Southwestern States Flood and Drought Summaries
The most significant floods and droughts in New Mexico are listed chronologically in Table 1. The floods listed are those having recurrence intervals greater than 25 years; the droughts listed are those having recurrence intervals greater than 10 years. Records from 53 streamflow-gaging stations were used to determine the duration, areal extent, and seventy of floods; records from 17 gaging stations were used to determine the same characteristics for droughts. Streamflow data are collected, stored, and reported by water year (a water year is the 12-month period from October 1 through September 30 and is identified by the calendar year in which it ends).
|Flood or Drought||Date||Area Affected||Recurrence Interval (in years)||Remarks|
|Flood||Sept. 29, 1904||Northern, eastern, and northeastern parts of the State.||>100||Intense, widespread rainfall. Loss of lives and livestock; property damage, $ 1 million.|
|Flood||Oct. 6, 1911||Animas and San Juan Rivers||>100||Intense, localized rainfall.|
|Flood||June 29, 1927||Animas and San Juan Rivers||>100||Intense, localized rainfall.|
|Drought||1931- 41||Statewide||10 to >25||Moderate conditions in isolated areas in southwest and northern mountains. Sever conditions elsewhere.|
|Flood||Sept. 23, 1941||Southwest-central, southeast-central, and south-central parts of State.||50 to >100||Widespread rainfall.|
|Flood||Apr. 24, 1942||Rio Grande||>100||Intense, localized rainfall.|
|Flood||Sept. 1, 1942||Canadian and Pecos Rivers and central New Mexico||25 to >75||Most severe in lower reaches of streams. Moderately widespread rainfall.|
|Drought||1942-79||Statewide||>25||Moderate conditions in northeast and northwest. Severe conditions elsewhere.|
|Flood||June 17, 1965||Northeastern. southeastern, and parts of northern areas of State.||25 to >100||Hurricane from Gulf of Mexico. Intense, widespread rainfall. Damage, tens of millions of dollars.|
|Flood||Dec. 19, 1978||Gila River||75 to 100||Intense, localized rainfall.|
|Flood||June 9, 1988||Vermejo River||75 to 100||Intense, localized rainfall.|
From the gaging stations studied, six were selected to depict floods and six were selected to depict droughts: three of the gaging stations were used for both analyses. The gaging stations are located on largely unregulated streams and were selected on the basis of areal distribution, diversity of basin size, and hydrologic setting. The existence of substantial regulation eliminated from consideration the following major rivers: the San Juan, Pecos. and Canadian Rivers and the Rio Grande. Long-term trends in periods of declining streamflows may be discerned from gaging-station records for the regulated streams, but individual droughts are difficult to define.
Figure 1. Areal Extent of Floods in New Mexico. Click on image to view a larger version.
The areal extent and severity of major floods are shown in Figure 1. Two large floods affecting the eastern part of the State were those of 1904 and June 17, 1965. In 1904, few gaging stations were in operation in New Mexico. Consequently, the period of record for the six gaging stations used to depict floods does not include the 1904 flood; however, other stations in operation recorded streamflow conditions during the 1904,1941,1942, and 1965 floods. Records from those stations indicate that the 1904 flood peak discharges generally were larger than those of the 1965 flood. Major damage was reported along the Pecos, Canadian, Cimarron, Red, Gallinas, Mora, Sapello, and Santa Fe Rivers; along Rayado and Manuelitas Creeks; and along the Rio Grande (Monk,1904). Information from eyewitnesses provided a basis for determining flood damage, which was estimated to be at least $ 1 million; of this amount, one-half was damage to railroads (Monk, 1904).
The flood of September 23, 1941, affected mostly the central part of the State. On September 23, 1941, the peak discharge of the Rio Puerco near Bernardo was 18,800 ft3/s(cubic feet per second). Peak discharges of most streams in the affected areas had recurrence intervals greater than 50 years. Other areas that had peak discharges with recurrence intervals of less than 50 years probably also were affected by the flood; however, records do not exist to document streamflow conditions.
The September 1, 1942, flood affected the central and eastern parts of the State and, to a lesser extent, the northeastern part. Streamflow records indicate that peak discharges at most gaging stations had recurrence intervals of 50-75 years. On September 1, 1942, the peak discharge of the Pecos River near Puerto de Luna was 48,600 ft3/s, which has a recurrence interval greater than 100 years. Accounts by local residents indicate that the 1942 flood was of lesser magnitude than the 1904 flood.
The flood of June 17, 1965, likewise was not as severe as the flood of 1904. There was no loss of human life, but property damage was estimated to be tens of millions of dollars (Snipes and others, 1974). Streamflow records indicate that the 1965 flood had a recurrence interval greater than 100 years in many areas across the eastern part of the State. For example, on June 17, 1965, the peak discharge of the Vermejo River near Dawson was 12,600 ft3/s, the peak discharge of record for that gaging station. This flood occurred during a major drought but did not have an appreciable effect on the drought because of the relatively short duration of the increased streamflows.
