DNR hydrologist Jason Mekel told the Subcommittee on Minnesota Water Policy on Oct. 24 that extensive monitoring shows Strait River groundwater levels and summer stream flows have been generally stable and resilient, and that the river receives about 93–97% of its flow from groundwater.

"I can say with a high degree of confidence that the Strait River may be or probably is the most intensely monitored...aquifer system that we have in the state," said Jason Mekel, summarizing the department's April 2024 report and noting the monitoring network includes seven continuous stream gauges, 59 groundwater monitoring wells, two climate stations and multiple lake and wetland sites.

The Minnesota Pollution Control Agency presented separate nitrate results for the same watershed. Kevin Stroom of the MPCA summarized three multiyear river-monitoring datasets (2004–10, 2015–16 and 2020–22) and said nitrate concentrations increased between the first and second datasets and have remained elevated. Stroom and his slides showed the seasonal pattern (higher in winter, lower in midsummer) and reported peak concentrations at the Highway 71 monitoring site around 3.5 milligrams per liter in winter samples.

"An increase in river nitrate occurred correspondingly with increased row-crop agriculture," Stroom said, and the MPCA recommended additional groundwater nitrate monitoring and development of a groundwater flow model to better attribute sources and design management actions.

Representatives of irrigator organizations disputed the MPCA's emphasis on crop irrigation as the primary source. Dan Whitney, board member and technical adviser to the Irrigators Association of Minnesota and Central Minnesota Irrigator, said his group's early findings point to multiple potential contributors, including septic drain fields, riparian forest and wetlands, and wildlife: "The lack of consideration toward potential sources of nitrate to the river other than irrigated agriculture" was a concern, Whitney said, and he said his organizations will ask the MPCA to revise the report.

DNR staff emphasized limits in the available record: Mekel noted the monitoring period already includes substantial irrigation activity, so there is no clean pre‑irrigation baseline. He said the most useful next step for quantifying irrigation effects on streamflow would be a groundwater model similar to ones developed for Little Rock Creek and White Bear Lake; he noted a University of Minnesota model is under way but may not yet provide the resolution needed to quantify streamflow impacts.

Members of the committee asked technical and policy questions during the meeting and encouraged follow-up exchanges among agencies, irrigator groups and researchers. Several presenters and committee members said written questions should be routed through staff member Jim Stark for consolidation and distribution.

What changed: MPCA presented statistical evidence of higher nitrate in recent datasets and tied the rise in nitrate to increases in irrigated row crops; DNR reported stable aquifer levels and streamflow but recommended more modeling; irrigator groups said other nitrate sources deserve fuller analysis.

Next steps discussed included targeted groundwater nitrate monitoring in the subwatershed, development of a fine‑scale groundwater model to trace water and nitrate pathways, and continued stakeholder review of the MPCA report.

Ending: Committee staff asked attendees to submit follow‑up questions to Jim Stark; no formal policy decision or new rule was adopted at the Oct. 24 meeting.