State Water Resources Research Institute Program
Project ID: 2007IL160B
Title: Balancing Irrigation and Instream Water Requirements under Drought Conditions: A Study of the Kanakee River Watershed
Project Type: Research
Start Date: 3/01/2007
End Date: 2/28/2009
Congressional District: 15
Focus Categories: Drought, Irrigation, Groundwater
Principal Investigators: Cai, ximing (University of Illinois at Urbana-Champaign); Lin, Yu-Feng (University of Illinois at Urbana-Champaign & Illinois State Water Survey); Valocchi, Albert Joseph
Federal Funds: $ 19,480
Non-Federal Matching Funds: $ 49,815
Abstract: Research Problem: Groundwater is the major source of water for more than 12,000 acres currently irrigated in the Kankakee River watershed, Illinois. During low flows in dry years such as the 1987-1988 drought, there are increased instream flow concerns about issues such as potential endangerment to fish and recreation, an irreplaceable amenity in the area. Given the potential increase of irrigation and other water demands, the marginal status of riverine ecosystems and conflicts between irrigation and in-stream uses may intensify in the future with a risk of reduced groundwater storage, stream depletion and ecosystem degradation and agricultural production loss. This project aims to improve understanding of the connection between irrigation water use and low flows and search for the development of a strategy to balance the two requirements under drought conditions.
Objectives: The traditional safe yield concept based on the natural recharge rate but ignoring the requirement of natural groundwater discharge for maintaining the environment quality has led to the degradation of the natural discharge areas of groundwater systems in many parts of the world. A proper groundwater use policy that takes into account natural discharge needs to be developed based upon our understanding of the coupled hydrogeological-human system, and upon an explicit recognition of the inherent uncertainty associated with modeling this system. This project is based on the hypothesis that the development of a proper groundwater use policy requires quantifying the uncertainties of stream-aquifer interaction zones caused by spatial variability of both hydrogeological properties and human interferences. To test this hypothesis, this project targets the following objectives:
(1) Explore the spatial variability of stream-aquifer interactions at a regional scale; and establish and calibrate a numerical model of the Kankakee watershed based on the understanding of the spatial variability of hydrogeology and human interference through pumping
(2) Understand how model uncertainty affects tradeoffs between irrigated agriculture and instream low flow requirements, and determine the implications of this uncertainty upon groundwater pumping management policies
Methodology: A systems approach to groundwater and surface water interactions will be developed to characterize the complex impacts of human activities upon the hydrologic cycle. Specific tasks include: 1) model establishment and hydrogeologic uncertainty treatment; 2) assessment of biased error in groundwater pumping rates, which imposes a significant challenge to model calibration and further use of the model as a prediction tool; 3) model calibration through an integrated program to analyze white noise along with biased pumpage input errors; 4) pumping plan screening; and 5) probability-based tradeoff analysis and recommendations for policy making.
Results and Benefits: This project attempts to translate state-of-art scientific research into reliable information so as to increase public and government acceptance of the environmental impact of irrigation development in the Kankakee watershed. The government and stakeholders will then benefit through a process which informs their planning and management practices for a win-win solution, sustaining human water uses and reducing the risk of riverine ecosystem degradation. The modeling simulation and extended analysis for watershed management can be adapted to other watersheds in Illinois which have conditions similar to the Kankakee. We also expect to make methodological contributions through our development of a process to assess errors in human input and the impacts on hydrologic modeling and prediction.
Progress/Completion Report, 2007 PDF
Progress/Completion Report, 2008 update, PDF