FLOOD CONTROL AMAFCA The Albuquerque Metropolitan Arroyo Flood Control Authority (AMAFCA) was created in 1963 by the New Mexico Legislature with specific responsibility for flooding problems in greater Albuquerque. AMAFCA AMAFCAs purpose is to prevent injury or loss of life, and to eliminate or minimize property damage. AMAFCA does this by building and maintaining flood control structures which help alleviate the problem. Traditional flood control measures focus on protection of existing developments through construction of dams (to hold water back) and channels (to divert or confine flows). AMAFCA The first mission of AMAFCA was to be the local sponsor for construction of two very large federally-funded projects, the North and South Diversion Channels (NDC and SDC), which were built by the Army Corps of Engineers. The NDC drains Northeast Albuquerque and can carry 44,000 cubic feet per second at its outlet. The smaller SDC protects the Southeast Valley by intercepting flows from Southeast Albuquerque and the Tijeras Arroyo. AMAFCA today is still responsible for those two main flood control structures. Arroyos in Albuquerque Albuquerques drainage consists of natural drainage systems and concrete-lined arroyos. These arroyos carry runoff from the Sandia Mountains and West Mesa to the Rio Grande and are dry most of the year. They flow most heavily in the summer when the warm, moist, tropical air masses from southern California and the Gulf of Mexico collide over the Sandias. Flood Photos in Albuquerque Current Projects at UNM The Hydraulics Lab at UNM tests different pipe diamater with 30, 45, and 90 angles to the downstream flow. At low flow rates 30 angle resulted in more diverted flow. As flows were increased, wave action increased, and the angle of diversion no longer made much difference in the amount of diverted flow. Current Projects at UNM Q=2500 cm3/s Q=6700 cm3/s Q=14,600 cm3/s Based on observation and flow measurement, the tapered vane results in increased diversion with no undesirable hydraulics. The rate of taper and height of the vane should be further investigated. Computed Flow Pattern of 45angled lateral diversion with tapered vane. SOURCES