ASCE

For 2,000 years, Aqueducto de Segovia has been conveying drinking water from the Frio River to Segovia, approximately 18 kilometers away. Built under the reign of Roman emperor Trajan, the aqueduct is one of the most intact and best-preserved Roman engineering masterpieces. Roman engineers built the channel of the aqueduct with an average one percent gradient over its whole length.

Queretaro's aqueduct, in Central Mexico, is one of the most eloquent symbols of colonial Mexico. As one of the early major hydraulic engineering projects in North America, it defines the city both nationally and internationally. The aqueduct, designed in 1723 by Juan Antonio de Urrutia y Arana, Marquis of Villa del Villar del Aquila, was inspired by the aqueducts of Segovia, Merida and Tarragona in Spain. It began supplying clean water to the city in this arid region of Mexico on October 17, 1738.

The roman emperor Trajan ordered a new aqueduct be built to bring fresh water to Italy's Trastevere region and parts of Rome. The water is collected from five springs that feed the lake at Bracciano, and traverses over 25 miles into Rome. To maintain an even gradient, the aqueduct follows a meandering alignment through the countryside to avoid hills and major valleys. The water runs through an open-channel canal that is either arch-supported, at-grade, or underground.

This is one of the earliest uses of engineered water supply and irrigation systems in the United States. The first of eight original acequias was under construction in 1718 and two are still in operation. The remains of one are visible on the grounds of the Alamo. The Acequias of San Antonio are among the earliest engineered water supply and irrigation systems recorded in the United States. The Acequias served an integral role in the growth and stability of the San Antonio community for nearly 200 years.

Maine's heavy snows led turnpike maintenance personnel to bring "left-handed" snow plows into prominence. By using left-handed and traditional right-handed plows in tandem, they were able to distribute snow more evenly - an important advance that has been emulated by many highway maintenance crews across the country.

The Miami Conservancy District flood control project was the direct result of the disastrous flood of 1913, when waters from the Miami, Stillwater, and Mad rivers flooded Dayton and surrounding communities in the Miami Valley. More than 400 lives were lost and property damage exceeded $100 million. When Dayton flooded, great fires raged, adding to the devastation. Many believed that the area would never recover. 

The 1.6-mile Holland Tunnel was the first underwater vehicular crossing of the Hudson River and the first tunnel specifically designed for automobiles and trucks. It dramatically reduced the time required to traverse the Hudson River, a trip previously possible only by ferry. 

A major difficulty when tunneling beneath a river is to keep water and mud from inundating the workers and equipment in the tunnel. Builders of the Holland Tunnel used a shield that enveloped the work site as the excavation progressed; this also avoided obstruction of shipping traffic during construction.

Spearheaded by Hugh Cooper, the Keokuk Dam & Power Plant served as a prototype for many future power plants. The project harnessed the hydropower of the Mississippi River, between Keokuk, Iowa and Hamilton, Illinois.

The crest of the dam is nearly a mile long. The dam structure features 119 arch spans between six-foot-thick piers and a 110-foot-wide pneumatic lock. Combined with the lock, the dam reduced travel time for steamboats by nearly two hours.

The North Island Main Trunk Railway permitted overland travel and development of the New Zealand hinterland. Built under challenging conditions and over difficult terrain, all cuts, fills, and tunneling were minimized by careful use of the topography and by innovative engineering. 

Over 30 miles south of Taumarunui, the North Island Main Trunk Railway climbs 2,086 feet to the edge of the great Waimarino Plateau. But over the last seven miles, an abrupt increase in altitude of over 700 feet posed an engineering challenge that led to the design of the famed Raurimu Spiral. 

In the mid-1800s Virginia City was America's greatest producer of high-grade silver and gold ore. When mining activities began, natural springs provided water to the camps. As the population grew, the Virginia and Gold Hill Water Company was formed to address the need for more water. The company first drew water from tunnels that had been driven into the mountains by prospectors. Water was stored in wooden tanks and sent through pipes into the town.