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801:		Title:	Amendatory Order
		Volume/Number:
		Issuing Agency:
		Description:	Joint Petition for Approval of a Negotiated Interconnection Agreement pursuant to 47 U.S.C. 252.
		Date Created:	09 26 2006
		Agency ID:	06-0308
		ISL ID:	000000000820 Original UID: 824 FIRST WORD: Amendatory

802:		Title:	Amendatory Order
		Volume/Number:
		Issuing Agency:
		Description:	Joint Petition for Approval of a Negotiated Interconnection Agreement pursuant to 47 U.S.C. 252.
		Date Created:	09 26 2006
		Agency ID:	06-0309
		ISL ID:	000000000821 Original UID: 825 FIRST WORD: Amendatory

803:		Title:	Order
		Volume/Number:
		Issuing Agency:
		Description:	Citation for failure to file Annual Report.
		Date Created:	09 26 2006
		Agency ID:	06-0313
		ISL ID:	000000000822 Original UID: 826 FIRST WORD: Order

804:		Title:	Order
		Volume/Number:
		Issuing Agency:
		Description:	Citation for failure to file Annual Report.
		Date Created:	09 26 2006
		Agency ID:	06-0325
		ISL ID:	000000000823 Original UID: 829 FIRST WORD: Order

805:		Title:	Order
		Volume/Number:
		Issuing Agency:
		Description:	Joint Petition for Approval of Negotiated Interconnection Agreement dated July 6,2006, pursuant to 47 U.S.C. 252.
		Date Created:	09 26 2006
		Agency ID:	06-0500
		ISL ID:	000000000824 Original UID: 844 FIRST WORD: Order

806:		Title:	Amendatory Order
		Volume/Number:
		Issuing Agency:
		Description:	Consideration of the federal standard On interconnection in Section 1254 of The Energy Policy Act of 2005.
		Date Created:	09 26 2006
		Agency ID:	06-0525
		ISL ID:	000000000825 Original UID: 845 FIRST WORD: Amendatory

807:		Title:	Pilot study: agricultural chemicals in rural, private wells in Illinois
		Volume/Number:	1992
		Issuing Agency:
		Description:	In the Illinois Groundwater Protection Act of 1987 (PA 85-863), the state legislature mandated that the Illinois Department of Energy and Natural Resources (DENR) conduct an "ongoing program of basic and applied research relating to groundwater," including an evaluation of pesticide impacts upon groundwater. "Such evaluation shall include the general location and extent of any contamination of groundwaters resulting from pesticide use. . . . Priority shall begven to those areas of the State where pesticides are utilized most intensively." In response to this mandate, the Illinois State Water Survey (ISWS) and the Illinois State Geological Survey (ISGS), divisions of DENR, developed a plan to assess the occurrence of agricultural chemicals in rural, private wells on a statewide basis (McKenna et al. 1989). In response to the concerns regarding the proposed statewide survey, a separate pilot study was designed, based on the recommended statewide survey, to produce tangible, documented results of well-water sampling and to demonstrate the validity of the survey design.The legislative mandate addressed the pesticide impacts on groundwater. The proposed statewide plan and the pilot study will focus on groundwater drawn from rural, private wells. This approach will maximize data acquisition on the potential for exposure of the rural residents of Illinois to agricultural chemicals (pesticides and nitrogen fertilizers) through drinking water; it will also minimize sample collection costs. Inferences drawn from this project are valid for groundwater drawn from rural, private wells and not from other sources.
		Date Created:	9 24 2004
		Agency ID:	COOP-14
		ISL ID:	000000000826 Original UID: 999999993861 FIRST WORD: Pilot

