FLOOD07698

• County: Statewide
• Community: Rock Rapids, Iowa
• Basin: Statewide
• Title: Problem Identification Report Rock River at Rock Rapids Reconnaissance Study Section 205
• Date: 4/1/1995
• Prepared For: US Army Corps of Engineers
• Prepared By: Greenhorne & O'Mara, Inc.
• Floodplain - Doc Type: Project

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Vet lands are located within the study area at various locations

along the Rock River, Tom Creek, and Moon Creek, based upon

photointerpretation and evaluation of National Vetland Inventory (NVll

maps. The Cowardian classifications of wetlands in the project area

include palustrine emergent (PEKl. palustrine unconsolidated bottom (PUBl.

riverine lower perennial (R2l, and riverine intermittent (R4l.

According to the Big Sioux Vildlife Management Unit of the Iowa

Department of Natural Resources (DNRl, limited marshy habitat is present

at the mouth of Koon Creek at Island Park. The marshy area and

surrounding flood plain timber provide excellent habitat for wood duck,

deer, and various nongame species. A rare saw-whet owl was reportedly

seen in this area several years ago.

Two plant species which are listed as threatened by the U.S, Fish and

Vildlife Service (USFVS) may be present in the study area. These are the

western prairie fringed orchid (Platanthera Draeclaral and the prairie

bush clover (LesDedeza leDtostachval. Both are considered to potentially

occur statewide. The western prairie fringed orchid occupies wet

grassland habitats and the prairie bush clover occupies dry to mesic

prairies with gravelly soils. According to the soils survey, prairie

remnants are not common in this part of Lyon County (U.S. Department of

Agriculture (USDAl, 1978l.

SOCIAL AND ECONOKIC SETTING
PODulation. The 1990 U.S. Census of Population and Housing reported
a total population of 2,601 persons for Rock Rapids, Iowa, which compares
to 11,952 within Lyon County and approximately 2,829,000 for the State
of Iowa. The Rock Rapids population represents about 22 percent of the
county population and less than 0.1 percent of the State population.
The population of Rock Rapids has remained relatively steady over the
past 20 years according to the office of the City Administrator. The
Rock Rapids Comprehensive Plan (Selander and Associates, 1969l states
that Rock Rapids could anticipate moderate growth in the future if
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