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CR 96-75 Engineering Services - Meadowbrook Storm Sewer1 April 11, 1996 Proposed Action. Overview. Primary Issues to Consider. • Description of proposed project • Costs • Project Schedule • Staff recommendation Supporting Information. • Analysis of Issues • RCM letter proposal • Preliminary Engineering Report Steven J. Stadler, Director of Public Works Council Report 96 -75 AUTHORIZE ENGINEERING SERVICES MEADOWBROOK STORM SEWER, PROJECT #95 -15 Staff recommends the following motion: Move that Council authorize the Mayor and City Manager to enter into an agreement for professional services related to the Meadowbrook/Interlachen Park storm sewer project. At the January 16, 1996 meeting, City Council authorized RCM, Inc. to prepare a study of the stormwater issues relating to a Meadowbrook storm sewer improvement project. RCM has prepared the report and it is attached to this Council Report. The report contains pertinent information, including constraints impacting our project, from the City of Edina, Meadowbrook Golf Course, Minnehaha Creek Watershed District and Interlachen Country Club. Despite the constraints, a viable improvement project is possible. Further, the project is best completed in a single phase, not a three -phase • approach as described in the OP. Staff held a public information meeting on this proposed project at 7:00 p.m. on April 9 ' only two residents attended. However, staff had the opportunity to explain the project and answer questions due to several telephone inquiries received prior to the meeting . Council Report #96 -75 Page 2 Analysis of Issues • Description of proposed project The project would improve storm drainage in the southeastern Interlachen neighborhood by installing a new 15 inch storm sewer pipe to replace an existing deficient 12 inch pipe which runs into the Meadowbrook Golf Course system. The proposed alignment of the new pipe would be from an existing manhole near the Interlachen Park shelter building, south onto Interlachen Golf Course, then east connecting to a City of Edina storm sewer manhole just north of Annaway Drive. Lateral pipes would be extended to connect to the existing storm sewer at the south end of Hawthorne Road and Meadowbrook Road. This pipe alignment costs less and would be much less disruptive to trees and fences in the area. The alignment would require an easement from Interlachen Golf Course. Due to Minnehaha Creek Watershed District constraints, we cannot tie into the City of Edina system with a pipe any larger than 15 inches. Therefore, while the project will • provide a noticeable improvement for the area, the improvement is less than it could be without the 15 inch pipe restriction. In order to increase capacity, our design would have to include a stormwater detention pond in Interlachen Park. Fortunately, this is not necessary to achieve an acceptable improvement for this drainage area. . Costs RCM, Inc. has proposed an engineering services fee of $20,900. This is a reasonable fee considering there will be considerable effort needed to coordinate approvals from the various agencies, process easements, and obtain permits. The preliminary estimated construction cost is $108,000. The CIP budget was set for a 3 -year (1996 - 1998), 3 -phase project estimated at $50,000 each year. • City Council Report 96 -75 Page 3 • Project Schedule May 31 Complete survey, obtain alignment approvals Jun 21 Design completion, obtain permits Jul 2 Approve design, order bids Aug 6 Award contract Sept -Oct Construction Note: The project schedule could change to allow bidding later in the year if staff determines this would result in a more favorable bid climate. • Staff Recommendation Staff recommends approval of the engineering services agreement with RCM, Inc and approval of the design as described above. car muller *associates, inc. ears architects land suNeyors equal opportunity employer 10901 red circle drive box 130 minnetonka, minnesota (612) 935 - 6901 fax (612) 935 - 5814 April 11, 1996 Mr. Steven Stadler Public Works Director City of Hopkins 1010 First Street South Hopkins, MN 55343 RE: Engineering Services Proposal Meadowbrook Area Storm Sewer RCM File No. 10350.00 Dear Mr. Stadler: RCM is pleased to provide this engineering services proposal for design and construction phase services related to the Meadowbrook/Interlachen Park storm sewer upgrade. The proposed project will involve replacement of an existing storm sewer which drains through Meadowbrook Golf Course. The project will extend from the existing City of Edina storm sewer in Meadowbrook Golf Course, and will extend west to Homedale Road. The alignment will be generally through Intertachen Golf Course, as described in our report dated March 6, 1996. This proposal is based on the assumption that the project will not include pond construction. Engineering services for the Meadowbrook Storm Sewer project will be provided in three phases as described below. Meetings. Coordination. Easements and Permits Phase RCM (accompanied by City staft) will meet with the City of Edina, City of Minneapolis Park Department, managers of the Meadowbrook and Interlachen Golf Courses, Minnehaha Creek Watershed District, and affected property owners. These meetings will resolve design issues such as alignment, scheduling, coordination with golf course operations, easement needs, restoration, and permit requirements. Also as part of this phase, RCM will prepare and submit permit applications, and will prepare legal descriptions for permanent easements for the new storm sewer. Final Design and Bidding Phases RCM will perform design surveys and prepare drawings, specifications, and contract documents for the proposed project. Our proposal is based on the entire project from Meadowbrook Golf Course to Homedale Road being constructed under a single contract. Following acceptance of the drawings and specifications, RCM will assist the City with advertising and receiving bids for the project. 