Organization | • | Illinois State Water Survey | [X] |
| | | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | A primary concern in the management of the Lower Cache River is the amount of sediment that is deposited in the river's valley in the vicinity of Buttonland Swamp. From previous monitoring studies it is known that floodwaters from Big Creek convey a significant amount of sediment and create a reverse flow condition in the Cache River that carries the sediment into Buttonland Swamp. This study investigated the potential influence of several management alternatives in reducing or eliminating the reverse flow condition in the Cache River, which would alleviate much of the sediment concern. Management alternatives include various options for detention storage in the Big Creek watershed as well as redirecting the lower portion of Big Creek to the west, away from Buttonland Swamp. To evaluate the impact of these alternatives, the hydrology of the Big Creek watershed and its influence on the hydraulics of the Lower Cache River were investigated using two models. The HEC-1 flood hydrology model was used to simulate the rainfall-runoff response of tributaries draining to the Lower Cache River, with emphasis on Big Creek and estimating the impact of detention storage on the Big Creek flood flows. The UNET unsteady flow routing model was then used to evaluate the flow patterns in the Lower Cache River and the impact of management alternatives on flow direction, flood discharge, and stage. Under existing conditions, the UNET model shows that reverse flow occurs in the Lower Cache River east of Big Creek confluence during all the flood events considered. Various detention alternatives in the Big Creek watershed have the potential to reduce the peak of the reverse flow by 26 to 76 percent. Of the detention alternatives examined, the larger detention facilities in the lower reaches of Big Creek appear to produce the greatest reduction in reverse flows. An alternative to divert the lower portion of Big Creek has the potential to totally eliminate reverse flows in the area immediately east of the Big Creek confluence with the Lower Cache River, but may cause increased flooding to the west. To eliminate most of the reverse flow east of Big Creek, and at the same time not increase flood stages farther west on the Lower Cache River, it may be necessary to use a combination of detention storage and either a partial or total diversion of the lower portion of Big Creek. For example, the use of the split flow alternative in combination with the many ponds and Cache valley detention alternatives reduces the peak reverse flows east of Big Creek by 81 percent for a 2-year flood and 92 percent for a 100-year flood. This combined alternative also accomplishes a reduction in the peak stages farther downstream west of Interstate 57 by approximately 0.5 foot. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-06 | | | | ISL ID: | 000000000836 Original UID: 999999994317 FIRST WORD: Hydrology | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | This report is the second of a series of three reports being prepared for the work done on the Kankakee River based on a Conservation 2000 Grant from the Illinois Department of Natural Resources. The present report focuses on the bank erosion mapping of the main stem of the Kankakee River from Route 30 Bridge in Indiana to the mouth of the Kankakee River with the Illinois River near Wilmington. A total of 111.8 river miles were mapped during a boat trip November 19-December 1, 1998. The relative magnitude of erosion was based on a visual assessment of the river banks during a boat trip along the main stem of the river. No actual measurements were taken. However, the extent of erosion was noted on 7.5-minute quadrangle maps based on visual observations. A series of 27 maps has been developed in which bank erosion identified on both sides of the river ranged form minor to high erosion. This analysis has shown the 10.4 river bank miles had severe erosion, 39.4 bank miles had moderate erosion, 70.8 bank miles had minor erosion, 46.3 bank miles were stable, 46.7 river bank miles were artificially protected, and data on 10.0 bank miles could not be collected because snags, islands, etc. made the banks inaccessible. This is a first attempt to map existing bank erosion conditions of the main stem of the Kankakee River. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-01 | | | | ISL ID: | 000000000837 Original UID: 999999994320 FIRST WORD: Bank | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | Sedimentation detracts from the use of any water supply lake by reducing lake depth and volume, with a reduction of reserve water supply capacity and possible burying of intake structures. Sedimentation of a reservoir is a natural process that can be accelerated or slowed by human activities in the watershed. Lake Decatur is located in Macon County, northeast of Decatur, Illinois. The location of the dam is 39 49 28" north latitude and 88 57 30" west longitude in Section 22, T.16N., R.2W., Macon County, Illinois. The dam impounds the Sangamon River in the Sangamon River basin. The watershed is a portion of Hydrologic Unit 07130006 as defined by the U.S. Geological Survey. The lake was constructed in 1922 with a spillway level of 610 feet above mean sea level (feet-msl). In 1956, a set of hydraulic gates was installed on the original spillway to allow variable lake levels from 610 feet-msl