USACE CWMS - Iowa River 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 Iowa River basin is the second largest basin in the state of Iowa, covering approximately 12,640 square miles. The headwaters originate at in Hancock County, IA. Spanning almost the entire state from North to South, the basin generally flows in a southeasterly direction and drains to the Mississippi River, with the outlet located just upstream of the city of New Boston, Illinois. The basin is roughly 360 miles long and has an average width of 55 miles. The Iowa River has a mildly 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 as was seen in the 2008 flood of record. The primary land use in the basin is agriculture. The largest urbanized areas in the watershed (population over 10,000), include Iowa City, Coralville, Cedar Rapids, Waterloo, Cedar Falls, Mason City, and Marshalltown. There are also several other small towns located along the banks of the Iowa River and spread throughout the basin.

There is one reservoir constructed and operated by the US Army Corps of Engineers in the watershed: Coralville Lake. The dam is located on the main stem of the Iowa River and is operated by the Rock Island District. The primary purpose of the reservoir is to provide flood damage reduction and low flow augmentation for the lower Iowa River. The secondary benefits of the reservoir include enhancing recreational opportunities, providing fish and wildlife conservation, and improving land use management. There are no Locks located along the Iowa River as there is not sufficient width or depth for a navigation channel.

美国陆军工程兵团水资源管理系统（Corps Water Management System, CWMS）包含四个相互关联的模型，用于辅助流域水资源管理：
- GeoHMS（地理空间水文模拟扩展工具, Geospatial Hydrologic Modeling Extension）
- ResSIM（水库系统模拟器, Reservoir System Simulation）
- RAS（河道分析系统, River Analysis System）
- FIA（洪水影响分析工具, Flood Impact Analysis）

爱荷华河流域是爱荷华州境内第二大流域，总面积约12640平方英里。其源头位于爱荷华州汉考克县。该流域几乎纵贯爱荷华州南北全境，整体流向大致呈东南方向，最终注入密西西比河，河口位于伊利诺伊州新波士顿市上游不远处。流域全长约360英里，平均宽度为55英里。爱荷华河河道蜿蜒平缓，堤岸低矮且坡度较小。强降雨时段，流域内河谷极易发生严重洪涝，正如2008年有记录以来的特大洪水所印证的那样。该流域的主导土地利用类型为农业。流域内人口超1万的大型城区包括艾奥瓦城、科勒尔维尔、锡达拉皮兹、滑铁卢、锡达福尔斯、梅森城以及马歇尔敦。此外，沿爱荷华河河岸及流域内各地还分布有若干小型城镇。

该流域内由美国陆军工程兵团修建并运营的水库仅有科勒尔维尔湖一座。大坝坐落于爱荷华河干流之上，由岩岛分区负责运营管理。该水库的核心功能为降低爱荷华河下游的洪水灾害损失，并为下游河道补充枯水流量。其附带效益包括优化休闲娱乐体验、保护鱼类与野生生物资源，以及提升土地利用管理水平。由于通航航道所需的宽度与深度均不达标，爱荷华河沿岸未设置船闸。