Evaluation of Groundwater & Surface-Water Interaction

SUMMARY

The Metropolitan Council, in conjunction with Barr Engineering Company consultants, undertook a study to examine the relationship between groundwater and surface waters in the Twin Cities metropolitan area.

Surface water features, and the natural and recreational resources that they support, are a recognized asset to the region. The hydraulic connection between the region’s surface water and groundwater systems makes our lakes, streams, and wetlands vulnerable to increasing groundwater withdrawals for growing urban demand.

In development of the 2010 Twin Cities Metropolitan Area Master Water Supply Plan, the Metropolitan Council identified the need for a screening method to identify areas where groundwater withdrawals were most likely to have an impact on surface waters. In these areas, further characterization of the groundwater-surface water connection may be an important part of local water supply development. Initial screening methods indicated several areas with potential for groundwater pumping to impact surface water features. This study was conducted to: (1) prioritize surface water features for impact monitoring and resource assessment and (2) recommend monitoring and analysis techniques that will provide early warning to water supply managers to help avoid impacts on surface water features from groundwater pumping.

This information and the tools generated through this project are intended to support water appropriation permitting, sub-regional water supply management plan development, re-calibration of the Metropolitan Council’s regional groundwater flow model (Metro Model 2), and future updates of the Twin Cities Metropolitan Area Master Water Supply Plan.

DELIVERABLES

• Report: Evaluation of Groundwater and Surface-Water Interaction: Guidance for Resource Assessment (PDF, 373 KB)
• Geodatabase: Evaluation of Groundwater and Surface-Water Interaction: Guidance for Resource Assessment (ZIP, 441 MB)
• Guidance: Generalized monitoring strategy – designated trout stream (PDF, 687 KB)
• Guidance: Generalized monitoring strategy – calcareous fen (PDF, 623 KB)
• Guidance: Generalized monitoring strategy – lake/wetland discharging to groundwater (PDF, 500 KB)
• Guidance: Generalized monitoring strategy – stream discharging to groundwater (PDF, 377 KB)
• Guidance: Generalized monitoring strategy – lake/wetland fed by groundwater (PDF, 171 KB)
• Guidance: Generalized monitoring strategy – stream fed by groundwater (PDF, 464 KB)
• Guidance: Generalized monitoring strategy –flow-through lake/wetland (PDF,548 KB)
• Guidance: Generalized monitoring strategy – karst spring (PDF, 594 KB)

OUTCOMES

• Water appropriation permitting, sub-regional water supply assessments, regional modeling are better informed about the impact of groundwater pumping on connected surface water features