to 615 feet-msl. The portion of the lake surveyed for the present study was Basin 6 located above Rea's Bridge Road. This basin of the lake is the headwater area of the main body of the lake. Lake Decatur has been surveyed to document sedimentation conditions eight times since 1930. Five of these survey efforts (1936, 1946, 1956, 1966, and 1983) were sufficiently detailed to be termed full lake sedimentation surveys. The present survey is not considered to be a full lake sedimentation survey. Sedimentation has reduced the basin capacity from 2,797 acre-feet (ac-ft) in 1922 to 1,451 ac-ft in 2000. The 2000 basin capacity was 48.1 percent of the 1922 potential basin capacity. For water supply purposes, these volumes convert to capacities of 911 million gallons in 1922 and 473 million gallons in 2000. Sedimentation rate analyses indicate a decline in annual sediment deposition rates from 35.4 ac-ft for the period 1922-1936 to 8.3 ac-ft annually from 1983-2000. The long-term average annual deposition rate for 1922-2000 was 17.3 ac-ft. Density analyses of the sediment samples indicate that the unit weight of sediment in the northern (upstream) portions of the lake is greater than the unit weight of sediment in the southern end of the lake. In general, coarser sediments are expected to be deposited in the upstream portion of a lake where the entrainment velocity of the stream is reduced to the much slower velocities of a lake environment. These coarser sediments tend to be denser when settled and are subject to drying and higher compaction rates as a result of more frequent drawdown exposure in the shallow water environment. As the remaining sediment load of the stream is transported through the lake, increasingly finer particle sizes and decreasing unit weight are observed. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-07 | | | | ISL ID: | 000000000838 Original UID: 999999994321 FIRST WORD: Sedimentation | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The City of Decatur operates a series of ten groundwater wells in DeWitt and Piatt Counties that serve as an emergency water supply in times of low surface water levels in Lake Decatur. The City of Decatur contracted with Layne-Geosciences, Inc. (LGI) to develop a computer model of the groundwater system to simulate the effects of pumpage on the Mahomet Aquifer and surrounding wells. The LGI model was completed in April 1999. In response to lowering lake levels, Decatur began pumping their wells in November 1999 for 84 days at daily rates from 3 million gallons a day (mgd) to 16 mgd. The Illinois State Water Survey (ISWS) reviewed and tested the LGI model against the known drawdown encountered during the 84 days of operation. The LGI model was found to be only marginally successful in reproducing the measured water levels. The largest error occurred in the Piatt County area where the model significantly overpredicted the drawdown. These errors were the result of several factors, including errors in the aquifer thickness map, calibration to data only within 5 miles of the wellfield, errors in the location of pumping wells, the use of general head boundaries throughout the model, and, most importantly, the absence of a hydraulic connection between the Mahomet Aquifer, the Glasford Aquifer, and the Sangamon River near Allerton Park. Additional data available in the ISWS well records, and new data provided by Decatur through Guillou and Associates, Inc., indicate a connection between the aquifer system and the Sangamon River. Adding this connection represents a change in the conceptual model of the flow system not included in the LGI model. When this connection was added, a much closer match between observed and calculated water levels was obtained. Future work should focus on developing a more complete understanding of the connections between the aquifer system and the Sangamon River. Those efforts should include a pump test of the Cisco wellfield with complete monitoring of the river and aquifers. Monitoring of water levels at selected locations should continue and expand. The groundwater flow model should be re-calibrated using the new data and the improved understanding of the flow system. The results of these activities can provide an improved assessment of the potential of the Decatur wellfield for future use. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-11 | | | | ISL ID: | 000000000839 Original UID: 999999994322 FIRST WORD: The | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | One of the main concerns was the ability to specify proper stage hydrographs at the downstream boundary of the Lower Illinois River for hydraulic design and analysis. We found that a unique stage-discharge rating relationship does not exist at the lower boundary of the Lower Illinois River at Grafton because of backwater effects from the Upper Mississippi River. Management options and results for managed storage and emergency activities need to be analyzed under more comprehensive design of flooding conditions. To improve the capability of UNET for modeling backwater effects for the Lower Illinois River, an extended model including Pool 26 of the Upper Mississippi River was developed. The downstream stations of the model are at the tail of Lock and Dam 25 and the Mel Price Lock and Dam pool, where stage readings are available. The model was calibrated with a 1979 flood and verified with a 1983 flood. Discharge and stage frequency analysis have also been performed for stations at Troy on Cuivre River, Lock and Dam 25 tail, Lock and Dam 26 pool, and Mel Price Lock and Dam on the Mississippi River. