| Show I BUILDING A BETTER WORLD I NEW MILLION FACILITY A MONUMENTAL STEP IN FLOOD CONTROL How do you handle the problem of periodic floodIng flooding flooding flood flood- ing That question has plagued many municipal officials officials officials of of- and engineers over the years A monumental step toward solving this problem occurred this month in Mexico City with the inauguration of the worlds world's largest deep drainage drainage drainage drain drain- age system President Luis Echeverria dedicated the million project which required the labor of workers and eight years for completion The mile 60 network of tunnels interceptors and collectors is located at depths up to feet below heft be- be ft JR lo low w the sura surface sur sur- rS face a cew ce of this V bU teeming metropolis me me- S 1 e 0 of f Echeverria eight million people Engineers decided it was was' was necessary necessary to go to this thi I depth to avoid effects of the notorious sinking of the ther r I 1 ity This required drilling and nd working through a dozen dozen dozen doz doz- en en diff different rent types of r rock k kand and soil and adapting unique techniques to cope with wah problems encountered along the way The new project is designed design design- ed to simultaneously dispose of sewerage and storm wa wa- Over the past 50 years Mexico City has had an average annual rainfall of 28 inches but this figure is deceptive since most of it falls between June and September The system has a capacity capacity ca ca- to evacuate cubic feet of water per second and after treatment eject it into the lying lower-lying areas of Hidalgo state for irrigation purposes I j f S1 M wi e JI A t 1 Ii Innovative Flood Control Project Completed The three main tunnels running south north-south under the city have a diameter of feet feel sufficient to house two lanes of metropolitan auto traffic These tunnels have an inside covering of 45 million feet of steel and concrete specially treated to withstand effects of sulphates in waste waters Mayor Octavio hailed the project as the most monumental engineering engineer engineering engineer engineer- ing job in the history of Mexico City The mile-high mile Valley of Mexico surrounded surround ed by towering mountains lacks natural drainage outlets outlets out out- lets for heavy summer rains rains and has been plagued by flooding since pre pre times king of Texcoco built an mile 8 dike to control flood waters in 1449 and various Spanish viceroys added more during the year colonial period In 1900 President Porfirio Diaz inaugurated the Grand Drainage Canal and Tunnel which met the needs of the city's half million population Explosive growth of the city in recent years brought new and more serious lems Proliferation of deep wells to meet industrial and domestic demands for water produced serious serious sinking sinking By 1959 the midtown area was the lowest part of the Valley of Mexico and seasonal seasonal seasonal sea sea- rains brought renewed renewed renewed renew renew- ed flooding Municipal authorities in installed installed installed in- in stalled a series series of pumping stations to augment the gravity flow drainage system but the system became increasingly increasingly in increasingly in- in inadequate Any failure in m the pumping system tem tern could have disastrous consequences Faced with this threat construction of the deep drainage system was ordered in 1967 Engineers said the new deep drainage system is deigned designed designed de de- signed to meet the needs of the metropolitan area until the year 2000 when they estimate the population will reach 15 m million |