808:		Title:	Contribution to the characterization of Illinois reference/background conditions for setting nitrogen criteria for surface waters in Illinois : final report to Illinois Council on Food and Agricultural Research (C-FAR)
		Volume/Number:	2000
		Issuing Agency:
		Description:	The United States Environmental Protection Agency (USEPA) National Regional Nutrient Criteria Development Program is developing regional-specific criteria for total nitrogen concentrations in surface waters. These criteria will provide the foundation for states to set total nitrogen standards to remedy impairments caused by nutrient overenrichment and to protect designated uses. Reference conditions representing minimally impacted surface waters will be developed for each ecoregion. All nutrient criteria must be based on sound scientific rationale. The first element of a nutrient criterion identified by USEPA is "... historical data and other information to provide an overall perspective on the status of the resource." The second element includes " ... a collective reference condition describing the current status." A further element requires "... attention to downstream consequences." The USEPA recognizes that nutrient concentrations in surface waters are primarily affected by the rate of weathering and erosion from watershed soils. Human activity can affect on the natural load of nutrient inputs to surface waters through, for example, vegetation disturbance of the vegetation, and addition of nutrient-containing material, such as fertilizer. At the heart of the overenrichment problem are the rates of production and decomposition of organic materials, of which nitrogen is a component. This report provides a contribution to the setting of reference/background conditions for Illinois through the evaluation of the current status of water resources against historical conditions, and some attention to downstream consequences. A particular focus of downstream consequences is hypoxia in the Gulf of Mexico, allegedly caused by the flux of excess nitrogen from the Upper Mississippi, Ohio, and Missouri River Basins. The concept of biogeochemical cycling provides an appropriate and necessary framework for understanding landscape influences on water quality throughout the Illinois River Basin. Changes in the Illinois River Valley and its system of tributary streams and lakes are well recognized, but this is the first attempt to assess in some detail how such changes have affected the aquatic carbon, oxygen, and nitrogen cycles; especially the impact of such watershed changes on the nature and quantity of aquatic nitrogen, as well as on the nitrogen cycle within the terrestrial reservoir. This is seen in the accompanying time line of the estimated nitrogen richness of the Illinois landscape. Scientists studying soils and crops from the mid-19th through mid-20th centuries documented that human activities have greatly altered the natural nitrogen cycle. Cultivation of virgin land typically depleted nitrogen and carbon stored in these reservoirs by about 50 percent in the first 60-70 years of cultivation. Some of this nitrogen was transferred to surface waters and ground waters. The depletion of nitrogen from soils in the Mississippi River Basin was so great that crop yields declined throughout the 19th and early 20th centuries. By mid-20th century, the extensive use of nitrogen fertilizer, improved plant varieties, and agronomic practices increased crop yields. Nitrogen fertilizer also began to replenish some of the large amounts of nitrogen previously removed from the soil. In the 1970s, profound changes occurred in the perception of the natural nitrogen cycle and human modification of that cycle. The nitrogen cycle, and human impacts on it came to be defined in terms of atmospheric nitrogen fixation and the return of nitrogen gases by nitrification/denitrification. The 99 percent of the nitrogen cycle which was otherwise cycled within and between the large soil, sediment, and plant reservoirs were no longer acknowledged. From this new definition of the nitrogen cycle, it was concluded that human activities, especially fossil-fuel combustion and fertilizer use, had doubled the nitrogen cycle and many lands, including much of Illinois, had become nitrogen saturated. Increasing concentrations of nitrate-nitrogen in surface waters were given as evidence of nitrogen saturation and leakage. This new limited edition of the nitrogen cycle became cast in concrete and is referred to in this report as "the new, standing nitrogen-cycle paradigm." This report uses the earlier, scientifically more complete and defensible definition of the nitrogen cycle, which includes recognition of the magnitude and importance of soil-plant reservoirs and exchanges. It uses extensive scientific documentation of major changes in ecosystems and soil nitrogen that have occurred over centuries, to place into perspective the present status of nitrogen resources -- as required by USEPA. This report examines the impact on nitrogen concentrations in surface waters in Illinois during occupation of the land by Native Americans, bison, and many other animals and birds. Theoretical impacts are complemented by written accounts of early settlers and scientific observations made under similar conditions. It is concluded that the landscape and surface waters were more nitrogen saturated at this time than today. These pre-European-settlement conditions were selected as the reference/background conditions. Just prior to and during the period of early European settlement, the populations of Native Americans and bison were eliminated and the landscape became less nitrogen saturated. Nevertheless, even in the 1820s, the Illinois River was hypertrophic, i.e. nutrient overenriched. As late as the 1850s, the amount of eroded soil transported by the Mississippi River was more than twice that transported in recent decades. Since soil erosion is reported to be the major sort of N delivery from agricultural lands, the N load in the Mississippi River was declining. The average annual concentration of total nitrogen in the Lower Illinois River in 1894-1899 was 3.68 mg N/l, and additional large amounts of nitrogen not measured were stored in plankton and luxuriant aquatic vegetation and transported downstream in copious amounts of organic debris. Allowing for the unmeasured flux of nitrogen as plankton and for low flow, the adjusted average annual concentration of total nitrogen in the Lower Illinois River in 1894-1899 is estimated to have been about 5.5 mg N/l. This report also examines the impact of European settlement and agriculture on the nitrogen cycle and water quality. Scientific data show that the average concentration of total nitrogen in the Lower Illinois River increased to about 10 mg N/l by mid-20th century and subsequently decreased to 4.8 mg N/l in the 1990s. The annual concentration of nitrate in the Lower Illinois River peaked at about 6.2 mg N/l in 1967-1971 and subsequently decreased to about 3.8 mg N/l in 1993-1998. These improvements in water quality are associated with an increasing amount of dissolved oxygen in the river. The reductions in the concentrations of all forms of nitrogen are attributable to both point- and nonpoint-source pollution control. The main conclusions of this report are that, in establishing scientifically sound reference/background conditions, it is necessary to quantify in a common unit all forms of nitrogen (in solution, as solids, and as gases; and organic and inorganic forms) and all sources, reservoirs, transformations, and fluxes of nitrogen in a common unit; and to understand interactions between nitrogen and other biogeochemical cycles of, for example, water, oxygen, carbon, and phosphorous. Criteria for setting nitrogen standards must recognize the great complexity of the nitrogen cycle and its interdependence with other variables, cycles, and anthropogenic influences.
		Date Created:	9 24 2004
		Agency ID:	CR-2000-08
		ISL ID:	000000000827 Original UID: 999999994193 FIRST WORD: Contribution