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-10 | | | | ISL ID: | 000000000840 Original UID: 999999994323 FIRST WORD: Management | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | This report summarizes the results of surveying conducted at the mouths of five deltas on Peoria Lake in 1999. The five deltas are at the mouths of Richland Creek, Partridge Creek, Blue Creek, Dickison Run, and Farm Creek. All surveying was done to include the planform of the deltas that existed in 1999. The 1999 planform of four of the five deltas except Dickison Run is different than the locations in 1902-1904. In order to estimate the volumes of deposited sediment between 1902-1904 and 1999, a grid was developed encompassing the aerial extent of the 1999 delta. Subsequently, computations determined the net volumetric accumulation of sediment within each grid for each delta: 2,683 acre-feet (Partridge Creek), 1,495 acre-feet (Blue Creek), 1,428 acre-feet (Richland Creek), 1,252 acre-feet (Farm Creek), and 338 acre-feet (Dickison Run). Relative values of the sediment accumulation could be quite misleading since most of these creeks have been altered over the last 100 years, the 1999 outlets are not at the same locations as those that existed in 1902-1904, and a significant amount of sand-and-gravel mining took place at several locations such as at Farm Creek. Still these values provide a significant contribution toward the understanding of the relative magnitudes of sediments being deposited at the mouths of these five deltas. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-08 | | | | ISL ID: | 000000000841 Original UID: 999999994324 FIRST WORD: Historical | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | This is the third and final report on the Kankakee River in Illinois supported by the Conservation 2000 Program of the Illinois Department of Natural Resources. For this project, the Illinois State Water Survey mapped the bank erosion of the main stem of the Kankakee River from the Route 30 bridge in Indiana to the mouth of the Kankakee River with the Illinois River near Wilmington, collected about 100 bed and bank material samples, resurveyed all the previously surveyed river cross sections, surveyed four sand bars, and analyzed all historical and new data. This research has shown that of 223.6 river bank miles (includes both sides of the river), about 10.4 river bank miles have severe erosion, 39.4 river bank miles have moderate erosion, 70.8 river bank miles have minor erosion, and the remainder are either protected or stabilized or data are not available. The median diameter of the bed materials varied from 0.27 millimeters (mm) to 0.52 mm. The median diameter of bank materials varied from 0.07 mm to 0.41 mm. Analyses of the long-term flows from six gaging stations in Illinois showed an increasing trend in flows through the 1960s with no discernible increase since that time. Cross-sectional analyses of the river from the Kankakee Dam to the State Line Bridge did show some trends. The river reach from the Kankakee Dam to Aroma Park called Six-Mile Pool has lost 13.4 percent of its capacity due to sediment deposition since 1980. Similarly, Momence Wetland also has lost about 10.2 percent of its capacity since 1980. The section of the river between Aroma Park and Singleton Ditch showed both scour and sediment deposition. In general areas close to Aroma Park exhibited sediment deposition and the middle reach experienced scour. The recurring sand bar at the State Line Bridge area contains about 8,500 cubic yards of additional sediment in 1999 than were measured in 1980. The volumetric measurement of three additional sand bars showed some changes since 1980. The river is accumulating sediments within Six-Mile Pool and Momence Wetland. The middle reach is in semi-equilibrium with some sediment accumulation at several areas. Several management alternatives, both in-channel and watershed-based also are included to assist in the reduction of sedimentation problems of the Kankakee River. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-09 | | | | ISL ID: | 000000000844 Original UID: 999999994327 FIRST WORD: River | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | As part of a study to estimate corn and soybean yields using satellite remote sensing techniques, biomass measurements, ground-level spectral measurements, and weather and energy flux measurements were taken at three locations in McLean County, Illinois. The locations were near Colfax, Lexington, and Stanford, Illinois. Plant samples and leaf area measurements were taken during the weeks of 12-17 June, 26-30 June, 10-14 July, 31 July-4 August, and 14-18 August 2000 in McLean County, Illinois. Corn plants were separated into leaf, stem, husk, and ear components, and soybean plants into leaf, stem, and pod components. The wet weights of the different plant parts were determined. To determine the plant dry biomass, the plant parts were dried in an oven until there was no weight change over two consecutive days. Leaf area for both corn and soybean canopies was measured using a LiCor-2000 instrument. Corn leaf area was also determined by manual measurements of leaf length and width. The smallest corn and soybean plants were at the Lexington location. The largest corn plants were at Colfax, and the largest soybean plants were at Stanford. The smaller plants at Lexington were a result of sandier soils containing less organic matter than the soils at either Stanford or Colfax. Although final yield was not measured as part of this sampling protocol, the size of the plants would indicate that Lexington should have the smallest corn and soybean yields, while the highest corn yields should have occurred at Colfax, and the highest soybean yields at Stanford. