OSM tag name=Nicasio Reservoir matches Nicasio Reservoir in these Wikidata fields:
Reservoirs in California | man_made=reservoir_covered, landuse=reservoir, water=reservoir |
Reservoirs in Marin County, California | man_made=reservoir_covered, landuse=reservoir, water=reservoir |
Reservoirs in Northern California | man_made=reservoir_covered, landuse=reservoir, water=reservoir |