The Santa María Dam () is a reinforced concrete gravity dam and power plant spanning the Samalá River in Zunil, Escuintla, Guatemala.
The dam's reservoir has a total capacity of 215,500 m3. The water is transported to the powerhouse through 614 m long pressure pipe. The plant has 3 different turbines ( and ) with a total installed capacity of 6.88 MW. The plant has a level declination of 101 m, and a designed flow of 2.35 m3/s for unit 1 and 2, and 2.42 m3/s for unit 3.
The plant started operating in 1927 and produces annually 38 GWh of electrical power.