I would suggest people read this chapter of the City of Waukesha's diversion proposal (full application here) because it helps answer one oft-posed question: why would Waukesha go through a protracted application for Great Lakes water that will require the agreement of eight states, and then plunge into a problematic negotiation for the water supply from the City of Milwaukee?
Implementability. The City’s ability to implement Alternative 1, which requires the installation of 14 new shallow wells, would be difficult for several reasons.
First, Waukesha is part of a groundwater management area, and as a result, more requirements and restrictions could be placed on groundwater development. Additionally, groundwater protection legislation has been recently introduced (on March 12, 2010). The legislation would require environmental review of proposed high capacity wells located in a groundwater management area before WDNR approves or develops a groundwater management plan for the area.
Second, the shallow aquifer wellfield would be installed outside the City’s boundaries. Significant land purchase/lease and controls outside the city limits would be required. Residents near the shallow aquifer wellfield have opposed high-capacity wells because of concerns about adequate water supply and impacts to wetlands, private wells, and other environmental resources.
Installation of wells in the unconfined aquifer may create legal challenges and expose the City to numerous damage claims from lake area homeowners and municipalities and would be a source of continuing controversy in the region. The City, for example, could be liable if its withdrawal of water causes unreasonable harm through lowering the water table for residential and municipal wells in the area. The City could also be liable if its withdrawal of groundwater had a direct and substantial effect upon the water of a watercourse or lake (i.e., effects to base flow or lake levels).
If new wells need to be installed in the future because of declining water levels in existing wells or the need to locate wells farther from surface water resources, wells may need to be located a greater distance from Waukesha. Locating wells further from Waukesha would increase costs, energy usage, and legal/public concerns. The environmental and legal impacts described above would become more severe.