Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

• Description: Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico
• State: CO
• State: NM
• Author: Abbott, P. O.; Geldon, Arthur; Cain, Doug; Hall, Alan; Edelmann, Patrick
• Title: Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico
• Water Supply Pro - Doc Type: Publication

5.0 SURFACE WATER -- Continued
5.4 Flood Flow
5.4.1 Floods
Flash Flooding Is a Problem
Floods result from intense thunderstorms during April through August and
may cause considerable damage and loss of life.
Thunderstorms produce floods generally during April
through August when prevailing winds from the southeast
bring moisture -laden air masses up against the mountains.
East - trending highlands such as the Raton Mesa cause
localized orographic lifting, resulting in floods such as
those in May 1955 and June 1965. These storms have been
described in U.S. Geological Survey Water - Supply Papers,
"Floods of May 1955 in Colorado and New Mexico"
(Vaudrey, 1960) and "Floods of June 1965 in the Arkansas
River basin, Colorado, Kansas, and New Mexico" (Snipes
and oti"iers, 1974). The greatest rainfall recorded during
the 1955 storm was 13.59 inches in 48 hours at Lake
Maloya, N. Mex.
A storm cell was located immediately west of Raton,
N. Mex., in June 1965 (fig. 5.4.1 -1). At the airport in
Raton, N. Mex., on June 17, 1965, 5.52 inches of rainfall
was recorded between 1700 and 2200 hours; 2.32 inches of
this fell between 1900 and 2000 hours. The total rainfall
during this storm was more than 10 inches (fig. 5.4.1 -2). A
rapid response in flood discharge of the Canadian River at
Hebron, N. Mex. (fig. 5.4.1 -2), resulted from each addi-
tional increment of rainfall at Raton.
Methods of estimating flood frequencies for basins in
the area vary according to the size of the basin and the type
of available information upon which the estimation is to be
based. Equations for estimating the flood frequency of
small (0.5't6 15 s'puare miles) ungaged sites on unregulated
streams in the Arkansas River basin in Colorado are
described by Livingston (1981). For larger ungaged drain-
age basins and for regionalization of gaged basins in
Colorado, methods are described by McCain and Jarrett
(1976). Techniques for estimating flood discharges for
unregulated streams in New Mexico are described by
Thomas and Gold (1982).
The equations for estimating flood magnitudes for
return intervals of 10 years (Qto), 50 years (Q50), and 100
years (Q1 0) are presented below for the various methods.
The equations developed by Livingston (1981) for small
streams in Colorado are:
Standard error
of estimate,
Equation in percent
Q10 = 525 AE .68 47
Q50 = 1,280 AEo'17 40
Qtoo = 1,680 AEo.82 37
where AE is the effective drainage area, in square miles.
44
The regionalized equations for larger streams in
Colorado developed by McCain and Jarrett (1976) are:
Standard error
of estimate,
Equation in percent
Q10= 144A' SBO .336 31
Q50 = 891 A0.482 SBo.154 24
Qtoo
= 1,770 A0.463 SBo.086 28
where A is total area of the drainage basin contributing to
flood discharges, in square miles, and SB is basin (channel)
slope, in feet per mile, measured between two points along
the main channel - -one of which is located at 10 percent of
the channel length and the other at 85 percent of the
channel length from the site of interest to the basin divide.
The equations developed by Thomas and Gold (1982)
for streams in New Mexico are:
Standard error
of estimate,
Equation in percent
Qlo = 3.88 x 10 A ' 4 (Sa /1,000)- ' 90
Q50 = 2.01 x 105 Ao.ao3 (Sa /1,000)-3'18 99
Q100 = 3.54 x 105 Ao.3s9 (Sa /1,000) -3'32 102
where A is the contributing drainage area, in square miles,
and Sa is site elevation, in feet above sea level.
As all the above equations were developed by regres-
sion analysis for hydrophysiographic regions using data
from sites for the respective states. under study, it is not
surprising that the equations developed are not precisely
applicable to an area such as Area 61 located north and
south of the State boundary. It has been determined that a
mean of the results of equations developed for Colorado
and those developed for New Mexico give reasonable peak
flow values for Area 61. For areas 15 square miles and
smaller in size, an average of the Livingston equation
results and the Thomas and Gold equation results needs to
be used. For areas larger than 15 square miles, the average
of the values computed by the McCain and Jarrett equation
and by the Thomas and Gold equation needs to be used.
The standard error of estimate probably is somewhere
between the values given for each set of equations of a
specified recurrence interval.