Zoning, building permits and septic rules in Mill Valley, California

Mill Valley’s own rules

• Local zoningPresent (with conditions)

  Land inside Mill Valley city limits. The city's own Title 20 zoning code governs use and development there; this claim does not apply to the unincorporated county.

  • Existence of the zoning title is confirmed from the eCode360 table of contents only. The district tables, use lists and procedures in Title 20 were not opened and are not recorded here.

  “title 20 zoning (§ 20.04.010 – § 20.100.160)”

• Well permitRequired

  Drilling, constructing, remodeling, reconstructing, destroying or abandoning any groundwater well or test well inside Mill Valley city limits

  • Application to the Director of Planning and Building on a city form, with a fee set by council resolution (§ 14.06.010).
  • Potable wells on a single-family lot are allowed only if all of these apply (§ 14.06.020): no part of the lot is within 125 feet of a public water main; the fire department certifies adequate public water for fire protection; the city engineer certifies access for drilling and water hauling; a yield test shows at least 1 gallon per minute over an 8-hour pumping test, run June 1 to November 15 by a licensed contractor; a storage tank of at least 1,000 gallons is provided; the health officer's standards are met; and a hold-harmless agreement is executed and recorded with the Marin County Recorder.
  • Irrigation and nonpotable well permits go through the public water provider review (§ 14.06.030).

  minimum sustained yield: >= 1 gallons per minute (8-hour sustained pumping test, June 1 to November 15) · minimum storage tank capacity: >= 1000 gallons

  “no person shall drill, construct, remodel, reconstruct, destroy or abandon any groundwater well or test well without first submitting an application to and receiving a permit from the director of planning and building of the city of mill valley.”

• Subdividing landRegulated (with conditions)

  Land divisions inside Mill Valley city limits, including urban lot splits

  • Title 21 (Plats and Subdivisions) is listed in the code table of contents. The urban lot split chapter says such applications are handled ministerially, with a decision within 60 days of a complete application. The Title 21 subdivision standards and tentative map steps were not opened.

  “an application for an urban lot split pursuant to this chapter shall be considered ministerially by the planning director or designee, as noted in subsection b below.”

• Permit feesVariable (with conditions)

  Well permits inside Mill Valley city limits

  • The fee amount is not on the code page; it is set by city council resolution, and the schedule was not located. General building and septic fees are not covered by this claim.

  “prior to issuance of a well permit, a fee shall be collected based on the fee schedules set by resolution of the city council for plumbing and electrical code applications.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Mill Valley or Marin County directly.

• Building permit — New home construction inside Mill Valley city limits
• Owner-builder exemption — Owner-builder permit exemption inside Mill Valley city limits
• Inspections — Building inspections inside Mill Valley city limits
• Certificate of occupancy — Certificate of occupancy for new homes inside Mill Valley city limits
• Zoning districts — Zoning district map and district list for Mill Valley city

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Off-grid gear

Going off-grid in Mill Valley means bringing your own water and power. The kit we’d start with:

• Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
• Power Bluetti Solar generators and home battery backup for living off the grid.
• Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
• Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.

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