Elephant Butte Reservoir Project
Elephant Butte Reservoir is part of the Middle Rio Grande Project in southwest New Mexico. Originally authorized under the Federal Reclamation Act of 1902, the project serves the multiple purposes of irrigation, flood control, power generation, recreation, and water storage. The reservoir was created by construction of a concrete gravity dam, 1,644 feet long and 302 feet tall, completed in 1916.
Recently the Bureau of Reclamation needed to obtain detailed elevation data to support hydraulic modeling, planning, and design of river maintenance activities in the Elephant Butte Reservoir reach. Their area of interest covered the entire valley between the East and West mesas, about 43,500 acres in all. The valley floor is flat to rolling and is bordered by low-lying levees and bluffs. Incised by the river channel, the Elephant Butte Reservoir reach contains dense vegetation in some areas including salt cedar or tamarisk. This particular vegetation not only makes it problematic to obtain accurate ground measurements but it is an invasive species whose extent the Bureau wanted to measure.
AeroMetric mobilized a crew and aircraft equipped with a LiDAR sensor to a base in nearby Socorro. The detailed acquisition plan required AeroMetric’s pilot to coordinate acquisition flights with military flight operations control for “hot” areas adjacent to the project. LiDAR data was acquired from an average altitude of 4000 feet above terrain using flight lines designed to provide 60% overlap to ensure complete coverage and provide a high level of redundancy. Ground stations were established and occupied by a local surveying company and AeroMetric BOR contract team member who also surveyed ground profiles for use in processing and QC of the LiDAR data. During the acquisition flights GPS data was collected on two ground stations at a one second epoch rate which was used in the kinematic solution for the sensor positioning. Following post processing, the LiDAR point cloud data was classified into first return, default (vegetation, structures, etc.), and bare earth. After the final QC check AeroMetric delivered a Triangulated Irregular Network Model and bare-earth Digital Elevation Model suitable for generation of cross sections or 2-foot contours along with the associated metadata and project report.
The Bureau utilized the deliverables prepared by AeroMetric to successfully complete modeling, planning, and design activities as an integral part of long term project maintenance and fulfillment of their reclamation mission. For more information about the Middle Rio Grande project, please visit the project site.
