To dig a utility trench in the right-of-way of San Mateo County's unincorporated districts requires an encroachment permit from the Department of Public Works.
- Behind walkways, paths, sidewalks - $127
- For laterals and other services in the travel way - $380
- For a main line less than or equal to 100 feet - $1900
- For a main line greater than 100 feet - $1900 +0.50/foot of trench