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-13 | | | | ISL ID: | 000000000845 Original UID: 999999994328 FIRST WORD: Remote | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | This report documents the progress that has been made to date on the Conservation Reserve Enhancement Program (CREP) monitoring project. The Illinois Department of Natural Resources (IDNR) through the CREP provides support for this project. This monitoring program collects hydrologic, sediment, and nutrient data for selected watersheds within the Illinois River watershed to assist in the evaluation of the effectiveness of the program. The Illinois River CREP is a new initiative by the State of Illinois and the United States Department of Agriculture to implement conservation practices in the Illinois River watershed over a 15-year period that improve water quality and habitat for wildlife. Monitoring programs were established for sediment and nutrients for two pairs of watersheds within the Illinois River basin to collect hydrologic, sediment, and nutrient data during the implementation phase of the project. The two pairs of watersheds are the Court and Haw Creek watersheds (Spoon River basin) and the Panther-Cox Creek watershed (Sangamon River basin). This report details the location, equipment, and installation techniques used at the five monitoring stations and associated raingages that were installed as part of the data collection effort for this project. Samples of the data collection format and frequency are presented and described. Stage, nutrient concentration, and suspended sediment concentrations for data collected through June 2000 are also presented as appendices. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-12 | | | | ISL ID: | 000000000846 Original UID: 999999994329 FIRST WORD: Sediment | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The Illinois Streamflow Assessment Model (ILSAM) is an analytical and information tool developed to predict the frequency of streamflows, and water use impacts on streamflows, for every stream in selected major watersheds in Illinois. The current version of ILSAM was developed to operate on a personal computer having a Microsoft Windows 95/98/2000/NT operating system. The model user can obtain streamflow frequency estimates for any location in the watershed by identifying the desired stream and location. The ILSAM has been developed for use with streams in five such watersheds: the Sangamon, Fox, Kaskaskia, Kankakee, and Little Wabash River. This report includes a description of the steps used to develop ILSAM for application to the Little Wabash River watershed, along with a description of the physical characteristics of the watershed, its surface water hydrology, and the factors that influence streamflow variability. The Little Wabash River watershed is located in the southeastern portion of Illinois and has a total area of approximately 3238 square miles. The river and its major tributaries provide the source of water supply for all of the major communities in the watershed, either through direct withdrawals from the river or from the storage of water in impounding reservoirs. Many of these communities were forced to undertake emergency measures to sustain their water supply from these sources during the major droughts of the early- and mid-1900s. Thus, an understanding of the frequency of low flows and drought flows is critical for assessing surface water availability and yields for these communities. Streamflow frequency predictions produced by the model are also useful for evaluating instream flow levels for the protection of aquatic habitat, providing streamflow estimates for water quality analyses and regulations, and classifying Illinois streams by their hydrologic character for use in watershed management. The hydrologic analyses used to develop the model include evaluating the flow frequency from all streamgage records in the Little Wabash River region, evaluating impacts to flow quantity from dams, water supply, and treated wastewaters, and developing regional equations to estimate flows at ungaged sites throughout the watershed. All streamflow frequency estimates produced by the model are representative of the long-term expected flow conditions of streams, reflecting hydrologic conditions over a base period of nearly 50 years (1952-1999). | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-14 | | | | ISL ID: | 000000000855 Original UID: 999999994330 FIRST WORD: Streamflow | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The Illinois State Water Survey (ISWS), under contract to the Imperial Valley Water Authority (IVWA), has operated a network of rain gauges in Mason and Tazewell Counties since August 1992. The ISWS also established a network of groundwater observation wells in the Mason-Tazewell area in 1994. These networks are located in the most heavily irrigated region of the state. The region's major source of water for irrigation, municipal, and domestic water supplies is groundwater pumped from