Water Resources Management program
Iowa Geological and Water
Survey’s Role in the 2008 Water Resources Management program
The Iowa Geological and Water Survey (IGWS) plans and implements programs
that result in the acquisition of comprehensive information on the mineral
and water resources of Iowa, with emphasis on water supply developments and
monitoring the effects of environmental impacts on water quality.
(www.igsb.uiowa.edu/about/mission.htm)
Some of the most frequently asked questions of the IGWS are about
groundwater, and since groundwater supplies 80 percent of Iowans their
drinking water, an understanding of the geologic and hydrologic framework
that contains Iowa’s groundwater is in the best interest of Iowans and is
essential when planning for better and sustainable use, protection, and
management of Iowa’s most valuable natural resource.
The last comprehensive state water plan for Iowa was completed in 1978 by the Iowa Natural Resources Council (www.iowadnr.com/water/files/1978waterplan1.pdf). This plan was funded by the state legislature and took three years to complete. It addressed major water problems of the time and recommended policies and programs to solve and prevent current and future problems. While some portions of the plan were implemented, the plan did not provide a mechanism for ongoing water planning. Additional plans and programs have been developed since 1978, however, these efforts were never integrated into a comprehensive plan for water management and have not created the public awareness needed to prevent degradation of groundwater and surface water resources in Iowa. The last update of the state water plan occurred in 1985. (www.iowadnr.com/water/files/1985waterplan.pdf)
The ability to protect and improve Iowa’s natural resources, while utilizing them to benefit society, requires proactive long-range planning, based on accurate and current geologic and hydrologic information. In the past, most funding for water planning issues has come from the state general fund. However, continued reductions in general fund revenues and geologic and hydrologic staffing over the last 20 years have made it difficult for the IGWS to conduct the preemptive investigation and research necessary to create and maintain a forward looking, integrated, and comprehensive Water Resources Management program.
Recently, concerns about the availability of groundwater in Iowa have come to light because of increasing demand for large quantities of water from various industries, as well as increases in demand from agricultural, municipal, and domestic uses. While Iowa is probably not facing an immediate water shortage, we currently do not have the information or resources available at the state level to answer basic questions regarding how much water can be withdrawn from Iowa’s aquifers on a sustainable basis, without significantly lowering water levels and depleting very long-term groundwater storage.
Following a proposal in 2007 from the Iowa Geological and Water Survey for annual funding to characterize the availability, quality, use, and sustainability of Iowa’s surface water and groundwater resources, the Iowa legislature approved funding to support a comprehensive Water Resource Management program for Iowa (www.iaenvironment.org/documents/11-27-07FinalStateWaterPlan.pdf). Currently efforts are underway to secure sustainable funding for continued study and management of Iowa’s water resources through an improved water resource permitting system.
Iowa’s groundwater resources are stored in shallow unconsolidated aquifers
and in five deeper bedrock aquifers that are generally separated by
widespread confining beds, or aquitards, that slow the movement of water
between the aquifers (Figure 1). The unconsolidated aquifers include
alluvial sand and gravel deposits found along stream valleys and in ancient
buried river valleys, and sand and gravel deposits found within glacial
drift. The bedrock aquifers are usually sandstone, siltstone, limestone, or
dolomite, and sometimes are a combination of all of these rock types. The
major bedrock aquifers in Iowa were deposited between 75 to 550 million
years ago (mya), and include, from shallow to deep: the Cretaceous (Dakota),
Mississippian, Silurian-Devonian, Cambrian-Ordovician (Jordan), and Dresbach
(Mt. Simon).
The Major Aquifers to be Studied The Dakota Aquifer is the first major aquifer to be studied by Iowa Geological
and Water Survey under
the auspices of the 2008 Water Resources Management program. The study is part of the work in
progress to delineate the occurrence, movement, availability, use, and
chemical quality of groundwater from Iowa’s major aquifers for better and
sustainable management of Iowa’s groundwater resources. In the future, the IGWS will also be evaluating and updating information for the Mississippian,
Silurian-Devonian, and Cambiran-Ordovician bedrock aquifers, and possibly
some of the larger alluvial aquifers in Iowa as time and funding allow. As
more wells are completed in these aquifers and more stratigraphic,
construction, and water-quality data are interpreted and entered into our
databases, our knowledge of these valuable resources will improve and our
evaluation of them will be refined.
Our website materials for the 2008 Water Resources Management program are currently under
development and will also be improved and refined as more water resource
information is collected and interpreted.
Major Aquifer Studies (click to access)
Figure 1. Cross-sectional view of Iowa’s major aquifers and aquitards from
northwest to southeast (modified from Iowa’s Groundwater Basics by Jean C.
Prior, et al., 2003, Iowa Dept. of Natural Resources,
Iowa Geological Survey
Educational Series 6, 83 pages).