55343 -0130 Mr. Steven Stadler April 11, 1996 Page 2 Construction Phase RCM will provide construction phase services as requested by the City. We understand the City will assign one of its own personnel as on -site Resident Project Representative. RCM's services will include: • Attending preconstruction conference • Shop drawing review • Review of contractor pay estimates and change orders • Answering questions related to the design • Periodic she visits (up to 30 hours) to observe construction and assist City's Resident Project Representative • Record drawings Schedule RCM ASSOCIATES RCM will commence work on meetings and coordination as soon as authorization is received from the City. Completion of this work is dependent on factors beyond our control. For scheduling purposes, we have assumed that design issues such as alignment, restoration, and easement needs will be resolved within 30 days after authorization to proceed. Once these issues are resolved, the City will authorize RCM to proceed with final design. Final design will commence after the alignment is defined and the City authorizes work to begin on final design. Drawings, specifications, and legal descriptions for easements will be submitted to the City for review within 60 days after our receipt of City's authorization to proceed with final design. Construction phase services will be provided in accordance with the Contractor's schedule. Our proposal is based on the assumption that storm sewer construction will be completed in the fall of 1996. Compensation For meetings, coordination, easements, and permits, RCM will be compensated on an hourly basis at our actual hourly rates plus overhead and profit, plus actual cost of reimbursable expenses. RCM's billings to the City for these tasks will not exceed $5,000 without prior written authorization from the City. For final design and bidding assistance, the City will pay RCM a lump sum of $10,900. For construction phase engineering services, RCM will be compensated on an hourly basis at actual hourly rates plus overhead and profit, plus reimbursable expenses at Mr. Steven Stadler April 11,1996 Page 3 actual cost. RCM's billings to the City for construction phase services will not exceed $5,000 without prior written authorization from the City. We appreciate this opportunity to serve you. If you would like us to proceed, kindly sign the bottom portion of both original copies of this proposal, and return one copy to us. Kcep the other one for your files. The signed proposal would serve as the agreement between the City and RCM, Sincerely, RIEKE CARROLL MULLER ASSOCIATES, INC. t aagt - Dale A. Folen, P.E. Assistant Manager, Water Resources Accepted by: Rieke Carroll Muller Associates, Inc. 094 te-V, RCM ASSOCIATES Sam L. Claassen,P.E. President/CEO Mayor �iarYy Koutsoumbos, P -E- Vice President Paul W. Blum, P.E. Manager, Municipal Engineering City of Hopkins, Minnesota Charles Redepenning Steve Mielke City Manager Dated: April 11. 1996 Dated: tm rieke carroll moiler associates, inc. meers itects nd surveyors equal opportunity employer 1 red cirele drive '15bx 130 minnetonka, Minnesota (612) 935 -6901 fax (612) 935 -8814 / 55343 -0130 March 6, 1996 Mr. Steven Stadler Public Works Director City of Hopkins - 1010 First Street South " Hopkins, MN 55343 RE: Preliminary Engineering Report Meadowbrook / Interlachen Park Storm Sewer RCM File No. 10350.01 Dear Mr. Stadler: Affected Parties We have completed our study of the Meadowbrook / Interlachen Park storm sewer upgrade according to our Agreement with the City dated January 11, 1996. This letter report summarizes our findings. We welcome the opportunity to discuss this project further with city staff and the City Council. - The proposed project will involve replacement of an existing storm sewer that drains through Meadowbrook Golf Course. The downstream end of the storm sewer will connect to a newly constructed City of Edina storm sewer in the southwestern part of Meadowbrook Golf Course. The storm sewer will eventually extend upstream to Interlachen Park, at the southern end of Homedale Road. Several parties could be affected by construction of the proposed storm sewer beyond residents of Hopkins. The following discussion summarizes the primary issues, based on initial discussions with each organization. Edina . The City of Edina has constructed part of the outlet storm sewer for the proposed Hopkins storm sewer, and is planning to construct the rest of the system during 1996. Edina has allocated some capacity in the new storm sewer system for draining runoff from a small watershed in Hopkins. Edina has requested that Hopkins limit the discharge to be equal to the gravity flow capacity of a 15 -inch pipe. -The- existing storm sewer in Edina is under Annaway Drive, extends upstream though the yard of a home at 4603 Annaway Drive, and ends at the border between that property and the Meadowbrook Golf Course. The remaining storm sewer, to be constructed this year, will be aligned under Malt Lane, Merilane, and through the Meadowbrook Golf Course to a pump station and pond on the edge of Minnehaha Creek. Mr. Steven Stadler March 6, 1996 Page 2 At the comer of Mait Lane and Annaway Drive, the new storm sewer is proposed to be set about 4 feet higher than the existing pipe. This will cause the pipe under Annaway Drive and the private yard to always be