Arroyo de en Medio (Spanish for "in the middle creek") is a coastal
stream in western
San Mateo County, California. Arroyo de en Medio rises on the western slopes of
Montara Mountain and discharges to the
Pacific Ocean at
Half Moon Bay at the location of the unincorporated community of
Miramar at
Miramar Beach. The watershed of Arroyo de en Medio consists of relatively permeable sandy soils capable of significant recharge to its aquifers, which supply considerable
potable water to the local area.
Arroyo is Spanish for creek;
de en Medio means literally "of in between" but a closer more functional translation may be
in the middle.