thick sand-and-gravel deposits associated with the confluence of two major ancient river valleys, the Mississippi and the Mahomet-Teays. Relatively recent extreme weather events (e.g., the drought of 1988 and the great flood of 1993) resulted in large fluctuations in groundwater levels in the Imperial Valley area. The purpose of the rain gauge network and the groundwater observation well network is to collect long-term data to determine the rate of groundwater drawdown in dry periods and during the growing season, and the rate at which the aquifer recharges. This report presents data accumulated from the rain gauge and observation well networks since their inception through August 2000. Precipitation is recorded continuously at 20 rain gauges for each storm that traverses the Imperial Valley. Groundwater levels at the 13 observation wells are measured the first of each month. The database from these networks consists of eight years of precipitation data and six years of groundwater observations. At the beginning of groundwater observations in late 1994, the water levels were at their highest in the six years of observation. These high groundwater levels were the result of the very wet 1992-1995 period when annual precipitation was above the 30-year normals at both Havana and Mason City. From September 1995-August 1997, precipitation in the region was well below the 30-year normal followed by the 1997-1998 and 1998-1999 observation years with rainfall totals that were slightly above and slightly below normal, respectively. Groundwater levels in the observation wells reflected the multi-year rainfall patterns, showing a general downward trend during the dry years, a recovery in the wet 1997-1998 year, and a leveling off in 1998-1999. Precipitation in the region during observation year 1999-2000 was well below normal, mirroring the quite low totals observed during the dry years of 1995-1997. In response, groundwater levels fell to levels similar to those experienced in 1996-1997. Analysis indicates that groundwater levels are affected by both the precipitation in the Imperial Valley area and, for wells close to the Illinois River, by river stage. Generally, water levels in wells follow antecedent precipitation and Illinois River stage by one to two months, i.e., June groundwater levels are most highly correlated with the Illinois River stage or precipitation that occurs in April or May. The analyses conducted indicate the need for continued operation of both networks due to inconsistencies associated with groundwater levels, precipitation, and the Illinois River stage. For instance, although observation well number 2 (MTOW-2) is located near the center of Mason County, well away from the Illinois River, it has an equal correlation with the Illinois River stage and area precipitation. Additional data collection and analyses are needed to determine the reasons for this and other data disparities. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-15 | | | | ISL ID: | 000000000856 Original UID: 999999994332 FIRST WORD: Operation | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | This report documents the structure and the use of a windows-based interface developed by the Illinois State Water Survey for the Office of Water Resources, Illinois Department of Natural Resources. The current version of the interface program is able to download historic, real-time, and forecasted stage and flow data from the U.S. Geological Survey, U.S. Army Corps of Engineers, and the National Weather Service websites interactively. These data are used to update existing Data Storage System (DSS) database or to create new ones; to run the UNET model for historic, design, real-time, and forecasted flood events in the Lower Illinois River; and to post-process model outputs from DSS files in tabular and graphical formats.. This interface program uses the original UNET generic geometry and boundary condition files to maintain the same level of accuracy as the UNET model, but it also allows the user to change some of the parameters, such as, the simulation time interval, time windows, and numerical Corant number, and etc., in the BC file. The real-time simulation of a flood event simulates the flood stage profiles using forecasted stage and real-time flow data downloaded from related websites. With the primary focus on simulations of levee failures, the interface program lets the users modify parameters to simulate simple levee failures through the simple spillway approach for two types of complicated embankment failures, overtopping and piping. A new simulation can be performed using the modified levee information. The change of water surface elevation induced by modifying the levees can be compared with another simulation graphically and also in table format. Stage profiles from all the simulations can be plotted together with the levee heights on both sides of the channel along the Lower Illinois River to provide a visual view of the locations of overtopping. Overtopping locations and magnitudes will be tabulated should they occur. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-16 | | | | ISL ID: | 000000000857 Original UID: 999999994333 FIRST WORD: Management | |
| | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The Cache River located in the southernmost part of Illinois flows through an area containing the Cache River Wetlands. These unique and important wetlands were designated as a Ramsar Site in 1996. Drainage activities divided the Cache River in half in the early 1900s, effectively separating the river into the Upper and Lower Cache Rivers. The Lower Cache River contains a remnant of a vast wetland system called the Lower Cache River State Natural Area (LCRSNA), commonly referred to as Buttonland Swamp. Sediment inflow from several tributary streams has an impact on the wetland. Previous research has determined that 217,000 tons of sediment were deposited in Buttonland Swamp between 1986 and 1988. The wetlands of the Lower Cache River have been targeted for preservation and restoration by state, federal, and private environmental organizations. A program to monitor the sediment deposition rate within the wetland area at regular intervals would be useful in evaluating and guiding preservation and restoration efforts. This project established a benchmark measure of the deposition rates and cross-sectional profiles at selected locations in the LCRSNA wetland. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-17 | | | | ISL ID: | 000000000858 Original UID: 999999994334 FIRST WORD: Benchmark | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Lake Decatur is the water supply reservoir for the City of Decatur. The reservoir was created in 1922 by constructing a dam to impound the flow of the Sangamon River. The dam was modified in 1956 to increase the maximum capacity of the lake to 28,000 acre-feet. The drainage area of the Sangamon River upstream of Decatur is 925 square miles and includes portions of seven counties in east-central Illinois. Lake Decatur has high concentrations of total dissolved solids and nitrates, and nitrate-N concentrations have been exceeding drinking water standards in recent years. This has created a serious situation for the drinking water supply of the City of Decatur, since nitrate-nitrogen (N) cannot be removed from finished drinking water through regular water purification processes. Nitrate-N concentrations in Lake Decatur have exceeded the Illinois Environmental Protection Agency (IEPA) drinking water standard of 10 milligrams per liter (mg/l) on occasions each year for the period between 1970 and 2000, except from 1993 to 1995. Since 1993, the Illinois State Water Survey has been monitoring the Lake Decatur watershed for trends in nitrate-N concentrations and loads and to identify any significant changes in the watershed. The purpose of the monitoring is to collect reliable hydrologic and water quality data throughout the watershed for use by city planners and resource managers to develop watershed management alternatives based on scientific data. This report presents the annual data for all seven years of monitoring (May 1993-April 2000) and monthly data for Year 7 of monitoring (May 1999-April 2000). Based on the seven years of data, it can be concluded that the unit of nitrate-N loads are relatively uniform over the entire watershed but tend to be slightly higher at the tributary streams in the upper Sangamon River watershed than at the Sangamon River stations closer to the lake. Nitrate-N loads vary with concentrations and streamflow and were the lowest in Year 7 because of the low streamflows during that year. Flow-weighted nitrate-N concentrations have been increasing during the study period at the Monticello station. The highest nitrate-N concentrations during the monitoring period were observed in years 6 and 7. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-01 | | | | ISL ID: | 000000000859 Original UID: 999999994336 FIRST WORD: Watershed | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | A dense raingage network has operated in Cook County since the fall of 1989, to provide accurate precipitation for use in simulating runoff for Lake Michigan diversion accounting. This report describes the network design, the operations and maintenance procedures, the data reduction and quality control methodology, a comparison of rainfall amounts obtained via analog chart and data logger, and an analysis of precipitation for Water Year 2001 (October 2000 - September 2001). The data analyses include 1) monthly and Water Year 2001 amounts at all sites, 2) Water Year 2001 amounts in comparison to patterns from network Water Years 1990-2000, and 3) the 12-year network precipitation average for Water Years 1990-2001. Also included are raingage site descriptions, instructions for raingage technicians, documentation of raingage maintenance, and documentation of high storm totals. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-03 | | | | ISL ID: | 000000000860 Original UID: 999999994340 FIRST WORD: Operation, | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Riparian forests have been proposed by the Technical Advisory Subcommittee of the Upper Embarras River Basin Commission in its alternatives for mitigating flood damages in the Village of Villa Grove and nearby farmlands. In order to evaluate potential reduction in flood stages in Villa Grove, methods for accounting for flow resistances induced by the riparian forests are needed in the hydraulic model for the Upper Embarras River. This project has been designed to better apply the available knowledge in practical field applications, particularly, how to evaluate the vegetal roughness in terms of Manning's andlt;EMandgt;nandlt;/EMandgt; coefficient for specified planting scenarios. Approaches presented in this report are literature review on Manning's roughness with emphasis on vegetative roughness, and evaluation