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Home My WebLink About07-08-25 Agenda Packet Chair: Joel Gerich (2027) Secretary: Linda Hansohn (2026) Board Members: Gary Gerding (2028) Kent Stennes (2026) Melissa Jannakos (2027) Linda Hansohn (2026) Joel Gerich (2027) Andrew Elmquist (2027) Open seat (2028) Staff Liaison: David Swearingen Karth Lake Improvement District Board REGULAR MEETING Tuesday July 8, 2025 1245 W. Highway 96 Arden Hills, MN 55112 651.792.7800 www.cityofardenhills.org Agenda Board Meeting Convenes at 6:30 PM CALL TO ORDER/ROLL CALL Kent Stennes notified the Board that he will be absent 1. APPROVAL OF THE AGENDA 2. APPROVAL OF MINUTES of the previous meeting April 8, 2025 3. PUBLIC INQUIRIES 4. OLD BUSINESS 4.1. Lakeshore owner outreach and education. Joel Gerich 4.1.1. Background: The KLIDB has reached out to KLID members in the past with flyers, events and door-knocking to increase awareness of what the KLIDB does, provide information to assist members in managing their shoreline and to recruit new board members. The Board agreed to consider another Ice Cream Social for Summer 2025. 4.1.2. Action: At the April meeting the Board voted to have the Ice Cream Social on June 24 but scheduling and communication issues meant that information was not going to be available in a timely manner so it seemed unlikely that there would be reasonable attendance. Joel has suggested a reschedule date of July 29. 4.2. Water quality monitoring for Karth Lake for 2025. Gary Gerding 4.2.1. Background: The KLIDB has participated in the Citizen-Assisted Monitoring Program (CAMP) with the Metropolitan Council by coordinating volunteer sampling of Karth Lake’s water quality since 2006. 4.2.2. Action: Provide any updates for 2025 sampling program. 5. NEW BUSINESS 5.1. Possible outreach to attract another Board member 5.2. Discuss garden maintenance for the garden bed within Cummings Park. David Swearingen 5.3. Discuss pump proposal and Geocell information for the Cummings Park retaining wall as part of the 2026 PMP project. David Swearingen and Brad Fisher (Audio call so timing of Brad’s call may determine when this item occurs) 5.4. 2025 Purple loosestrife assessment 6. NEXT MEETING October 14, 2025 7. ADJOURN Draft Minutes for Karth Lake Improvement District Board Regular Meeting 6:30 PM, Tuesday, April 8, 2025 CALL TO ORDER/ROLL CALL The meeting convened at: 6:30 PM. Present: Board Members: Susan Johnson, Chair, Linda Hansohn, Secretary; Kent Stennes; Gary Gerding; Andrew Elmquist; Joel Gerich Staff Liaison: David Swearingen, Public Works Director Visitors and Karth Lake Improvement District members: Renee Marino, Jim Elliot Absent: Melissa Jannakos 1. APPROVAL OF AGENDA: The agenda was approved 2. APPROVAL OF MINUTES: The minutes of the previous meeting on January 28,2025, were approved. 3. PUBLIC INQUIRIES: None. 4. OLD BUSINESS 4.1. Lakeshore owner outreach and education. Kent Stennes. 4.1.1. Background: The KLIDB has reached out to KLID members in the past with flyers, events and door-knocking to increase awareness of what the KLIDB does, provide information to assist members in managing their shoreline and to recruit new board members. 4.1.2. Discussion: The Board set Tuesday June 24 6:30-8:00 for the Ice Cream Social. Joel has volunteered to coordinate the event and will check on the availability of the shelter. Flyers will be sent to folks on the lake. 4.2. Karth Lake water level modeling and management process progress report. Renée Marino 4.2.1. Background: Hypothesis: a revision to the pump management policy can reduce water level bounce (i.e., range of high and low levels), which can improve lake quality and its environment while appropriately mitigating risk of damage to shoreline properties. 4.2.2. Discussion: The subcommittee met and prepared a presentation to bring to the City Council. This was reviewed by Matt Kocian of Rice Creek Watershed and David Swearington. There was an extensive conversation to understand how this will be part of the PNP street improvement project. David mentioned that a survey was sent to all the property owners impacted by the 2026 project. 4.2.3. Action: This presentation should be completed by May 7 and presented to council at their work session on May 12. Presenters will be Kent, Joel and Renee. 4.3. Water quality and impact of feeding migratory waterfowl as well as purple loosestrife mitigation 4.3.1. Background: Some people have been feeding geese and crows and this has been impacting water quality in the lake. A presentation was made to city council to tighten wording for restrictions for feeding migratory waterfowl. Susan talked to the DNR about purple loosestrife removal. If it is not submerged, no permit is required. If it is in the water, we need a permit to remove it. 4.3.2. Action: David will check with the council to see what is happening. Susan will submit a request to the DNR for the permit to remove Purple Lossestrife. 4.4. Status of log removal by DNR gauge 4.4.1. Background: There are some logs by the DNR gauge in the lake that have moved the gauge and need to be removed. The logs have been cut and the DNR gauge reset. The logs could not be removed because they were still frozen in the ground. 