of statutory law presently referred to as "the Federal Reclamation
Law" fills three thick volumes encompassing all or parts of hundreds
of individual public laws.
 The initial purpose of the Reclamation Act, which was an outgrowth
of the earlier Homestead and Desert Land Entry Acts, was to estab-
lish a program of Federal financial assistance for water resource
development projects which were necessary if settlers were to establish
irrigated farms on the arid public lands west of the hundredth merid-
ian. The Reclamation program was carried out initially by the Recla-
mation Service which is now the Bureau of Reclamation in the Depart-
ment of the Interior.
 The program has evolved through the decades and is now a major
water resource development program involving major river basins
and multi-purpose projects providing hydro-electric power, municipal
and industrial water supply, fish and wildlife conservation, flood con-
trol, and public recreation in addition to the original irrigation pur-
pose. Nevertheless, irrigated agriculture continues to be a principal
and substantial aspect of the Reclamation program. In 1977, the
latest year of record, the Reclamation program supplied a full water
supply to nearly 5 million acres and a partial or "supplementary"
water supply to over 6 million additional acres. This acreage is dis-
tributed over about 176 separate Reclamation projects and about
146,000 individual farms. It represents about 3 percent of the Nation's
farmland and 25 percent of its irrigated farmland. The gross value of
crops from Reclamation farms in 1977 was about $4.4 billion.
 Under modern Reclamation Law the irrigation water users sign
contracts with the Secretary of the Interior agreeing to repay the
portion of the project investment costs allocated to the irrigation
function over a fixed period (usually 40 years) without interest. In
most instances, moreover, the repayment is limited to an amount less
than the full irrigation allocation which is the computed "repayment
capacity" of the farmers, and the costs in excess of that capability are
returned to the Treasury by electric power or municipal water reve-
nues from Bureau projects.
 From the outset of the Reclamation program, and up to the most
recent project authorizations, one consideration of Federal assistance
to irrigated agriculture has been the "acreage limitation" concept. The
original limitation was stated as follows in Section 5 of the Act of
1902:
 No right to the use of water for land in private ownership
 shall be sold for a tract exceeding 160 acres to any one land-
 owner, and no such sale shall be made to any landowner unless
 he be an actual bona fide resident on such land. . .
 The amount of land was a direct extrapolation of the limit on a
homestead entry, and projects which were built to irrigate public
lands involved homesteading provisions for new settlers as well as
project repayment.
 Over the 77 years of the Reclamation program, the acreage limita-
tion provision has been restated in statutes on numerous occasions and
several statutory modifications, amplifications and specific exemptions
have been enacted. Moreover, administrative practices in the imple-