ;,.' . NINE MILE CREEK FLOOD PROFILE ALTERNATIVES \ . Alternative "A" Project Cost: $508.816 0 Lowers flood elevation' in the Thermotech area north of the Soo Line culvert, from 899.3 to 898. 0 Helps Thermotech, but is not the ideal solution. Thermotech'stirst floor elevation of the existing building is 898.37. A new addition would have to be built at 899, one foot above the 100 year flood elevation. Thermotech would like to build the addition at the same elevation as the existing building. 0 Relieves flooding of other properties but not to a significant degree. 0 5th street South would still have 3 feet of water on it during a 100 year storm. 0 Watershed Distract may prefer this alternative due to its low cost. . 0 Thermotech's cost to upgrade their culvert is $231,680. Alternative "B" proiect cost: $588.722 0 Lowers flood elevation in the Thermotech area from 899.3 to 896. 0 Good alternative for Thermotech's proposed future expansion conc~rns. 0 Good alternative for reducing flooding in other areas. 0 Watershed could probably be convinced that this alternative is better than Alternative "A". 0 Thermotechs cost .for upgrading their culvert is $247,522. Alternative "c" proiect cost: $664.100 0 Lowers the flood elevation in the Thermotech area from 899.3 to 893. 0 Best alternative for reducing flooding along Nine Mile Creek and on major roads. . 0 Alot of additional flood protection for very little cost compared to Alternate "B". -,-,. :~- " ., 0 Watershed District may not like us eliminating properties from being flooded and ultimately loosing 'ups.tream storage. 0 Watershed District may also not'participate in the. additional cost between Alternate "B" and "c" resulting in the city absorbing this cost. 0 Thermotech cost to upgrade their culvert is $397,312. The Thermotech cost identified in each alternative is to replace the structure that they installed years .' ago to . enable them to cross the creek between their various' buildings. The architect presentlY working wi th Thermotech has . indicated' that they may only need a simple bridge for their fork lift traffic thereby eliminating the need to replace the structure. RECOMMENDATION staff's recommendation is to have the flood elevation in the Thermotech area at or below 895. This elevation would provide a few more benefits than the 896 which' is listed in Alternative "B". However, to lower the elevation from 895 to 893 costs very little for the amount of flood protection received. staff therefore would like to pursue lowering the flood elevation in . this area to 893 as outlined in Alternative "C". ~ - - ~ ~ ---~~-~- '. FRI)~' ReM ~1TVA. J'ltl 2.. ~. 1 '~.?:. ,?: :r.=. P. .::: p . COST ESTIMATES NINE MILE CREEK CULVERT IMPROVEMENT HOPKINS, MINNESOTA ReM PROJECT NO. 1016.2.01 'PLAN A EJe.... 898.0 at Soo LIne Railroad Install 102" RCP @ Soo Line Railroad $209,000.00 Install 4' x. 6' RC Box @ 11th Avenue $78,000.00 Install 8' x 6' RC Box. @ 7th Street S90,000.00 Modification at Highway 169 S 15.000.00 Total Construction Cost $392,000.00 10% Contingency $39,200.00 18% Engineeri ng 577 .616.00 Total Project Cost $508,816.00 ~, . PLAN B Eley, 896.0 at Soo LIne Railroad Install 120" RCP @ Soo Line Railroad $253,600.00 Install 6' x 6' RC Bo~ @ 11th Av~nue $89,400.00 Install 8' x 6' RC Box @ 7th Street $90,600.00 Modifica tion at Highway 169 S20.000.00 Total Construction Cost $453,600.00 10% Contingency $45,360.00 18% Engineering $89.812.00 Total Project Cost $588,772.00 PLAN C Elev. 893,0 at Soo Line Railroad Install 120" RCP @ Soo Line Railroad $253,600.00 Reline Exieting 96" CSP @ 500 Line Railroad $40,000.00 Install S' x 6' RC Box @ 11 th A'I.:nue $99,800.00 Install lOt x 6' RC Box @ 7th Street $106.600.00 Modification at Highway 169 $25.000.00 . Total Construction Cost $525,000.00 10% Contingency $52,500.00 15% Engineering $86.600.00 Totl.i.l Project Cost $664,100.00 F P. tJ ~1 R C ~l ~1T F ~ . tn' :2. .::. t';.':.: .?: ::7 f""". .J .' , ,', ,~, THERMOTECH COST ,...... Elev. 898.0 Construction Cost $181,000.00 Contingency and Engineering 550.680.00 Total Project Cost $231 ,6~O.00 Elev. 896.0 Construction Cost 5193,400.00 Contingency and Engineering $54.152.00 Total Project Cost , $247,552.00 Elev.893.0 Construction Cost $310,400.00 . Contingency and Engineering $86.912.00 Total Project Cost $397,312.00 . ~~'~"'''''''' -I ,~ , . C I T Y 0 F H 0 P K I N S September 15, 1992 Mrs. Aileen Kulak, Chair Nine Mile Creek Watershed District 8300 Norman Center Drive Bloomington, MN 55437 Dear ~s. Kulak; The City of Hopkins presently has two areas along Nine Mile . Creek that consistently experience flood damage during high water flows less than 100 year storm events. These areas include the apartment complex east of 