Post Flood Report: Record Rainfall and Flooding Events During September 2013 in New Mexico, Southeastern Colorado and Far West Texas Contributing Staff: Ariane O. Pinson, Climate Science Specialist Stephen K. Scissons, Hydraulic Engineer Stephen W. Brown, GeoSpatial Analyst Douglas E. Walther, GeoSpatial Analyst November 2014 Cover Photo: September 17, 2013. Looking Southwest at the Rio Grande at Bernardo (Courtesy of Civil Air Patrol). Post Flood Report, New Mexico, Southeast Colorado, and Far West Texas, September 2013 Table of Contents 1 - Introduction ............................................................................................................................... 1 1.1 Scope of this Report ......................................................................................................... 2 1.2 Authorization for this Report ........................................................................................... 2 1.3 Agencies and Scope of Services Provided ....................................................................... 3 1.4 Organization of this Report .............................................................................................. 3 1.5 A Note on Precipitation Gages as Compared to NEXRAD Precipitation Data ............... 3 2 - Overview of the 9-18 September 2013 Flood Event ................................................................. 5 2.1 Drought Context of the Flood Event .............................................................................. 17 2.2 Monsoon Context of the Flood Event ............................................................................ 18 2.3 The Contribution of Tropical Cyclones over Mexico .................................................... 19 3 - Flooding in Climate Context ................................................................................................... 21 3.1 Principle Causes of Major Flooding .............................................................................. 24 3.1.1 Spring Runoff Flooding .......................................................................................... 24 3.1.2 Tropical Cyclones / Cyclone Remnants Entrained in the NAM ............................. 26 3.2 Frequency of Tropical Cyclone Impacts to New Mexico .............................................. 29 3.2.1 East Pacific Basin Tropical Cyclones ..................................................................... 29 3.2.2 Atlantic Basin Tropical Cyclones ........................................................................... 29 3.3 Changing Extreme Event Frequencies Under a Changing Climate ............................... 30 3.3.1 Observed Trends ..................................................................................................... 30 3.3.2 Model Projections ................................................................................................... 31 3.3.3 Implications for Future Tropical Storm-Related Flood Events .............................. 31 4 - Rio Grande Basin..................................................................................................................... 33 4.1 Rio Grande Basin Overview .......................................................................................... 33 4.2 Meteorological Event in the Rio Grande Basin ............................................................. 34 4.3 Rainfall Data in the Rio Grande Basin ........................................................................... 36 4.4 Event Hydrology in the Rio Grande Basin .................................................................... 40 4.5 Flooding in the Rio Grande Basin .................................................................................. 46 4.5.1 Flooding in the Eastern Jemez Mountain Tributary Basins, NM ........................... 46 4.5.2 Flooding in the Vicinity of Truth or Consequences, NM ....................................... 50 4.5.3 Flooding in the Greater El Paso Region in NM and TX ......................................... 50 4.5.4 Flooding in Santa Clara, Grant County, NM .......................................................... 54 i Post Flood Report, New Mexico, Southeast Colorado, and Far West Texas, September 2013 4.5.5 Flooding Along the Rio Puerco in NM ................................................................... 54 4.5.6 Flooding Along the Lower Rio Chama, NM Below Abiquiu Dam ........................ 55 4.6 Reservoir Operations and Damages Prevented in the Rio Grande Basin ...................... 55 4.6.1 Cochiti Dam and Lake ............................................................................................ 55 4.6.2 Jemez Canyon Dam and Reservoir ......................................................................... 56 4.6.3 Galisteo Dam and Reservoir ................................................................................... 56 4.6.4 Flow Reductions ..................................................................................................... 57 4.7 USACE Flood Response Efforts in the Rio Grande Basin ............................................ 58 4.8 FEMA Damages Assessments in the Rio Grande Basin ................................................ 59 5 - Pecos Basin .............................................................................................................................. 60 5.1 Pecos Basin Overview .................................................................................................... 60 5.2 Meteorological Event in the Pecos Basin ....................................................................... 62 5.3 Rainfall Data in the Pecos Basin .................................................................................... 62 5.4 Event Hydrology in the Pecos Basin .............................................................................. 65 5.5 Flooding in the Pecos Basin ........................................................................................... 70 5.5.1 Flooding in Las Vegas, New Mexico ..................................................................... 70 5.5.2 Flooding near Puerto de Luna, New Mexico .......................................................... 74 5.5.3 Flooding north of Carlsbad, New Mexico .............................................................. 75 5.6 Reservoir Operations and Damages Prevented in the Pecos Basin ................................ 76 5.6.1 Santa Rosa Dam and Lake ...................................................................................... 76 5.6.2 Fort Sumner Dam and Lake .................................................................................... 77 5.6.3 Two Rivers Dam and Reservoir .............................................................................. 77 5.6.4 Brantley Dam and Reservoir ................................................................................... 77 5.6.5 Flow Reductions ..................................................................................................... 78 5.7 USACE Flood Response Efforts in the Pecos Basin ..................................................... 79 5.8 FEMA Damages Assessments in the Pecos Basin ......................................................... 80 6 - Upper Canadian River Basin ................................................................................................... 81 6.1 Upper Canadian River Basin Overview ......................................................................... 81 6.2 Meteorological Event in the Upper Canadian River Basin ............................................ 82 6.3 Rainfall Data in the Upper Canadian River Basin ......................................................... 82 6.4 Event Hydrology in the Upper Canadian River Basin ................................................... 83 6.5 Flooding in the Upper Canadian River Basin ................................................................ 86 6.6 Reservoir Operations and Damages Prevented in the Upper Canadian River Basin ..... 86 6.7 USACE Flood Response Efforts in the Upper Canadian River Basin ........................... 86 ii Post Flood Report, New Mexico, Southeast Colorado, and Far West Texas, September 2013 6.8 FEMA Damages Assessments in the Upper Canadian River Basin .............................. 86 7 - Upper Arkansas River Basin ................................................................................................... 87 7.1 Upper Arkansas River Basin Overview ......................................................................... 87 7.2 Meteorological Event in the Upper Arkansas River Basin ............................................ 88 7.3 Rainfall Data in the Upper Arkansas River Basin.......................................................... 88 7.4 Event Hydrology in the Upper Arkansas River Basin ................................................... 89 7.5 Flooding in the Upper Arkansas River Basin ................................................................ 96 7.6 Reservoir Operations and Damages Prevented in the Upper Arkansas River Basin ..... 98 7.7 USACE Flood Response Efforts in the Upper Arkansas River Basin ........................... 98 7.8 FEMA Damages Assessments in the Upper Arkansas River Basin............................... 99 8 - Upper San Juan River Basin .................................................................................................. 100 8.1 Upper San Juan River Basin Overview ........................................................................ 100 8.2 Meteorological