Trajan. 98-117 AD. AE Sestertius, 32mm. Struck ca 104-107 AD. 

IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS V P P, laureate head right, slight drapery on left shoulder.
S P Q R OPTIMO PRINCIPI, S C across lower field, AQVA 
TRAIANA in exergue, the genius of the Aqua Traiana reclining 
left, elbow resting on urn from which water flows, holding 
reed in right hand; all under an arched grotto. 

RIC II 463; BMCRE 873; Cohen 20.

With kind permission of www.edgarlowen.com, Oct. 2011.