and selection of methods for computing vegetative roughness due to riparian forests. The Petryk and Bosmajian (1975) method was selected for evaluating Manning's andlt;EMandgt;nandlt;/EMandgt; for mature trees because parameters could be reasonably obtained with available general field information. Using this approach, effects of riparian forest on floods were evaluated with the scenarios that the two-year floodplain has two densities of trees. The study reach was the channel between Villa Grove and Camargo. Also investigated were the options of having uniform tree density for the whole reach or half of the reach. An interface has been developed for implementing the computed andlt;EMandgt;nandlt;/EMandgt; values to a HEC-RAS hydraulic model, and capacity curves were developed to illustrate the effects on flood conveyance among these scenarios. The capacity curves thoroughly included possible boundary conditions and were presented in simple nomographs that relate discharge and downstream elevations to a specified flood elevation in Villa Grove. Therefore it was easier to evaluate the resulting effects of different alternatives. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-02 | | | | ISL ID: | 000000000861 Original UID: 999999994341 FIRST WORD: Effects | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | The Fox Chain of Lakes is a series of interconnected glacial lakes that are essentially located along the main stem of the Fox River. Originating in Wisconsin, the Fox River flows through northern Illinois before becoming a major tributary of the Illinois River. About 75 percent of the Fox River above the lowest section of the Fox Chain of Lakes lies in Wisconsin. The drainage area above the lowest point of the chain is about 1,184 square miles. The Fox Chain of Lakes has a surface area of more than 6,000 acres. Over the years, significant land-use changes have occurred on this watershed. These changes and the geographical location of the Fox River have resulted in extensive sediment deposition within these lakes. This is especially true for those lakes in the direct path of the Fox River. For example, Grass Lake and Nippersink Lake have lost most of their capacities to sediment deposition. The average depth of Grass Lake in 1975 was 2.7 feet, and the sediment is extremely soft. Within the present research activity, the original research conducted in 1974-1975 by the authors is being examined along with additional data collected by others within the last 25 years. These initial analyses indicated that both in-lake and off-lake sediment management techniques must be implemented to increase water depths within the lakes and decrease sediment loads. Among the in-lake management alternatives that should be considered are dredging and disposing of sediment outside the lake, discharging hydraulically dredged sediment into geotubes or some other type of containment facility within the lake, and creating artificial islands within the lake with dredged sediments. The watershed-based sediment management alternatives could include implementation of best management practices on the watershed, flow and sediment retention basins, side channel sediment traps, sediment management within the stream channel, and the implementation of a systemwide sediment management alternative. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-04 | | | | ISL ID: | 000000000862 Original UID: 999999994342 FIRST WORD: Sediment | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | The project objective was to assimilate the best available data to prepare digital maps of critical riparian corridors and areas at risk of flooding for the upper Embarras River, East Branch Embarras River, and Black Slough in Champaign County. Hydrologic, hydraulic, and digital data defining streams and floodplains were reconciled with digital orthophotos of the Embarras watershed. Using orthophotos as base maps, digital data sets were prepared of streams and rivers and floodplain boundaries expected for a flood having a one percent chance of occurrence in any given year. These maps were developed to provide easy-to-interpret information that identifies areas at risk during flood events. The maps were developed using ESRI ArcGIS 8.1 software and are on the attached CD-ROM in ready-to-print PDF format. The CD-ROM format is compatible with Microsoft Windows Operating System Version 95 or later. The CD-ROM contains the HEC-RAS hydraulic model used to simulate flood elevations, digital coverages used to compose the maps, digital photos of bridge crossings and landscapes of the watershed, and this report. Graphs of channel thalweg and water surface profiles showing the depth of flooding for the biennial flood event (2-year flood) and the one-percent annual chance of occurrence flood (100-year flood) provide additional information. | | | | Date Created: | 9 7 2005 | | | | Agency ID: | CR-2002-05 | | | | ISL ID: | 000000000863 Original UID: 999999994343 FIRST WORD: Embarras | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Fall application of nitrogen (N) fertilizer is a common practice in Illinois to help overcome the uncertainties of spring field work and to reduce the potential for delay in planting of spring crops. If, however, the N is applied while soil temperatures are above 50F, significant N losses can occur before the crop can take up the N. The lost N can pollute the state's water supplies, resulting in harm to the environment. The objective