Assertion: reservoir | /r/MadeOf | excavation
Facets:
value: usually
type: DEGREE
value: by building a complete encircling bund
type: MANNER
value: partly
type: DEGREE
Source sentences:
text: Such reservoirs are usually formed partly by excavation and partly by building a complete encircling bund or embankment, which may exceed 6 km (4 miles) in circumference.