Care & Feeding of Aquifers

Dr. Jack Wittman, hydrologist and drought planner, says that you start tackling water supply issues by answering a couple of simple questions:

  • How much water do we need?
  • How much water do we have?
  • It’s an exercise in budgeting, really, yet we have not answered these questions–and we have the water authority referendum (covering most of DeKalb, Boone and McHenry counties) to vote on next month. Is the Kishwaukee Valley Water Authority (KVWA) the right way to respond to planning and management needs? In order to make a recommendation one way or the other to the DeKalb County Board, its Planning & Zoning Committee last night hosted an informational panel on water supply issues that included Dr. Wittman along with Dr. Colin Booth, a hydrogeologist from NIU.

    Dr. Wittman didn’t delve far into the actual water authority question except to suggest that he’s seen good resource management done at the county level of government and he supports some sort of regional planning as well. Dr. Booth, impeccably academic, would not touch politics at all. Two attorneys on the panel and a few agenda-toting audience members provided advocacy for both sides. However, the stars of the two-hours-plus discussion definitely were the scientists with their educational presentations. Following are some of the issues brought out that should be factored into further deliberations.

    Deep and Shallow, Local and Distant, Large and Small

    Dr. Booth encouraged us to think of our aquifer system as laid out in layers of huge, interconnected bathtubs. They can be found at different levels, sizes, and materials except that an aquifer must, of course, be water permeable. Our area has glacial sand and gravel aquifers at 20-100 feet deep, shallow bedrock (dolomite) aquifers beneath those, then deep bedrock aquifers that can be reached at 500-1500 feet. Between the aquifers lie strata that hold no water, meaning your well digger had better know what s/he’s doing.

    Here are a few rules of “tub”:

  • Household and agricultural users use shallow aquifers, while municipalities with their high-capacity wells go very deep.
  • Shallow aquifers have less capacity than deeper aquifers and are more likely to hold local water. The deepest bedrock aquifers are huge and may contain ancient water from far away.
  • Deep bedrock waters are less likely to become contaminated by surface sources but may naturally contain harmful elements like arsenic or radium.
  • Aquifer water needs to be replenished in a process called recharging and we need to pay more attention to that process if we don’t want to interfere with it.
  • The City of DeKalb has very deep wells. At least one of them draws water with unacceptable amounts of radium so the city dilutes the glowing water with that from a shallower well, standard procedure for a city with that problem but for the most part municipalities are not in direct competition with their rural neighbors for water. How cities can really mess it up for the country cousins is by allowing too much development in local recharging areas, where the water needs to get into the ground to replenish the aquifer. Some of our recharging areas lie west and north of DeKalb, into other counties and another state or two, but at least one local shallow aquifer could be affected by residential development that is pushing DeKalb’s boundaries to the west. We don’t know yet. What we do know is that recharge areas need to be part of local comprehensive planning to ensure that by and large they remain farmland, wetlands or other types of green spaces.

    Where DeKalb is said to have “competition” is in sharing the deep bedrock aquifers with other cities that are drawing from same. But is that really competition? If we’re all using the same aquifers and the levels drop, we’re all sunk. Sounds like a job for a regional planning authority to me–perhaps the 11-county Regional Water Supply Planning Group for northeastern Illinois, which just got started on its tasks?

    What Kind of Drought?

    We must distinguish between a drought and a water shortage. A drought may or may not lead to a shortage, but is more likely if the water supply is already stressed. In coming years of growth, shortages may happen in the absence of drought if we’re careless.

    Before planning begins, we also have to select what type(s) of drought to plan for. There are four types: meteorological, agricultural, hydrological and socioeconomic. (If you want the fine print, the link will bring you to a good, quick overview.) The range of usage priorities and other management strategies we end up with are dependent on the sort of drought(s) we want to prepare for.

    Risk Management vs. Crisis Management

    An argument in favor of the water authority is its inherently proactive nature, which prefers managing risk rather than managing crises. Risk management means doing the studies, the tracking, the prioritizing, the planning, the enforcing. That is expensive–but managing a full-blown crisis costs much more.

    Future Growth in Water Usage

    This is where the proposed boundaries of this water authority fall apart in terms of practicality. An example of a well-run water authority was brought up, one of those in the Mahomet Aquifer Consortium, but it was pointed out that this authority was organized only to address irrigation issues. Dr. Wittman reported that predicted growth in water usage in the (not quite) three-county area covered by the referendum was quite disparate, with Boone County expecting 90% of its growth for agricultural purposes, McHenry’s at least half put into rural wells, and DeKalb’s primarily in municipal growth.

    KVWA boundaries do not follow aquifer boundaries, nor shared usage priorities.

    Who’s Got the Power?

    I have been unable to find reliable estimates of how many people KVWA would affect. I read one ballpark estimate based on the original, pre-ruling boundaries of 50,000. Judge Klein added 50,000 to whatever the number is by including DeKalb and Sycamore after the hearings. As described in my last post on the subject, “Water Law Needs Overhaul,” one appointed–or even elected–trustee per county is way too little representation on a body that can tax, condemn property and perhaps even maintain a “water police force” (though this is in dispute).

    _______________________________

    At the end of the presentations, the Planning and Zoning Committee voted 5-1 not to make any specific recommendation to the board regarding the authority referendum on the basis of its requiring more study, but did acknowledge the need for an ongoing commitment to protecting the water supply.

    _______________________________

    Links: So’s you can differentiate between hydrology and hydrogeology if you so desire.

    Also, Dr. Booth’s 2004 presentation, Glacial Aquifers of Northeastern Illinois.

    And here’s a link to an EPA-monitored project called aquifer storage and recovery (ASR). Communities that use surface water such as Lake Michigan are experimenting with injecting large aquifers with treated drinking water during periods of low flow (usage). The reserves are then drawn on during times of high flow such as lawn-watering season. Use of aquifers as reservoirs is very new. Questions need to be answered about how lake water and chlorine by-products affect aquifer formation, for example will arsenic be leached from the rock. Still, if it works such storage would probably be less susceptible to contamination than traditional reservoirs and certainly provide tremendous capacity.

    Leave a Reply