The US Army Corp of Engineers has released a preliminary study regarding the "Forgotten River", the stretch of Rio Grande between Fort Quitman and Presidio.  This project was made possible by


Table of Contents

Chapter 1 – Overview  
 
Chapter 2 – Study Area Description

Chapter 3 – Geomorphology And Sediment Cones   

Chapter 4 – Environmental Resources   

Chapter 5 – Problems And Opportunities   


Chapter 7 – References   

Chapter 8 – Appendices 
 
Appendix A    
Observation Notes On Sediment Cones  
 
Appendix B    
The University Of Texas Center For Space Research Summary Information    
Map Compilation Procedures    
Summary Information About Mapped Features    
Project Findings    
Appendix C   

Plant Species Found By Engel-Wilson And Ohmart In 1977    

                    Figures

Figure 1 - Map showing area of the Forgotten River    
Figure 3 - Candelaria IBWC Gage upstream of Capote Creek and Candelaria, Texas, January 2007.  Note aggradation from influence of San Antonio Diversion Dam (Mexican) just downstream and San Antonio arroyo confluence just upstream.    
Figure 4 - Confluence of the Green River with the Rio Grande (42 river miles downstream of Indian Hot Springs, Texas).  Note the sediment plug.  Photo February 2007    
Figure 5 - Upstream view of the Rio Grande and Green River confluence showing relative elevation of sediment plug and abrupt change in gradient of the Rio Grande; looking upstream.  Photo February 2007    
Figure 6 - Extreme drought and high flow years as recorded at the upper end of the study area, at the Fort Quitman gage    
Figure 7 - A myriad of small channels as a Result of sediment aggradation and salt cedar establishment characterize much of the Forgotten River Reach.  This segment lies upstream of Indian Hot Springs, (Photo taken January 2007).  Areas like these comprise thousands of acres and are responsible for attenuation of flows.    
Figure 8 - Below Candelaria, the Forgotten River Reach has a narrow, defined channel (foreground) at low flows, but transforms into a myriad of channels through an aggraded floodway at high flows, (Photo taken looking upstream  January 2007)    
Figure 9 - An avulsion out of a salt cedar-armored and aggraded channel into an adjacent Bermuda grass pasture upstream of Indian Hot Springs demonstrates the tentative nature of the channel through the Forgotten River Reach. (Photo taken January 2007)    
Figure 10 - Activity level distribution, overall    
Figure 11 - Distribution by activity level, US    
Figure 12 - Distribution by activity level, Mexico    
Figure 13 - Spatial distribution of "sediment cones" over study area    
Figure 14 - Confluence of the Rio Grande (to the right) and Rio Conchos (to the left) in Presidio County, Texas (Photo taken January 2007)    
Figure 15 - Large old-growth salt cedar trees on the Green River Valley Ranch, exceeding 20" Diameter Breast Height; February 2007.    
Figure 16 - The Rio Grande near Cecil's Pond Mitigation site - entrenched and displaying poor water quality, upstream of Haciendita, Texas looking downstream    
Figure 17 - A Corps' contractor examines the few remnants of over a thousand Cottonwoods and Willows that were planted in 1985 at Cecil's Pond Mitigation Site - Note the artificial snag placed in 1985 and still standing on the far left.  (2007)    
Figure 18 - A Bermuda grass pasture being colonized with Salt cedar in southern Hudspeth County, Texas  (January 2007)    

                        Tables

Table 1 - Magnitude Of Floods Of Different Recurrences At El Paso And Upstream Of The Rio Conchos    
Table 2 - Impaired Status, TCEQ Segment ID 2307, Rio Grande Below Riverside Diversion Dam To The Convergence With The Rio Conchos    
Table 3 - Salt Cedar Occupied Area (Acres) In Floodplain, Fort Quitman To Haciendita, Texas (IBWC 1978)    
Table 4 - Areas Of Vegetation Types On The U.S. Side, Study Area, Forgotten River Reach, Rio Grande, Fort Quitman To Rio Conchos Confluence, 1977    
Table 5 - Acreage Of Vegetation Types Within The Study Area As Photo Interpreted By UTCSR From 2002 Landsat Data    
Table 6 - Federal And State Listed Species That May Occur In The Forgotten River Reach Of The Rio Grande, Texas    
Table 7 - Initial Iteration Of Forgotten River North Classes And Samples    
Table 8 - Final Iteration Of Forgotten River North Classes And Samples    
Table 9 - Initial Iteration Of Forgotten River South Classes And Samples    
Table 10 - Final Iteration Of Forgotten River South Classes And Samples    
Table 11 - Summary Of Mapped Features