4.4.2. Action: David’s team will need to remove the cut up logs as well as a discarded hockey net that is down there. The DNR has moved the gauge. 5. NEW BUSINESS 5.1. Board member and officer elections 5.1.1. Terms expire for Gary Gerding and Susan Johnson Susan is not continuing her membership on the Board. Gary is willing to continue participating and was voted in for another term until we have anyone interested. We will have one empty seat. 5.1.2. Election of Chair and Secretary Joel was nominated/elected to be Chair Linda was elected to be Secretary 5.2. Water quality monitoring for Karth Lake for 2025. Gary Gerding 5.2.1. Background: The KLIDB has participated in the Community-Assisted Monitoring Program (CAMP) with the Metropolitan Council by coordinating volunteer sampling of Karth Lake’s water quality since 2006. 5.2.2. Action: There is no data available for 2025 yet. 6. NEXT MEETING: Tuesday July 8, 2025, at 6:30 PM at City Hall. 7. ADJOURN Page 1 of 3 Memorandum (DRAFT) Date: May 7, 2025 To : Honorable Mayor and City Councilmembers Jessica Jagoe, Interim City Administrator From: The Karth Lake Improvement District Board, in coordination with the Rice Creek Watershed District Subject: Karth Lake Level Modeling Project as Pertains to the 2026 PMP Street and Utility Improvement Project The Project: The KLID board initiated a Karth Lake Level Modeling Project in October 2021.1 Purpose: Explore modification to the current lake level pumping plan with the goal of reducing Karth Lake’s extreme high and low lake levels (“bounce”) of 3-5 feet. A reduction in bounce is expected to reduce erosion, improve water quality and improve the health of fish, vegetation and wildlife in and around the lake, as well as discourage expansion of invasive plant species. History: Beginning in the 1970s, land use surrounding Karth Lake began transitioning from agricultural to residential and business use. Surface water management, including installation of street sewers with outlets into Karth Lake, caused a near quadrupling of the watershed: from 41 to 143 acres. These include about 25 acres of impervious surfaces, more than the lake’s normal surface area of 20 acres.2 Karth Lake has no natural outlet and is assigned to the RCWD even though it does not naturally drain into Rice Creek. Since development around the lake began, periods of Karth Lake flooding have occurred and been managed by the City using contractors to temporarily pump water into street sewer systems to the north or west that drain into Rice Creek. Known incidences of temporary pumping occurred in 1984, 1986 and 2002. In 2003, the City retained a hydrology firm, URS, to propose a permanent pumping and maintenance plan for Karth Lake. The City submitted URS’ report to the DNR in support of DNR permit #2003-3078. That permit allowed construction of a permanent pumping facility and adopted URS’ proposed parameters for operating the pump (the DNR Pumping 1 Contributors to the Project include the Karth Lake Improvement District Board (KLIDB), City of Arden Hills (City), Minnesota Department of Natural Resources (DNR), Rice Creek Watershed District (RCWD) and Houstin Engineering (HE). HE is a hydrology consulting firm retained by RCWD to assist with the Project under a Minnesota Pollution Control Agency (MPCA) Stormwater, Wastewater, and Community Resiliency grant. 2 These impervious surfaces cause a nearly immediate lake level rise of 2.25 inches for every 1.0 inch of rain. During periods of frequent and quick rains, run-off from the rest of the watershed can cause the lake level to rise by as much as a 4:1 multiple of rainfall. Page 2 of 3 Strategy): start pumping when the lake reaches an elevation of 936 feet above sea level (or 935 in the fall) and continue pumping until it drops 2 feet to 934. Implementation challenges of the DNR Pumping Strategy have occurred when the pump has underperformed, failed, and/or suffered vandalism to both the floating pump platform and control panel. Since 2003, the lake has dropped to at least 933 3 in drought conditions and risen to 937 during mechanical difficulties. This lake level bounce of 4 feet since 2003 has contributed to significant shoreline erosion, fish kills, challenges to water quality, and infestation of invasive weeds such as purple loosestrife. City/DNR records indicate that a total of 651 days of pumping have occurred in the 40 years since 1984. The Karth Lake Level Model discussed below implies that this pumping has cumulatively lowered the lake’s level by 36 feet. Since Karth Lake’s normal level of around 935 feet above sea level is only about 10 feet below the lowest point of Amble Drive (946 feet), pumping has been an essential component of flood mitigation within the watershed. The Project ‘s Details and Recommendations: HE developed an initial Karth Lake Level Model to project pump impact on lake level over a one-month period following a single rain event. That model utilized external data on topography, evaporation, pump specs, etc. A KLIDB member expanded the model to accommodate a year’s worth of daily inputs (such as daily precipitation data collected from the nearest measurement stations by the State of Minnesota) and other enhancements. Those enhancements