submerged. Edina would like Hopkins to install at least one sump manhole to remove grit from the runoff. The City of Edina is planning to contact Hopkins about cost sharing. They have estimated the contributing watershed area split to be 60 percent in Edina, 30 percent on Minneapolis Park Board Property, and 10 percent in Hopkins. Meadowbrook Golf Course The Minneapolis Park Board is the owner of this golf course. The proposed project will benefit the golf course, because the existing storm sewer (or drain tile) across the course reportedly surcharges and damages turf areas during heavy rainfall events Due to the location of the Edina storm sewer, Hopkins must coordinate with the Minneapolis Park Board to develop an agreement for an acceptable storm sewer route. RCM has sent a sketch of options to the Head of Operations for the course, and requested their recommendations for the preferred route. Park Board staff mentioned a couple of general restrictions for the work. First, the entrance to the course must always remain open. Short term blocking of the access road to the "cart shack," near the proposed storm sewer, should be possible. Second, the Park Board does not want to allow removal of any mature trees. The proposed project can probably work within these restrictions. At the start of design, the actual route across the golf course property should be established by a site visit with golf course and park board staff. The final plans must be submitted to the Park Board for review and approval. Minnehaha Creek Watershed District The Watershed District has jurisdiction over the watershed area of the proposed storm sewer. The City of Edina and the Meadowbrook Golf Course have an agreement with the Watershed District regarding operation of the pump station that drains the proposed Edina storm sewer and other land on the golf course. When the water level in the Creek is too high, the pump station must not operate. Runoff will collect in the pond on the golf course until the creek level decreases Edina has not yet submitted a permit application to the District for the storm sewer segments planned to be constructed in 1996. Hopkins should submit a permit application after or concurrent with the Edina application. Mr. Steven Stadler March 6, 1996 Page 3 Interlachen Country Club Due to the limited space for the proposed storm sewer within Hopkins corporate limits, RCM met with the golf course superintendent to discuss the possibility of constructing the storm sewer partly on the property of Interlachen Golf Course. This course is within the Edina Corporate limits. Interlachen is willing to consider a storm sewer and easement across their property as long as the system can improve site drainage on the golf course. Specifically, they would like an overflow outlet for the ponds in the northeast corner of the course. They would also like a catch basin installed in the low tree and brush area south of Homedale Road. Construction on the golf course property should not occur during the months of June, July, or August. Heavy equipment must not cross the golf course, so the contractor will need access from the Hopkins side of the course. Golf course crews are willing to seed the disturbed areas to restore them, as long as finish grading is done by the contractor. Final decisions related to the project must be approved by the Interlachen Country Club Board of Directors. Design Criteria and Evaluation Typical design criteria for storm sewers in Hopkins recommend that pipes should carry the peak runoff rate from a 10 -year design storm. Building structures near ponding areas or flooding areas should be protected from flooding during a 100 -year design storm. Refer to section 2.4.5 in the Hopkins Storm Water Management Plan for further definitions. Minnehaha Creek Watershed District has rules that do not allow any increased runoff rates beyond existing conditions. The City of Edina has developed a plan, using ponding and a pump station in the Meadowbrook Golf Course, that allows a slight increase in discharge rate from Hopkins, but has the disadvantage of no discharge being allowed during flooding of the creek. The capacity allowance for Hopkins is equal to about 3 to 4 cfs. The conditions during pump station shut -down should not significantly affect Hopkins, since the excess water will be held on Meadowbrook Golf Course property. The available capacity is Less than the peak flow from a 10 -year design storm, but will allow runoff from that storm to drain away within about 13 hours. Runoff from a 100- year design storm would drain away in about 27 hours. Excess runoff will stand in the park area at the south end of Homedale Road and in the Interlachen Golf Course until it drains away. To increase the storm sewer capacity within Hopkins, or limit overflows to the golf course, a pond would need to be constructed in the park. Mr. Steven Stadler March 6,1996 Page 4 Standing water in the park area should not affect any homes along Homedale Road, since water would overflow into the golf course at a point at least 3 feet below the lowest home. Homes at the south end of Hawthorne Road will likely continue to experience street flooding as in the existing conditions, but the occurrence should be less frequent. Part of the existing problem at this point is due to the blocked pipe downstream (to be replaced), and part is due to the configuration of the cul -de -sac, with berms around it. To allow the new storm sewer pipe to drain completely between storms, the downstream end of the Hopkins storm sewer must be set at or above the overflow point in the Edina storm sewer. The preliminary design was based on an outlet elevation of 887.5 feet MSL as shown in