Authorizing a contract Amendment 1 with WHKS, in the amount of $43,770 for the final design of Upgrade/Replace Zumbro River Siphon at Silver Lake and Sewer Extension - Project No. J7829.

Upgrade/Replace Zumbro River Siphon at Silver Lake and Sewer Extension - Project No. J7829 was identified as a high priority project during the development of the Sanitary Sewer Master Plan and is needed to provide additional capacity to the East Zumbro sewer shed. The siphon is the first of several capacity improvement projects that need to be completed before additional development can occur in the East Zumbro sewer shed to prevent potential residential sanitary sewer back-ups. This project is also the first phase of the East Zumbro improvements included in the approved State Bonding proposal.

The project includes upsizing the sanitary sewer along 7th St NE to 11th Ave NE. This upgrade will enable all sanitary work in the Silver Lake Park area, related to the East Zumbro sewer shed, to be completed concurrently with other Silver Lake projects, thereby minimizing future disruptions in the park. The intersection of 7th St NE and 11th Ave NE has been improved to a roundabout design to remove one of the older traffic lights in the City and to improve traffic and pedestrian movements in the intersection.

The project has been timed to occur with the Silver Lake dam modification project and was delay for a year to accommodate the Silver Lake bid changes. The roundabout was not include in the original proposal and was determined during the design that it was a better option for the intersection and should be included in the project at this time to prevent a future impact to the intersection. The design required changes to trails, pedestrian facilities, watermain, storm sewer, and sanitary sewer connections. Additional state permits were also required for the watermain and storm sewer changes.

WHKS has submitted an amendment to the project to address the additional design of the roundabout and preparing plans for bidding. Amendment 1 is included in the Council packet. The amendment is a 12.5% increase to the original final design contract of $349,228.00.

This project is in alignment with the Council's Strategic Priority of Quality Services by executing infrastructure improvements that increase sanitary sewer capacity in advance of future growth to minimize the potential for sanitary sewer surges. The Sanitary Sewer Master Plan identifies the sewers that need to be improved for additional development in the East Zumbro sewer shed.

This project is also part of the East Zumbro improvements outlined in this years bonding approval and federal grant approval.

The project details and construction impacts was included in the July 2025 public open house where the proposed Silver Lake Dam Modification and Sediment Removal project and various ongoing Silver Lake Park improvement projects were discussed.

January 23, 2019: Council Meeting- Preliminary design services approved.

June 1, 2020: Council Meeting - Sanitary Sewer Master plan approved.

February 3, 2025: Council Meeting- Final design service with WHKS approved.

July 17, 2025: Public Informational Meeting for Silver Lake Park and surrounding area projects.

July 28, 2025: Council Study Session - Included in Silver Lake Sediment Removal and Dam Modification update.

The project was in the 2022-2027 Sewer and Water Capital Improvement Plan (CIP) as Map No. 8 and in the current 2026-2031 Sewer and Water CIP as Map No. 6. and is funded by the Sewer Utility, and RPU Water, Stormwater Utility, and Streets for the roundabout improvement.

No alternative actions are suggested at this time.