13th Avenue and north of County Road 3, and the Thermotech Building on 5th street South just west of the creek and . south of the Soo Line Railroad. The city also experiences flooding of 11th Avenue South, a major north/south connector, during 100 year storm events. The city would like to pursue finding solutions to these problems, and would like the Nine Mile Creek Watershed Districts assistance in doing so. The attached petition is being presented to the Board of Managers as a sign of the city's strong desire to make improvements along Nine Mile Creek to address the two flooding problems and the public safety matter that was previously mentioned. The petition furthermore indicates the city's commitment to working with the Watershed District on solving these problems while at the same time ensuring that. new problems do not develop as a result of any improvements. The city's intent for appearing before the Board of Managers on September 16 is to provide everyone with a better understanding of the flooding problems Hopkins is experiencing. Hopefully, by having a good understanding of the problems, the Watershed District can agree with the city . that solutions to these problems need to be found. The next step in solving these problems would be to then develop an action plan similar to the attached schedule that everyone can agree to. , 1010 First Street South, Hopkins, Minnesota 55343 612/935-8474 An Equal Opportunity Employer , . september~5, ~992 ,Page 2 The city of Hopkins has been informed tliat tile Watershed District will be updating their management plan over the next year. It is our sincere hope that the improveDients for solving these problems will be identified in the plan, and furthermore be identified for funding assistance. On behalf of the city of Hopkins, I thank you for listening to our concerns. Sincerely, rl~ Nelson w. Berg Mayor . ~ * - ~ ~~---~- t.{ .1 ~ PETITION . CITY OF HOPKINS Hennepin county, Minnesota WHEREAS, the city of Hopkins desires to reduce flooding along Nine Mile Creek that is presently causing property damage and impacting public safety and, WHEREAS, the City of Hopkins would like to construct improvements along Nine Mile Creek pursuant to the Watershed District requirements and, WHEREAS, the city of Hopkins would like to construct a segment of these improvements within the next four months in order to solve an immediate flooding problem near 13th Avenue South and County Road 3 and, WHEREAS, the city of Hopkins desires to maintain the current discharge at the city limits after constructing the improvements so as not to cause increased flooding downstream in neighboring communities and," . WHEREAS, the City of Hopkins is commi tted to working with the Watershed District to maintain water quality in the stream ... . and water courses as well as protecting and improving these streams and water courses wi th respect to hydraulic efficiency to provide the community with minimal flood damage. NOW THEREFORE BE IT RESOLVED, that the city of Hopkins, hereby petitions the Nine Mile Creek Watershed District to improve the watershed management plan within the City Limits of Hopkins to prevent reoccurring flood damage and furthermore request any financial assistance the District may be willing to grant. city of Hopkins September 16, 1992 . . .,;. .- ' ~ . ACTION PLAN NINE MILE CREEK IMPROVEMENTS HOPKINS, MINNESOTA SEPTEMBER 16, 1992 o City meet with Watershed to discuss flooding problems. o Watershed concur with city that improvements need to be made. o Watershed directs engineer to work with city to develop flood profiles and potential improvements specifically for 1992 improvements Hopkins is seeking to construct. SEPTEMBER 16 - OCTOBER 2, 1992 o Watershed engineer works with city to develop flow data for replacing structure under Hennepin County Regional Rail Authority (HCRRA) right-of-way and other related pondingimprovements. OCTOBER 21, 1992 . 0 City appear before Watershed District Board of Managers . - requesting approval of replacing .the HCRRA structure and constructing relatedponding improvements. city further requests reimbursement from Watershed District for structure replacement and ponding improvements subsequent to Management Plan being revised. OCTOBER 21 - DECEMBER 31, 1992 o Hopkins construct new HCRRA structure and ponding improvements. MAY 15 - JUNE 15, 1993 o Hennepin Parks constructs regional trail along HCRRA right-of-way over top of the new structure. 1993 o Watershed District updates plan indicating improvements needed in Hopkins. Watershed engineer continues to work with Hopkins developing improvements~ 1994 . 0 Remaining improvements constructed by Hopkins with funding assistance from Watershed District . --