of this work was to provide agricultural community and public access to near real-time, 4-inch bare soil temperatures measured at 10:00 a.m. Central Standard Time (CST) each day. Hourly soil temperatures are measured at 18 automated weather stations in Illinois operated by the Illinois State Water Survey (ISWS). These stations make up the Illinois Climate Network (ICN). Measured weather variables include 4-inch sodded soil temperature, solar radiation, air temperature, relative humidity, barometric pressure, precipitation, and wind speed and direction. These data are collected, quality controlled, and placed on a Web site (http://www.sws.uiuc.edu/warm/soiltemp.asp) for public access. Daily maps of the 4-inch bare soil temperature are derived from a combination of actual 4-inch bare soil measurements at 8 ICN stations and computed bare soil temperature from 4-inch sodded soil temperature measurements from the remaining 10 sites. These maps allow users to see the general pattern of the 10:00 a.m. CST soil temperature from which they can estimate soil temperature at a given location. The other measured weather variables also are presented on the Web site in map format. Steven E. Hollinger and Robert W. Scott, Water and Atmosphere Resources Monitoring Program, Atmospheric Environment Section and Office of the Chief, Illinois State Water Survey, 2204 Griffith Drive, Champaign, Illinois 61820-7945 | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-06 | | | | ISL ID: | 000000000868 Original UID: 999999994344 FIRST WORD: Real | |
| | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | The Illinois State Water Survey (ISWS), under contract to the Imperial Valley Water Authority (IVWA), has operated a network of rain gauges in Mason and Tazewell Counties since August 1992. The ISWS also established a network of groundwater observation wells in the Mason-Tazewell area in 1994. These networks are located in the most heavily irrigated region of the state. The region's major source of water for irrigation and municipal, industrial, and domestic water supplies is groundwater pumped from thick sand-and-gravel deposits associated with the confluence of two major ancient river valleys, the Mississippi and the Mahomet-Teays. Recent extreme weather events (e.g., the drought of 1988 and the great flood of 1993) resulted in large fluctuations in groundwater levels in the Imperial Valley area. The rain gauge network and the groundwater observation well network collect long-term data to determine the rate of groundwater level decline in dry periods and during the growing season, and the rate of groundwater level recovery during recharge periods. This report presents data accumulated from the rain gauge and observation well networks since their inception through August 2001. Precipitation is recorded continuously at 20 rain gauges for each storm that traverses the Imperial Valley. Groundwater levels at the 13 observation wells are measured the first of each month. The database from these networks consists of nine years of precipitation data and seven years of groundwater observations. At the beginning of groundwater observations in late 1994, the water levels were at their highest in the seven years of observation. These high groundwater levels were the result of the very wet 1992-1995 period when annual precipitation was above the 30-year normals at both Havana and Mason City. From September 1995-August 1997, precipitation in the region was well below the 30-year normal followed by the 1997-1998 and 1998-1999 observation years with rainfall totals slightly above and slightly below normal, respectively. Groundwater levels in the observation wells reflected the multi-year rainfall patterns, showing a general downward trend during dry years, a recovery in wet 1997-1998, and a leveling off in near-normal 1998-1999, followed by declines in dry 1999-2000. Despite a dry July, near-normal precipitation in 2001 brought a return to more typical seasonal hydrographs. This report includes new regression analyses of data collected through August 2001, similar to regression analyses first conducted on data collected through August 1998. The analyses indicate that groundwater levels are affected by precipitation in the Imperial Valley area and, for wells close to the Illinois River, by river stage. Generally, water levels in wells follow antecedent precipitation and Illinois River stage by one to two months; e.g., a high correlation between June groundwater levels and the Illinois River stage or precipitation that occurs in April or May. However, additional data collected since 1998 did not improve the results of the regression analyses. In fact, coefficients of determination for many regressions worsened. This suggests that regressions of observed groundwater levels versus river stage and precipitation are not adequately describing all the variables affecting groundwater levels. Using the data collected to verify, test, and improve the existing Imperial Valley groundwater flow model is highly recommended. Continued data collection also is recommended to create long-term data sets of precipitation and groundwater levels for use in modeling analyses. Collection of additional groundwater level and irrigation pumpage data also is highly recommended. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-07 | | | | ISL ID: | 000000000869 Original UID: 999999994345 FIRST WORD: Operation | |
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