1.   Like an army, sandbagging volunteers retreated, erecting dikes farther inland.

2.   They erected earthen dikes to form vast ponds for the oil, putting up new barriers further away each time the advancing crude overran its banks.

3.   Its dike had been erected hastily over the past few weeks.

4.   The temporary dike was erected to hold back floodwaters that could make an end run into the city.