The director of Glendale Water and Power plans to step down from the post this spring, the city announced Tuesday. Ignacio R. Troncoso will retire from the position May 7 after six years with the city. The resignation will take effect in July. Troncoso is credited with implementing environment, safety and security improvements. Previously, Troncoso worked 24 years at the El Paso Electric Co. in Texas. No replacement has been named.