Sediment Deposition in Cochiti Reservoir: 3D Comparison to Pre-Dam Conditions

Scott Perkins, GISP
Wilson & Company
Albuquerque, NM

Nathan Kempf
Wilson & Company
Albuquerque, NM

Since completion of Cochiti Dam in 1975, sediment has been steadily accumulating within Cochiti Reservoir and upstream within the Rio Grande channel. Aerial photography from 1963 & 1972 has been georeferenced with ground coordinates to prepare a digital terrain model (DTM) of pre-dam conditions.

Aerial photography and bathymetry of Cochiti Reservoir & the Rio Grande in 1999 & 2004 has been georeferenced to the same ground coordinates to provide a recent DTM. Comparison between these data sets clearly shows both quantity and spatial distribution of sediment deposition over time. These temporal DTM’s yield comparative analysis of reservoir storage capacity; sediment volume and distribution trends; cross section profiles; forecasting of sediment inflow and life expectancy of Cochiti Reservoir; and river baseline elevation change. To provide visualization of this phenomenon, examples from different dates of photography, DTM, and bathymetry will be displayed in 3D with special projection equipment.

A brief description of methodology, data compilation and analysis will be given.
Floodplain managers and water resource managers will find this presentation of interest.

This project was completed by the Survey, Geospatial and Remote Sensing Division of Wilson & Company for the Albuquerque District of the US Army Corps of Engineers.

Note*** 3D viewing glasses will be provided.