LAWSON

LAWSON 08.01. 1879 Washington DC/USA 21.12. 1963 El Paso TX/USA Lawrence Milton Lawson studied engineering at the Leland Stanford University, Palo Alto CA. He was in 1901 assistant engineer of San Francisco water supply, then hydrologic aide of the US Geological Survey, from 1903 to 1904 in charge of topographic surveys of Colorado River, then from 1905 to 1911 assistant engineer of the Yuma Project, from 1912 to 1915 project engineer of the Rio Grande Project, El Paso TX, returning until 1917 as project engineer to the Yuma Project in charge of river control and canal construction, from when he was until 1926 in charge of the Rio Grande Federal Irrigation Project. He was appointed American Commissioner of the International Boundary Commission between Mexico and the USA in 1927, and there was an engineer of the US Department of State in negotiations and constructions of the Rio Grande International Rectification Project, the Nogales Flood Control Project, and the Lower Rio Grande Flood Control Project. He was instrumental in the US-Mexican Water Treaty providing for utilization of waters of boundary streams, construction of storage dams on Rio Grande, and flood control, channelization and drainage, which was ratified in 1944. The 1934 paper of Lawson describes the flood control and river rectification operations along the boundary line that have been seriously menaced in the past by uncontrolled floodwater, then improved by the Intl. Boundary Commission. This Commission also formulated practical steps in constructive efforts between the two countries. The work was supported by Joseph B. Lippincott (1864-1942), among others. Lawson served with 27 years longest as US Section Commissioner; he found wide recognition as tamer of Rio Grande. In the early 1940s he provided a stable river channel, protecting residents from floods, thereby presiding over the construction of the American Dam at El Paso, diverting water from Rio Grande into the US canal. The 1944 Water Treaty certainly was his greatest accomplishment, leading to the completion of the Falcon Dam in 1953. Joseph F. Friedkin (1909-2008) stated: ‘Lawson has left us with a great inspiration’. Anonymous (1948). Lawson, Lawrence M. Who’s who in engineering 6: 1167. Lewis: New York. Lawson, L.M. (1929). Discussion of Silting of the lake at Austin TX. Trans. ASCE 93: 1690-1693. Lawson, L.M. (1934). Mexico and United States join in border flood control. Engineering News-Record 113(Oct.04): 419-423. Vigil, C. (2012). The canalization of the Rio Grande: A brief history. New Mexico Journal of Science 46(12): 249-259. https://www.ibwc.state.gov/About_Us/Commish_History.html P

LEACH H.R. 14.07. 1891 Saginaw MI/USA 24.06. 1941 Fort Myer VA/USA Harry Raymond Leach graduated as a civil engineer from the University of Michigan, Ann Arbor MI, in 1916. He stayed there another year assisting Horace Williams King (1874-1951) in preparing his notable Handbook of hydraulics. He then was employed by Robert Elmer Horton (1875-1945) at Albany NY. In 1918 Leach joined the US Army. He was trained in the US Meteorological Section in the technique of upper-air sounding in Missouri and North Carolina. In 1919, Leach undertook a floods study of Saginaw County and then also conducted a study of storage possibilities in watersheds of Utah State. From 1920 to 1933, he collaborated again with Horton as principal assistant, conducting studies in hydraulics and hydrology for hydroelectric and water supply works. Leach was employed in 1934 by the State of New Hampshire, Concord NH, supervising the establishment of recreational centers. In 1935 he became affiliated with the Soil Conservation Service SCS of the US Department of Agriculture, devoting now his full time to hydraulics and hydrology. He had hoped to bring into orderly array the knowledge he had accumulated during the busy years of his professional practice, contributing thereby a number of papers to the engineering community. A long illness and his untimely death at age fifty prevented the attainment of this goal, however. The ‘Leach method’ for computing backwater curves was proposed in his 1919 paper. A river reach is thereby divided into suitable portions, with its local conveyance consisting of typical cross-sectional area times the roughness coefficient. Starting from a boundary condition, and using flow diagrams, the water surface elevation of a neighbouring section may be determined. Other works published around 1920 relate to devices of irrigation engineering and the variation of the roughness coefficient in rivers. Anonymous (1916). H.R. Leach. Michiganenisan yearbook: 165. Ann Arbour. P Anonymous (1944). Harry Raymond Leach. Trans. ASCE 109: 1500-1502. Jacob, C.C., Leach, H.R. (1931). Field experiments on a practical irrigation rating box. Engineering News-Record 88(13): 530-531. Leach, H.R. (1919). New methods for the solution of backwater problems. Engineering News-Record 82(16): 768-770. Leach, H.R. (1919). Variation of roughness coefficient in Manning and Kutter formulas. Engineering News-Record 82(11): 536-538. Leach, H.R. (1931). Disc. on Effect of turbulence on current meters. Trans. ASCE 95: 816-826.