USACE CWMS - Kaskaskia Watershed

The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin:
- GeoHMS (Geospatial Hydrologic Modeling Extension)
- ResSIM (Reservoir System Simulation)
- RAS (River Analysis System)
- FIA (Flood Impact Analysis)

The Kaskaskia River basin is the second largest basin in the state of Illinois, covering approximately 5,790 square miles. The headwaters are in the center of Champaign County, and the basin flows in a southwesterly direction. The basin drains to the Mississippi River, and the outlet is just upstream of the city of Chester, Illinois. The basin is roughly 175 miles long and has an average width of 33 miles. The Kaskaskia River has a very sinuous channel with low banks and a small slope. During times of heavy rains, the valleys in the basin can be subjected to serious flooding. The primary land use in the basin is agriculture. There are some urbanized areas in the watershed, including the St. Louis Metro East, Champaign, Vandalia, and other small towns spread throughout the basin.
There are two reservoirs constructed and operated by the US Army Corps of Engineers in the watershed: Lake Shelbyville and Carlyle Lake. Both dams are located on the main stem of the Kaskaskia River and are operated in tandem by the St. Louis District. The purpose of the reservoirs are to provide flood damage reduction, to create recreational opportunities, to augment water supply, to enhance water quality, to augment flows for navigation on the lower Kaskaskia River, and to provide fish and wildlife conservation. There is a Lock and Dam at the lower end of the Kaskaskia River, located approximately one mile upstream of the confluence with the Mississippi River. This structure provides sufficient depth for the navigation channel, which runs from the mouth to Fayetteville, Illinois, approximately 36 miles upstream. The Kaskaskia River was straightened and widened to provide for consistent navigation through this stretch. Upstream of Fayetteville the Kaskaskia River returns to its natural state.

Corps 水资源管理系统（CWMS）集成了四个相互关联的模型，旨在辅助流域的水资源管理：
- GeoHMS（地理水文建模扩展）
- ResSIM（水库系统模拟）
- RAS（河流分析系统）
- FIA（洪水影响分析）

卡斯卡斯基亚河流域为伊利诺伊州第二大流域，总面积约5,790平方英里。源头位于查帕宁县中心，流域流向为西南方向。流域最终汇入密西西比河，出口位于伊利诺伊州切斯特市上游。流域全长约175英里，平均宽度约为33英里。卡斯卡斯基亚河拥有一个非常蜿蜒的河道，河岸低矮，坡度平缓。在暴雨期间，流域内的山谷可能会遭受严重洪涝。流域内的主要土地利用类型为农业。在水系中还有一些城市化区域，包括圣路易斯米特罗伊斯特、查帕宁、万达利亚以及其他散布于流域中的小镇。

美国陆军工程兵团在流域内修建并运营了两座水库：谢尔比维尔湖和卡利尔湖。两座大坝均位于卡斯卡斯基亚河的主干道上，并由圣路易斯区协同运营。水库的目的是为了提供洪水灾害减免、创造休闲机会、增加水资源供应、改善水质、增强下游卡斯卡斯基亚河的航运流量，以及提供鱼类和野生动物保护。在卡斯卡斯基亚河下游末端，有一座船闸和堤坝，位于密西西比河汇合点上游大约一英里处。该结构为航道提供了足够的深度，航道从河口延伸至伊利诺伊州费耶特维尔上游约36英里。卡斯卡斯基亚河在此段被拓宽并直化，以确保航道的持续畅通。在费耶特维尔上游，卡斯卡斯基亚河恢复其自然状态。