the design plans prepared by the City of Edina. This elevation must be verified after construction of the Edina storm sewer so the downstream invert elevation can be adjusted accordingly. Pipe Alignment Alternatives Two pipe alignment alternatives were investigated. The first alternative is entirely in the Hopkins city limits, called the "Hopkins Alignment." The second alternative is partly on the property of the Interlachen Golf Course, called the "Interlachen Alignment." The starting and ending points of the two alternatives are the same. The Hopkins Alignment would connect to the upstream end of the existing Edina storm sewer at the city limits, pass on the north side of the Meadowbrook Golf Course cart shack, and continue west along the alignment of the existing pipe. At Meadowbrook Road, the catch basin would be replaced, and the pipe would turn south. About 10 feet north of the city limit, the pipe would turn west, and be placed parallel to the southern property lines within the existing utility easement. City staff is checking the documented status of this easement. In the park at the south end of Homedale Road, the pipe would turn north, and eventually connect to the existing manhole northeast of the park building (warming shed). The estimated construction cost for the Hopkins Alignment is about $120,000. This alternative has the advantage of being located entirely within the Hopkins city limits. However, it has the disadvantage of significant disturbance to existing trees, fences, and a tennis court that are within the easement. As many as 37 trees, 6 -inch diameter or larger. would need to be removed to construct the storm sewer along this alignment. These trees are the primary visual barrier between the golf course and the homes. In addition, a temporary easement would need to be obtained from the land owners since the construction could not all occur within the existing 20 -foot wide easement. The Interlachen Alignment would connect to the upstream end of the existing Edina storm sewer at the city limits, pass on the north side of the Meadowbrook Golf Course cart shack, but then turn southwest toward the Interlachen Golf Course. A storm sewer Mr. Steven Stadler March 6, 1996 Page 5 lateral would be placed along the existing alignment to drain the southern end of Meadowbrook Road. The main storm sewer would be aligned through the golf course to minimize tree loss. The pipe would be placed through the existing tree and brush area south of Homedale Road, then through the park, similar to the other alignment. Laterals would be extended to connect to the existing 12 -inch storm sewer from Hawthorne Road, and the golf course pond. The estimated construction cost for the Interlachen Alignment is about $108,000. This alternative would be less disruptive to trees and fences in the area than the other option. The route considered through the golf course would not affect any golfing areas. The primary tree losses would be confined to the tree and brush area south of Homedale Road, so the visual barrier would remain intact A few trees outside of this area could ✓ also be lost Implementation of this alignment will require obtaining an easement from Interlachen Country Club. Conclusion Construction of the proposed storm sewer will provide a benefit to the area. The existing storm sewer draining this area will be removed from the Meadowbrook Golf Course, leaving no outlet. Further, the pipe within Hopkins is substantially plugged or crushed, and does not allow video inspection to determine the cause of the problem. While the proposed storm sewer does not meet the standard design criteria for storm sewers, it will improve drainage in the area compared with the existing conditions. Either alignment is technically possible to construct. The City can select the most favorable option considering all of the issues. Splitting the project into two phases may be possible for the Hopkins Alignment, but is not recommended for the Intelachen Alignment. Please call with any questions. Sincerely, RIEKE CARROLL MULLER ASSOCIATES, INC. PDAIL- Dale A. Folen, P.E. Assistant Manager, Water Resources DAF(aec losure The capacity of the proposed 15 -inch storm sewer is equal to a design storm of less than a one year recurrence. Runoff from more intense storms will stand in the park at the south end of Homedale Road and overflow into the Interlachen Golf Course: The existing system operates this way, and the proposed system will allow the overflows to occur less frequently. The City of Hopkins may want to consider ponding in the park to reduce overflows to the golf course. The advantage of a pond would be to allow better storm drainage Side the City. For example, Larger storm sewers could be constructed to drain the land around Hawthorne or Maple Hill Roads to a pond. The design criteria for the pond could be selected by the City. Two possible pond sizes are shown on the attached drawings. The first figure shows a pond which would hold excess runoff from a 10 -year storm, and allow storm sewers upstream of the pond to be sized for that same storm. The cost of this option would be about $50,000 added to the cost of the storm sewer project. The second figure shows a pond that would hold excess runoff from a 100 -year storm. The larger pond construction would cost about $80,000. This estimate includes the cost of demolishing the existing hockey boards and reconstructing them in the bottom of the pond. 1 Hockey Rink High Water Level Pond Shape for 10 -Year Design Meadowbrook J Interlachen Park Storm Sewer Report 1 High Water Level Pond Shape for 100 -Year Design Hockey Rink Hopkins, MN Meadowbrook / Interlachen Park Storm Sewer Report - March 1996