Editing Ancient Roman architecture (section)

=== Dams ===
{{further|List of Roman dams and reservoirs}}
Roman dam construction began in earnest in the [[History of the Roman Empire|early imperial period]].{{sfn|Hodge|1992|p=87}} For the most part, it concentrated on the semi-arid fringe of the empire, namely the provinces of [[Roman North Africa|North Africa]], the [[Near East]], and [[Hispania]].{{sfn|Schnitter|1978|p=28, fig. 7}}{{sfn|Hodge|1992|p=80}}{{sfn|Hodge|2000|p=332}} The relative abundance of Spanish dams below is due partly to more intensive field work there; for [[Roman Italy|Italy]] only the [[Subiaco Dams]], created by emperor [[Nero]] (54–68 AD) for recreational purposes, are attested.{{sfn|Smith|1970|pp=60f.}}{{sfn|Hodge|1992|p=87}} These dams are noteworthy, though, for their extraordinary height, which remained unsurpassed anywhere in the world until the [[Late Middle Ages]].{{sfn|Hodge|1992|p= 87}}

The most frequent dam types were earth- or rock-filled [[embankment dam]]s and masonry [[gravity dam]]s.{{sfn|Hodge|2000|pp=331f.}} These served a wide array of purposes, such as [[irrigation]], [[flood control]], river diversion, soil-retention, or a combination of these functions.{{sfn|Hodge|1992|pp=86f.}} The impermeability of Roman dams was increased by the introduction of waterproof hydraulic [[mortar (masonry)|mortar]] and especially ''[[opus caementicium]]'' in the [[Concrete Revolution]]. These materials also allowed for bigger structures to be built,{{sfn|Smith|1971|p=49}} like the [[Lake Homs Dam]], possibly the largest water barrier today,{{sfn|Smith|1971|p=42}} and the sturdy [[Harbaqa Dam]], both of which consist of a concrete core.

Roman builders were the first to realize the stabilizing effect of [[arch]]es and [[buttress]]es, which they integrated into their dam designs. Previously unknown dam types introduced by the Romans include [[arch-gravity dam]]s,{{sfn|Hodge|2000|p=332}}{{sfn|James|Chanson|2002}} [[arch dam]]s,{{sfn|Smith|1971|pp=33–35}}{{sfn|Schnitter|1978|pp=31f.}}{{sfn|Schnitter|1987a|p=12}}{{sfn|Schnitter|1987c|p=80}}{{sfn|Hodge|2000|p=332, fn. 2}} [[buttress dam]]s,{{sfn|Schnitter|1987b|pp=59–62}} and [[Arch dam#Variations|multiple-arch buttress dams]].{{sfn|Schnitter|1978|p=29}}{{sfn|Schnitter|1987b|pp=60, table 1, 62}}{{sfn|James|Chanson|2002}}{{sfn|Arenillas|Castillo|2003}}