Vigil Network Site: Cañada de la Cueva Headcut Near Galisteo, New Mexico, U.S.A.
By Harold E. Malde
Cañada de la Cueva is an ephemeral stream 7 miles long that flows southwestward to Galisteo Creek 4 miles upstream from Cerrillos, N. Mex. (fig. 3). The upper reach of this stream dissects the western edge of the Ancha Formation, a bolson deposit of poorly sorted, uncemented gravel, sand, and silt. A wier and rain gage have been installed by the U.S. Geological Survey (Surface Water Branch, Santa Fe, N. Mex.) on Cañada de la Cueva at the graded road between Cerrillos and Galisteo about 4 1/2 miles above the mouth. The headcut described here is 1 mile upstream from the wier and 1 1/2 miles downstream from the drainage divide (figs. 1, 2).
Because of the opportunity to relate future changes in the headcut to measurement of discharge and precipitation, the headcut was selected for long-term observation as part of the Vigil Network.
This site is the head of a gully 4.2 miles northwest of Galisteo, N. Mex., NW 1/4 SW 1/4 sec. 16, T. 14 N., R. 9 E. (lat 35°26'24", long 105°59'49"). This part of Cañada de la Cueva is shown on the U.S. Geological Survey topographic map, "Galisteo, N. Mex., 1966," scale 1:24,000, and on topographic map, "Santa Fe, N. Mex., 1964," scale 1:250,000. The lower reach of Cañada de la Cueva is shown on topographic map, "Madrid, N. Mex., 1961," scale 1:62,500, and on topographic map, "Albuquerque, N. Mex., 1963," scale 1:250,000. The headcut, the wier, and the upper reach of Cañada de la Cueva are on property owned by Mr. Bluford Thornton, who resides 3 miles east and who manages the property as a cattle ranch.
The valley of Cañada de la Cueva upstream from the headcut is a broad, undissected swale dominated by grama grass (Bouteloua) and by scattered juniper (Juniperus). (See figs. 4, 5, which are black-and-white photographs by H. E. Malde, identified by field numbers 70 M 119 and 70 M 120; Ektachrome transparency 4 x 5 inches, and black-and-white negative 4 x 5 inches, for each.) The floor of the swale has rather abundant snakeweed (Gutierrezia sarothrae), a shrub that grows about 1 foot high. Sparse rabbitbrush (Chrysothamus), a shrub about 3 feet high, grows near the headcut and in the channel. Rare clumps of Cholla are spaced several hundred feet apart.
The altitude of the channel at the headcut is about 6,190 feet, and the head of the drainage divide 1 1/2 miles northeast is at an altitude of 6,380 feet. The relief ratio is, therefore, 0.024. Precipitation averages about 12 inches per year, of which the greater part falls as rain in summer.
To reach the Cañada de la Cueva headcut, one may start from Galisteo, proceed 4 miles northwest on a graded road, turn northeast about 1 mile on an unimproved road, and then walk west 1 mile to the headcut. Alternatively, one may continue on the graded road to the wier on Cañada de la Cueva and there walk upstream 1 mile to the headcut.
The permanent reference points at the headcut are 7 rods driven into the ground and protruding a little less than a foot above ground (tables 1, 2). Of these, two are "Copperweld" rods with brass caps imprinted with the marks "70 M 117" and "70 M 118" as indicated on the attached planetable map (fig. 1). The others, A through E, are half an inch diameter rods of reinforcing steel. A supplemental steel rod is placed in the channel at station 0+00. In addition, nine places on the vertical wall of the headcut are marked by erosion pins, each consisting of a 10-inch nail put through a washer and driven flush with the wall face at a level 2 feet below the ground surface. Increments of erosion can be determined by repeated measurements of the position of each nail with respect to the wall, the nails being again driven flush after each observation.
A field survey of the Cañada de la Cueva headcut was made on August 17-19, 1970. Elevations from this survey are listed in the attached series of tables (tables 2, 3, 4, 5, 6). The survey consists of a planetable map of the outline of the headcut and three cross-sectional profiles. In addition, a longitudinal profile along the channel floor was surveyed over a distance of 335 feet, beginning at a rod driven in the channel floor on the line between rods 70 M 117 and 70 M 118. Because of differences in elevation that arise from variable placement of the stadia rod on the ground surface, the measurements of elevations are judged to be repeatable with an accuracy of 0.1 foot. The position of the headcut outline can be read from the planetable map to an accuracy of 1 foot.