In addition to the floods previously described, severe flooding occurred in parts of the State on October 6, 1911 (water year 1912), June 29,1927, April 24,1942, December 19,1978 (water year 1979), and June 9, 1988. In those instances, however, flooding was localized and did not cause widespread damage. The peak discharge of the October 6,1911, flood has remained undetermined. However, the peak stage of the Animas River at Farmington during the 1911 flood was about twice the stage of the flood of June 29, 1927, which had a peak discharge of about 25,000 ft3/s. The recurrence interval for the flood of June 29, 1927, on the Animas and San Juan Rivers exceeded 100 years, as did that of the flood of April 24, 1942, on the Rio Grande in the central part of the State. Major flooding on the Gila River near Redrock on December 19, 1978, resulted in a peak discharge of 48,800 ft3/s. The flood of June 9, 1988, on the Vermejo River near Dawson had a peak discharge of about 10,400 ft3/s. Floods of both the Gila River near Redrock on December 19, 1978, and the Vermejo River near Dawson on June 9, 1988, had recurrence intervals between 75 and 100 years.
Figure 2. Areal Extent of Droughts in New Mexico. Click on image to view a larger version.
Droughts are common in New Mexico. The normally meager annual precipitation causes extended periods of scant flow in the State's unregulated rivers. Streamflow records can be used as one means to determine the duration and areal extent of droughts.
The areal extent and severity of major droughts in New Mexico are shown in Figure 2. The areas of drought delineated on the maps are based on data from gaging stations statewide. However, only six gaging stations are used to describe the general severity of droughts.
The annual departure from average stream discharge for any year is the difference between the average discharge for that year, which is determined from daily streamflow records, and the average discharge for the period of record. Records for some gaging stations indicate an almost continuous deficiency of streamflow throughout a given drought, whereas records for other stations may indicate 1 or more years when streamflow was average or greater than average during a drought.
Such short-term reversals in trend can indicate two separate droughts or a short recovery period within the major drought. A study that employed a 5-year moving average to analyze streamflow within the Rio Grande basin showed that such reversals did not constitute recovery periods (Waltemeyer. 1987). Therefore, in this study. Streamflow deficiencies were computed for each drought within the longer drought period to determine a recurrence interval.
Major long-term droughts occurred in New Mexico during 1931-41 and 1942-79. The duration of the two droughts differed among streamflow-gaging stations, and the dates represent the earliest beginning date and latest ending date common to most stations. For example, at five of the six gaging stations, the 1942-79 drought ended in 1979, but the start of the drought ranged from 1942 to 1948. Most gaging-station records from the statewide network indicate a sustained drought from 1950 to 1979.
The drought of 1931-41 affected the entire State. The Dust Bowl conditions in the Plains States probably are the most memorable aspect of this drought. Stream low deficiencies in New Mexico during this period were significant but less severe than those during the subsequent drought. Streamflow records for the Vermejo River near Dawson, Rio Hondo near Valdez , and Pecos River near Pecos, indicate that the drought had recurrence intervals of 10-25 years in north-central New Mexico. In most of the State, however, the drought was severe and had a recurrence interval greater than 25 years. Nevertheless, no annual precipitation minimums were recorded at any weather station in the vicinity of the gaging stations during the 1931-41 drought.
An extended period of deficient stream flow affecting all of New Mexico lasted from the early 1940's to late 1970's (Fig. 2). The 1942-79 drought greatly affected non-irrigated agricultural areas in New Mexico. Although farmers in the State have minimized the effect of drought on their crops by irrigating, dryland farming is still practiced for some crops, such as wheat. Wheat production in the 1950's was the smallest since 1909 (Cockril, 1959). By the end of the 1950's, about 2,000 wells had been drilled to supplement surface-water irrigation allotments, which had been decreased in response to the drought (Wayne Cunningham Elephant Butte Irrigation District, oral communication, 1988) Precipitation records indicate the severity of the 1942-79 drought annual precipitation minimums were recorded at Albuquerque (4.06 inches in 1956), Farmington (4.07 inches in 1950), Carlsbad (4.40 inches in 1956), and Glenwood (6.90 inches in 1956) (Kunkel, 1984).
During the drought, streamflow deficiencies were recorded at all six gaging stations, and periods of greater than average annual departures generally did not exceed about 2 years. At Ute Creek near Logan, however, periods in which sustained streamflow deficiencies exceeded surpluses did not begin until 1961.
Cockril,P.W., 1959, A statistical history of crop and livestock production in New Mexico: New Mexico State University, New Mexico Agricultural Experiment Station Bulletin 438, 35p.
Kunkel,K.E., 1984, Temperature and precipitation summaries for selected New Mexico locations: New Mexico Department of Agriculture, Climate report, 190p.
Monk,G.B., 1904 Report of floods in New Mexico during September and October 1904: U.S. Geological Survey files, 25p.
Snipes,R.J., and others, 1974, Floods of June 1965 in Arkansas River basin, Colorado, Kansas, and New Mexico: U.S. Geological Survey Water-Supply Paper 1850-D, 97p.
Waltemeyer,S.D., 1986, Techniques for estimating flood-flow frequency for unregulated streams in New Mexico: U.S. Geological Survey Water-Resources Investigations Report 86- 4104, 56p.