809:		Title:	Phase I: diagnostic-feasibility study of Homer Lake, Champaign, Illinois.
		Volume/Number:	2000
		Issuing Agency:
		Description:	The Champaign County Forest Preserve District (CCFPD) applied for and received a grant to conduct a diagnostic-feasibility study on Homer Lake commencing in April 1997. Homer Lake is an 83-acre public lake within the Salt Fork River Forest Preserve in Champaign County, Illinois. The lake is located in the Second Principle Meridian, Township 19N, Range 14W, Section 31; it is 3 miles northwest of the town of Homer. Homer Lake has a maximum depth of 19 feet, a mean depth of 7.4 feet, a shoreline length of .3 miles, and an average retention time of 0.097 years. The Homer Lake watershed, including the lake surface area, is 9,280 acres. The two inflow tributaries are Conkey Branch and the west branch (unnamed). The diagnostic study was designed to delineate the existing lake conditions, to examine the cases of degradation, if any, and to identify and quantity the sources of plant nutrients and any other pollutants flowing into the lake. On the basis of the findings of the diagnostic study, water quality goals were established for the lake. Alternative management techniques were then evaluated in relation to the established goals.
		Date Created:	9 24 2004
		Agency ID:	CR-2000-13
		ISL ID:	000000000828 Original UID: 999999994305 FIRST WORD: Phase

