Council approves Part 1 of West Metro multi‑community wellhead protection plan; agrees to continued regional participation

The Eden Prairie City Council on April 15 approved Part 1 of a West Metro multi‑community wellhead protection plan and adopted a resolution to continue participating in development and implementation of Part 2. Robert Ellis, Public Works director, presented the plan and said it is the first multi‑community effort of its kind in Minnesota.

Ellis said Part 1 comprises: (1) a regional hydrogeologic and groundwater‑flow model, (2) delineation of drinking water supply management areas (DWSMAs) using a 10‑year horizontal time‑of‑travel standard, and (3) a vulnerability assessment that evaluates vertical travel time from surface to aquifer. The presentation used updated hydrogeologic data from the Hennepin County geologic atlas, Minnesota Department of Health (MDH), U.S. Geological Survey and historical well logs to model groundwater flow across municipal boundaries.

Ellis described why a regional approach was necessary: previous plans (the city’s last update was 2013) had delineated DWSMAs that extended outside city limits, limiting city authority to act on sources beyond Eden Prairie’s boundaries. The multi‑city effort includes Eden Prairie, Chanhassen, Minnetonka, Hopkins, St. Louis Park, Richfield, Edina and Bloomington and has MDH and Met Council support. Ellis said the group secured a state clean water grant to fund the consulting work; he said the grant covers consultant costs so participating cities’ direct costs should be limited to staff time.

On technical findings, Ellis said the city’s public wells (16 wells were shown on the maps in the packet) draw from the Prairie du Chien‑Jordan aquifer. The modeling produced a one‑year horizontal time‑of‑travel emergency response area and a larger 10‑year DWSMA that, in the updated map, extends north toward Lake Minnetonka. The vulnerability assessment maps vertical travel times: areas classified “very high/high” may transmit surface contaminants to the aquifer in hours to years, “medium” in years to decades, and “low/very low” in decades to more than a century. Ellis noted that much of Eden Prairie falls into medium vulnerability, reflecting improved data and the potential for land‑use practices to affect groundwater over time.

Council members asked clarifying questions about private wells, observation wells, seasonal aquifer-level changes and available records. Ellis said the state and county maintain well permit records and that cities have access to those datasets; he also said observation wells show summer drawdowns of roughly 30–50 feet that recharge in wetter months. Council asked whether the clean water grant was secure; Ellis said the grant is state funding and not frozen.

The council voted to approve Part 1 and to adopt the accompanying resolution to continue participation in Part 2. The resolution, included in the council packet, authorizes the city to participate in the next phase: development of a contaminant source inventory (historical dump sites, underground storage tanks, abandoned wells), management strategy discussions, and contingency planning (treatment options or interconnection contingencies) should a contamination event occur.

Ellis summarized next steps: (a) finalize contaminant source inventories across the shared DWSMA, (b) develop proposed management strategies (owner outreach, well sealing, spill prevention), and (c) draft contingency plans and interconnection options. He said Part 2 work is grant‑funded and will require city staff participation rather than direct consulting costs from the city.

The council’s action was unanimous; the motion and second were made on the record and members approved by voice vote.