REPORTS ON THE WALNUT CREEK WATERSHED MONITORING PROJECT, JASPER COUNTY, IOWA 
 WATER YEARS 1995-2000

K.E. Schilling, J.L. Boekhoff, T. Hubbard, and J. Luzier

Iowa Department of Natural Resources, Geological Survey Bureau
Technical Information Series 46, 2002, 75 p.

INTRODUCTION


This report on the Walnut Creek Watershed Restoration and Water-Quality Monitoring Project consists of a series of articles that summarize the results of monitoring activities in Walnut and Squaw creek watersheds in Jasper County for water years 1995 to 2000.  (A water year is a 12-month period, from October 1 through September 30, designated by the calendar year in which it ends.)  As discussed in the introductory article of this report, the Walnut Creek project was established in 1995 to monitor the effects of large-scale prairie restoration occurring at the Neal Smith National Wildlife Refuge on water quality in the Walnut Creek watershed. 

This report is the third comprehensive report prepared for the Walnut Creek project.  In 1999, a summary report was published which reported on results from the first three years of monitoring (water years 1995 to 1997), including land use, discharge and suspended sediment, surface and groundwater quality, and biological monitoring (Schilling and Thompson, 1999).  In 2000, results of discharge and suspended sediment monitoring in Walnut and Squaw creek watersheds for water years 1995 to 1998 were examined in detail (Schilling, 2000).  Unlike previous reports, this compendium is organized as a series of articles in order to present more discussion associated with individual project components and make individual topics more accessible for viewing on the Iowa Department of Natural Resources, Geological Survey Bureau web page (www.igsb.uiowa.edu). 

Following an introductory article describing the project background and land use changes, other articles in this report focus on specific aspects of surface water quality monitoring, including:

         Nitrate, chloride and sulfate concentrations and loads,

         Herbicide concentrations and loads,

         Fecal coliform concentrations,

         Common field parameters of pH, specific conductance, turbidity, etc.,

         Biological monitoring of macroinvertebrates and fish.

Discharge and suspended sediment data were not presented in this report.  This information will be included in a later report in conjunction with presentation of a sediment erosion and delivery model for the Walnut and Squaw creek watersheds.

We hope that the monitoring topics discussed in this report are of interest to those following the Walnut Creek project as well as those interested in water quality monitoring in the State of Iowa.  Lessons from this project, both positive and negative, offer valuable insight on strategies for monitoring watershed scale relationships between land use and water quality.   Improved understanding of these relationships moves us closer to being able to track the effectiveness of best management practices to reduce nonpoint source pollution. 

 

References

Schilling, K.E. and Thompson, C.A. 1999.  Walnut Creek nonpoint source monitoring project, Jasper County, Iowa: water years 1995-1997.  Iowa Department of Natural Resources, Geological Survey Bureau, 169 p.

Schilling, K.E.  2000.  Patterns of discharge and suspended sediment transport in the Walnut and Squaw creek watersheds, Jasper County, Iowa: water years 1996-1998.  Iowa Department of Natural Resources, Geological Survey Bureau, 47 p.