Ground water in North America
The fast-growing demands on this natural resource expose a need to resolve many hydrologic unknowns.
Science↗
Geology topics
Harold E. Thomas
Publications and source records attributed to Harold E. Thomas.
Hydrology and hydrogeology of Navajo Lake, Kane County, Utah
Navajo Lake, whose entire outflow disappears underground, is on the high Markagurit Plateau where the average annual precipitation is more than 30 inches. It nestles among the headwaters of several streams that flow into arid regions where competition for municipal, industrial, and irrigation water sup- plies is very keen. Several proposals for additional development and use of the water of Navajo Lake have led to controversies and raised questions in regard to the total water supply and its disposition, and to the effect of the proposed projects on existing water rights. This report summarizes the results of an investigation of the water supply of Navajo Lake and the present disposition of that supply.
Utah↗
Causes of depletion of the Pecos River in New Mexico
Explore the source record for details and available documents.
Water Supply Paper↗
Hydrology and water law: what is their future common ground?
We live in an age of social and economic evolution--evolution so deep reaching and rapid it constitutes ad revolution in numerous fields of human concern. Long-standing concepts of what is appropriate and orderly face drastic modification if they are to survive. To this situation the principles of applied hydrology and the tenets of water law are no exceptions. Their common ground, incomplete in the past, becomes tenuous when projected into the future. To hydrologists it is common knowledge that the Nation has some trouble spots tin water supply, occasioned by burgeoning population, by standards of living that seem luxurious to other peoples if not to us, and by tremendously dynamic industry whose voracious thirst for water seems insatiable. Seldom is the "trouble" a mere lack of water in a quantity sufficient to serve all real needs; rather, water usually is available only part of the time, at greater-than-customary cost, or under competition among several potential uses. We can expect only that such spots will increase in number and in geographic reach.
Open-File Report↗
Water rights in areas of ground-water mining
Ground-water mining, the progressive depletion of storage in a ground-water reservoir, has been going on for several years in some areas, chiefly in the Southwestern States. In some of these States a water right is based on ownership of land overlying the ground-water reservoir and does not depend upon putting the water to use; in some States a right is based upon priority of appropriation and use and may be forfeited if the water is allowed to go unused for a specified period, but ownership of land is not essential; and in several States both these doctrines or modifications thereof are accepted, and each applies to certain classes of water or to certain conditions of development. Experience to date indicates that a cure for ground-water mining does not necessarily depend upon the water-rights doctrine that is accepted in the area. Indeed, some recent court decisions have incorporated both the areal factor of the landownership doctrines and the time factor of the appropriation doctrine. Overdraft can be eliminated if water is available from another source to replace some of the water taken from the affected aquifer. In areas where no alternate source of supply is available at reasonable cost, public opinion so far appears to favor treating ground water as a nonrenewable resource comparable to petroleum and metals, and mining it until the supply is exhausted, rather than curbing the withdrawals at an earlier date.
Circular↗
First Fourteen Years of Lake Mead
This circular summarizes the results of recent studies of Lake Mead and its environs. Area-capacity tables, prepared on the basis of a hydrographic survey of the lake in 1948-49, show that the capacity of the reservoir was reduced 4.9 percent during the first 14 years after Hoover Dam was completed, but the usable capacity was reduced only 3.2 percent. Practically all of this reduction was caused by accumulation of sediment in the reservoir. Studies of inflow and outflow indicate that the reservoir has a total storage capacity about 12 percent greater than that shown by the area-capacity table, because of 'bank' storage, or ground-water storage in the bottom and sides of the reservoir. Thus the total capacity in 1949 was greater than the quantity shown by the original area-capacity table, even though large quantities of sediment had been deposited in the reservoir during the 14 years. According to computations of the volume and weight of the accumulated sediment, about 2,000 million tons were deposited in the reservoir by the Colorado River in 14 years; this is within 2 percent of the amount calculated from measurements of the suspended sediment carried by the in flowing rivers. It is estimated that the sediment capacity of the reservoir, when filled to the level of the permanent spillway crest, is about 75,000 million tons. The sediment contributed by the Colorado River averages about 45 percent sand and 55 percent silt and clay. If the sediment carried by the river in the years 1926-50 represents the long-term average rate of accumulation in Lake Mead, it will be a century before the sediment at the dam reaches the level of the lowest gates in the intake towers, and more than 4 centuries before the reservoir is filled with sediment to the level of the permanent spillway crest. The rate of sedimentation since the first year of Lake Mead (1935) has been about 20 percent lower, and if that rate continues in the future, the life of the reservoir will be correspondingly greater. Construction of upstream reservoirs to capture some of the inflowing sediment, or transportation of sediment in the outflow through Hoover Dam, would also increase the life of the reservoir. In the first 12 years of Lake Mead, the dissolved mineral matter in the outflowing water was significantly greater than the average in the in flowing water, owing in part to solution of gypsum and rock salt from the bed of the reservoir. Currently the increased dissolved solids in the outflowing water can be accounted for almost entirely by evaporation from the reservoir, which is about 5 fo 7 percent of the annual inflow. The water from Lake Mead is habitually of better quality than that diverted from the river for irrigation prior to regulation by Hoover Dam, because it represents an average of the poor water of low stages and the excellent water from melting snow. Geodetic surveys of the Lake Mead area show that the weight of water has caused subsidence of the earth's crust amounting to about 120 millimeter at Hoover Dam, and an even greater amount in the principal area of storage in the reservoir.
Circular↗
Manganese in a thermal spring in west-central Utah
The hot spring north of Delta, Utah, is of particular interest because it has yielded commercial manganese ore; 715 tons of manganese oxide ore that averaged 20% manganese and 0.26% sulphur is recorded. The deposits occur as a thin bed and as lenses and nodules in a dome about 1,600 feet across and 15 feet high that has been formed subsequent to the dessication of Pleistocene Lake Bonneville. The alkaline hot waters, which reach temperatures of 182 degrees F. and have a total discharge of over 1,200 gallons a minute, average 3,900 parts per million in dissolved solids, with NaCl, CaSO 4 , MgCl 2 , and CaCO 3 . Five complete analyses show a manganese content of from 0 to 1.2 parts per million. Nevertheless, no appreciable manganese seems to be precipitating at present. The bed of manganese and iron oxides is scarcely more than a foot thick and is mostly covered by porous calcite. The ore is a porous aggregate of psilomelane and pyrolusite in which the vugs are lined with limonite. These minerals have been formed through the action of hot alkaline solutions over a long period; the original mineral was probably wad. The barium oxide is believed to be chemically combined with the manganese oxides. Probably all these materials have been leached from underlying rocks or deposits by hot circulating groundwaters and may not have a magmatic source.
Utah↗