810:		Title:	Dewatering well assessment for the highway drainage system at five sites in the east St. Louis area, Illinois (FY95-Phase12)
		Volume/Number:	2000
		Issuing Agency:
		Description:	In the East St. Louis vicinity, the Illinois Department of Transportation, Division of Highways (IDOT) owns 55 high-capacity wells that are used to maintain the elevation of the ground-water table below the highway surface in areas where the highway is depressed below the original land surface. The dewatering systems are located at five sites in the alluvial valley of the Mississippi River in an area known as the American Bottoms. The alluvial deposits at the dewatering sites are about 90 to 115 feet thick and consist of fine sand, silt, and clay in the upper 10 to 30 feet, underlain by medium to coarse sand about 70 to 100 feet thick. The condition and efficiency of a number of the dewatering wells became suspect in 1982 on the basis of data collected and reviewed by IDOT staff. Since 1983, IDOT and the Illinois State Water Survey (ISWS) have conducted a cooperative investigation to more adequately assess the operation and condition of the wells, to attempt to understand the probable causes of well deterioration, and to evaluate rehabilitation procedures used on the wells. Work conducted during FY 95 (Phase 12) included monitoring the rehabilitation of four wells, step-testing the rehabilitated wells and checking the discharge from two wells for sand pumpage, checking the quality of the water discharged during the step tests, and monitoring the ground-water levels at the dewatering system sites. Posttreatment step tests were used to help document the rehabilitation of four dewatering wells, Interstate-70 (I-70) Wells 3A, 5, 11A, and 15, during FY 95 (Phase 12). Chemical treatments used to restore the capacity of these four wells were moderately successful. The improvement in specific capacity per well averaged about 103 percent based on data from pre- and posttreatment step tests. The specific capacity of I-70 Well 15 was restored to about 109 percent of the average observed specific capacity of wells in good condition at the I-70 site and the other three wells were restored to about 72 to 87 percent of the average observed specific capacity for wells in good condition. The sand pumpage investigation conducted during the posttreatment step tests on I-70 Wells 3A and 11A showed little or insignificant amounts of sand in the portable settling tank after the step tests. The tank was required to divert the discharged water into the stormwater drainage system during the other two step tests, precluding a check for sand pumpage.
		Date Created:	9 24 2004
		Agency ID:	CR-2000-10
		ISL ID:	000000000829 Original UID: 999999994306 FIRST WORD: Dewatering

811:		Title:	Operation of rain gauge and ground-water monitoring networks for the Imperial Valley Water Authority, year seven : September 1998-August 1999
		Volume/Number:	2000
		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 ground-water 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 ground water 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 ground-water levels in the Imperial Valley area. The purpose of the rain gauge network and the ground-water observation well network is to collect long-term data to determine the rate of ground-water 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 and November 1999, respectively. Precipitation is recorded for each storm that traverses the Imperial Valley, and ground-water levels at the 13 observation wells are measured the first of each month. The database from these networks consists of seven years of precipitation data and five years of ground-water observations. At the beginning of the ground-water observations in late 1994, the water levels were at their highest in the five years of observation. These high ground-water 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 below the 30-year normal. The 1997-1998 observation year had rainfall above the 30-year normal. Ground-water levels in the observation wells mirrored these rainfall patterns, showing a general downward trend during the dry years and a recovery in the wet 1997-1998 year. Seasonal increases in the ground-water levels were observed at most wells during the late spring and early summer, followed by decreases in August-November ground-water levels. Analysis indicates that the ground-water levels are affected by both the precipitation in the Imperial Valley area and the Illinois River stages. The observation wells closest to the Illinois River show an increase in water levels whenever the river stage is high. Generally, the water levels in the wells correlate best with precipitation and Illinois River stages one to two months before the water levels are measured, i.e., the June ground-water levels are most highly correlated with the Illinois River stage or precipitation that occurs in either April or May. The analyses conducted indicate the need for continued operation of both networks due to inconsistencies associated with ground-water levels, precipitation, and the Illinois River stage. For instance, the Mason-Tazwell observation well number 2 (MTOW-2) is located near the center of Mason County well away from the Illinois River, but it has an equal correlation with the Illinois River stage and the precipitation in the area. Additional analysis needs to be undertaken to explain this unusual finding.
		Date Created:	9 24 2004
		Agency ID:	CR-2000-12
		ISL ID:	000000000830 Original UID: 999999994307 FIRST WORD: Operation

