Why are embankment dams often used in broad valleys?

Embankment dams are often preferred for broad, wide valleys because they are well-suited to sites where a very long barrier is required to block the river or stream.1

While masonry or concrete gravity dams are typically used in narrow gorges—where the total volume of material needed is limited—broad valleys necessitate a much larger structure. Embankment dams, which are constructed using earthfill or rockfill, are often more cost-effective and practical for these expansive sites, as the choice of design is heavily influenced by the site's configuration, geology, and the availability of construction materials. Like concrete gravity dams, the weight of an embankment dam functions to deflect the horizontal thrust of water pressure down to the foundation, provided the foundation is stable and deformation is controlled.12