were made under the direction and review by HE and RCWD. An essential facilitator for this effort has been the collection of data: The DNR installed a lake gauge in the spring of 2022 and volunteers have made weekly and sometimes daily readings which are available to the public on the DNR LakeFinder website. The model was calibrated and validated with data collected from 2022 through 2024. Lake levels were then modeled using alternative pumping parameters by applying 60 years of actual daily rain data under the assumption they would fall on Karth Lake’s current watershed. The findings are startling: • Without pumping, Karth Lake would periodically overflow onto Amble Drive, flooding at least half of the houses on the lakeshore and spreading to off-lake houses in the watershed. The historical pumping of a cumulative 37 feet from the lake level supports this finding. 3 When the lake is at 934, the bottom of the original lake level gauge is exposed sand. Before the DNR gauge was installed in May 2022, only a few measurements below 934 exist, including a 2011 Minnesota State LIDAR flight measurement of 933. Page 3 of 3 • As such, pumping is an essential component of the City’s surface water management responsibilities within the entire watershed. It is not merely a means to protect the lowest-lying properties or to enhance the aesthetics of lakeshore properties. • The DNR Pumping Strategy can be improved upon. KLIDB recommends an alternative pumping strategy (Proposed Strategy) of starting to pump sooner, at 935.5, and only removing half a foot at a time by turning the pump off at 935.0. This strategy is superior to the DNR Pumping Strategy on nearly all metrics (reduced bounce, higher average levels). The Proposed Strategy would require pumping in 81% of all years versus 75% for the DNR Pumping Strategy but pump for 2.5% fewer days, thereby extending the expected life of pumping equipment. Recommendation for Implementation: The City’s lake level management process should be modernized to reduce the current labor-intensive pumping and monitoring process. Digital monitoring and remote pump activation would allow better control of lake level fluctuations.4 The upcoming City’s 2026 PMP Street and Utility Improvements project (2026 PMP) provides an opportunity to include funding for a new fixed pump and automated controls housed in a vandal resistant pump house. A cinder block pump house could also serve as the retaining wall replacement item planned within the 2026 PMP and may cost less than a landscape block type of retaining wall. Climate change and any future development that expands impervious surfaces within the watershed increase the likelihood of flooding should a back-up pump be unavailable. The existing floating pump could be a back-up should a new primary pump need repairs. Since the pumping of Karth lake is an essential component of surface water management and flood control for the entire watershed, the cost of improvements to the pumping infrastructure is more appropriately borne by owners of all properties within the watershed, not merely owners of lakeshore property. The Karth Lake Improvement District Board supports the feasibility and design objectives initiated by the City and described in the Bolten & Menk, Inc. 2026 PMP study regarding storm sewer pumping improvements and retaining wall replacement design.5 KLIDB also urges a solution that is consistent with a long term vision for the health and functionality of the Karth Lake watershed. 4 Methods for automated lake level measurement are relatively inexpensive. The DNR has extensive experience with this and is ready to be a resource for the City’s planners. Further, equipment to remotely monitor and control the existing and potential new pump is available. 5 Pp. 11-12 of Exhibit A to 2026 PMP Street and Utility Improvements, City of Arden Hills. 2026 PMP Street & Utility Improvements Karth Lake Improvement District Board Meeting July 8, 2025 Proposed Improvements 2 •Retaining Wall Replacement (Base) •Consideration for Geoweb Slope Stabilization •Pump System Improvement Options (Alternate) •Lake Level Monitoring •Potential Pump Automation Summary of Preliminary Estimated Costs •Option 1 – Karth Lake Pump System Improvements •$14,000 for Water Level Logging Device added to Existing Deployable Pump •Option 2 – Karth Lake Pump System Improvements •$112,000 for New Culvert Connected Structure to Place Existing Pumps In w/ Water Level Logging Device & Potential Pump Automation Improvements •Option 3 – Karth Lake Pump System Improvements •$500,000+ for Full Lift Station Type Design 3 Project Schedule & Next Steps •April – July 2025: Data Collection & Feasibility Study •July 14, 2025: City Council orders Public Improvement Hearing •July 28, 2025: City Council conducts Public Improvement Hearing, Considers Ordering Preparation of Final Plans & Specifications •September 2025 – January 2026: Final design & plan production •January – February 2026: Bidding by contractors •February 2026: City Council receives bids, orders public assessment hearing •March 2026: City Council conducts Public Assessment Hearing, considers levying special assessments, considers contract award •Spring 2026: Construction Begins 4