812:		Title:	Watershed monitoring for the Lake Decatur watershed, 1998-1999
		Volume/Number:	2000
		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 with an original water volume of 20,000 acre-feet and an area of 4.4 square miles. The dam was later modified in 1956 to increase the maximum capacity of the lake to 28,000 acre-feet. Water withdrawal from the lake has been increasing over the years, averaging 37 million gallons per day (mgd) in 1994. The drainage area of the Sangamon River upstream of Decatur is 925 square miles. The watershed includes portions of seven counties in east-central Illinois. The predominant land use in the watershed is row crop agriculture comprising nearly 90 percent of the land area. The major urban areas within the watershed are Decatur, Monticello, and Gibson City. Lake Decatur has high concentrations of total dissolved solids and nitrates, and nitrate 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. The Illinois Environmental Protection Agency (IEPA) has issued nine nitrate warnings to the city from 1979 to 1996 for noncompliance with Nitrate-N concentrations in Lake Decatur have exceeded the Illinois Environmental Protection Agency (IEPA) drinking water standards for nitrate when concentrations exceeded of 10 milligrams per liter (mg/l) for the period between 1979 and 1998, except from 1993 to 1995. On June 10, 1992, a Letter of Commitment (LOC) was signed between the IEPA and the City of Decatur. The LOC requires the city to take several steps to reduce nitrate levels in Lake Decatur to acceptable concentrations within nine years of signing the LOC. Nitrate-N cannot be removed from finished drinking water through regular water purification processes. One of the steps required the city to conduct an initial two-year monitoring study of the Lake Decatur watershed to better understand nitrate yields in the watershed. In 1993, the Illinois State Water Survey received a grant from the City of Decatur, conducted a two-year monitoring study, and developed land use management strategies that could assist the city comply with the IEPA drinking water standards (Demissie et al., 1996). This technical report presents the annual data for all six years of monitoring (May 1993-April 1999) and monthly data for the sixth year of monitoring (May 1998-April 1999).
		Date Created:	9 24 2004
		Agency ID:	CR-2000-06
		ISL ID:	000000000831 Original UID: 999999994310 FIRST WORD: Watershed

813:		Title:	Bank erosion survey of the Illinois River : volume 2 : appendices
		Volume/Number:	2000
		Issuing Agency:
		Description:	This report summarizes the research and surveying that were conducted in 1995 to determine the amount and severity of bank erosion that existed on the entire length of the Illinois River. The study reach extended from Grafton, River Mile (RM) 0 to Joliet, RM 286. A multi-disciplinary team of scientists traveled the entire length of the river, mapped bank conditions and erosion sites, and selected 29 reaches for detailed data collection and two sites as observation sites. Bank erosion types were developed by studying and analyzing the erosion features. The team also used fluvial and bank failure processes to guide detailed data collection at the 29 sites. Color-coded bank feature maps were developed for the entire 286 miles of the river.
		Date Created:	8 16 2005
		Agency ID:	CR-2000-11v.2
		ISL ID:	000000000832 Original UID: 999999994312 FIRST WORD: Bank

814:		Title:	Continued operation of a raingage network for collection, reduction, and analysis of precipitation data for Lake Michigan diversion accounting: Water Year 2000
		Volume/Number:	2001
		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 purposes of Lake Michigan diversion accounting. This report describes the network design, the operations and maintenance procedures, the data reduction methodology, and an analysis of precipitation for Water Year 2000 (October 1999 through September 2000). The data analyses include 1) monthly and Water Year 2000 amounts at all sites, 2) Water Year 2000 amounts in comparison to patterns from network Water Years 1990-1999, and 3) the 11-year network precipitation average for Water Years 1990-2000. 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-2001-02
		ISL ID:	000000000833 Original UID: 999999994313 FIRST WORD: Continued

