Featured Projects

The Problem:

The number of proposed projects along Martin Slough and post-Flood Insurance Rate Map (FIRM) changes to the Martin Slough floodplain was such that Douglas County engineers decided that updated maps of the regulatory floodplain were necessary. The original mapping was done for the Federal Emergency Management Agency (FEMA) by a contractor, likely the Sacramento District of the U.S. Army Corps of Engineers (USACE). Additionally, conditions near the downstream end were such that a significant portion of the base flood discharge is diverted by U.S. 395 north along the east side of the highway. This differs considerably from the assumptions used in the original modeling.

​

The Solution:

An existing conditions model and Letter of Map Revision (LOMR) were prepared for the study reach. The project was revised to include an analysis of the reach downstream from U.S. 395 to East Fork Carson River and the development of a floodway for the remaining parts of the study reach of Martin Slough. LiDAR topography, supplemented with field surveys, was used to develop a suite of models of Martin Slough. This suite included an existing conditions model, as well as a duplicate effective model, using more than 80 cross sections for the analysis.

​

The Results:

Completion of the project resulted in the presentation of a report and supporting materials for the application. FEMA reviewed the materials and a LOMR was issued for the study reach of Martin Slough.