Steel dam

[1] Their economics are highly favourable in 21st century due to lower total onsite labour costs, lower cost for bulk material transportation, availability of more construction time in a year, and flexibility in construction plan complying statuary requirements, etc.

[citation needed] Steel dams use a series of footings anchored in the earth.

The girders and plates are angled in the downstream direction so that part of the weight of the water acts with a downward force on the struts and footings, holding them in place.

In both types of construction, it is typical for the plates to have a scalloped appearance, as can be seen in the Redridge Steel Dam illustration, above.

Increasing the girder/plate angle towards the horizontal, the normal component of the force will increase towards vertical; this means that footings do not need to resist as much horizontal force, but requires more steel for a given upstream head.