815:		Title:	Water quality trends of the Illinois Waterway system upstream of Peoria including the Chicago metropolitan area.
		Volume/Number:	2001
		Issuing Agency:
		Description:	The long-term temporal trends of water quality in the Illinois Waterway system upstream of Peoria are described in this report. The time period investigated was from 1965 to 1995. The seasonal Kendall trend test was used to detect statistically significant trends. A related test, the seasonal Kendall slope estimator, was used to calculate the magnitude of the trend. Box plots were also used to visualize differences in data over time. The water quality analytes considered in this report include dissolved oxygen, ammonia-nitrogen, nitrate and nitrite-nitrogen, total Kejeldahl nitrogen, total phosphorous, sulfate, turbidity, total suspended solids, fecal coliform, cyanide, and phenol. Water quality was generally found improved at all stations. Substantial improvements were found at most stations for dissolved oxygen, the nitrogen species, phenol, and cyanide concentrations. Fecal coliform densities generally decreased at most locations. Little or variable change was found for turbidity, total suspended solids, and total phosphorus concentrations. Increasing trends were detected for sulfate concentrations.
		Date Created:	9 24 2004
		Agency ID:	CR-2001-03
		ISL ID:	000000000834 Original UID: 999999994314 FIRST WORD: Water

816:		Title:	Sedimentation survey of Highland Silver Lake, Madison County, Illinois
		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. Silver Lake is Located in Madison County, one mile northwest of Highland, Illinois. The location of the dame is 38 degrees 46' 00" north latitude and 89 degrees 42' 05" west longitude in Section 30, T.4N., R.5W., Madison County, Illinois. The dam impounds the East Fork of Silver Creek, a tributary of Silver Creek in the Kaskaskia River basin. The watershed is a portion of Hydrologic Unit 07140204 as defined by the U.S. Geological Survey. Construction of the lake was completed in 1962. The Silver Lake watershed consists of the 47.1-square-mile area drained by the East Fork of Silver Creek above the dam site. Land use in the watershed of the lake is mainly agricultural. Average annual precipitation in the area is 38.98 inches as measured at Greenville (1961-1990), and the average runoff (1912-1998) is approximately 10.0 inches (Shoal Creek near Breese). Average annual lake evaporation rates are 35.2 inches per year at St. Louis, Missouri. The Illinois State Water Survey conducted sedimentation surveys of Silver Lake in 1981 and 1984. In 1981, cross sections were laid out at 14 lines across the lake and surveyed. Sedimentation surveys of Silver Lake in 1984 and 1999 repeated as closely as possible the series of survey lines established during the 1981 survey. Sedimentation has reduced the capacity of Silver Lake from 7,322 acre-feet or ac-ft (2,386 million gallons) in 1962 to 5,832 ac-ft (1,900 million gallons) in 1999. Sediment accumulation rates in the lake have averaged 40.3 ac-ft per year from 1962-1999. Annual sedimentation rates for three separate periods, 1962-1981, 1981-1984, and 1984-1999, were 51.2, 63.0, and 21.9 ac-ft, respectively. Density analyses of the sediment samples indicate that sediment in the northern (upstream) portions of the lake has greater unit weight than 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 shallow 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. The sedimentation rate for Highland Silver Lake is similar to the rates for other Illinois lakes of similar size and character. The sedimentation for Silver Lake is in the low to average ranged compared to other Illinois lakes.
		Date Created:	9 24 2004
		Agency ID:	CR-2001-05
		ISL ID:	000000000835 Original UID: 999999994316 FIRST WORD: Sedimentation

817:		Title:	Hydrology of the Big Creek Watershed and its influence on the Lower Cache River
		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

818:		Title:	Bank erosion survey of the main stem of the Kankakee River in Illinois and Indiana.
		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

819:		Title:	Sedimentation survey of Lake Decatur's Basin 6, Macon County, Illinois.
		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

820:		Title:	The impact of emergency pumpage at the Decatur wellfields on the Mahomet aquifer: model review and recommendations
		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

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