Environmental Rules in Thousand Oaks, CA (2026)
5 verified environmental rules for Thousand Oaks, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
Stormwater Management
Thousand Oaks makes it unlawful to discharge anything but stormwater into the City's storm drain system, and specifically calls out dumping yard trimmings, cut grass, or paint clean-up water down a gutter or drain as prohibited. The rule implements the federal Clean Water Act and the City's NPDES permit, and applies to any property owner or occupant whose land drains into the storm system.
Environmental: Stormwater
Some RestrictionsThousand Oaks Municipal Code (TOMC) § 7-8.201 (Prohibition of Illicit Connections, Improper Property Maintenance, and Illicit Discharges)
(a) The unauthorized discharge of a pollutant into the storm drain system is unlawful and prohibited. All discharges of material other than stormwater must be in compliance with NPDES Permit No. CAS063339 or any other NPDES permit issued by the State of California. ... (b) Unless in full compliance with a discharge permit, it is unlawful to and no person shall: ... (4) Use the City's storm drai...
Erosion Control
Thousand Oaks requires a City-issued grading permit before anyone excavates, fills, or relocates earth on a property, and additional Planning Commission or City Council approval for grading on natural slopes steeper than 25%. Minor work (small excavations or shallow fills under 50 cubic yards) is exempt, but anything larger triggers the full permit and bonding process.
Environmental: Grading Drainage
Some RestrictionsThousand Oaks Municipal Code (TOMC) § 7-3.07 (Permits Required)
No person shall commence or perform any grading or relocation of earth, and no person shall import or export any earth materials to or from any grading site without first having obtained a grading permit. No person shall commence or perform any grading or relocation of earth on land having a natural slope greater than twenty-five (25%) percent without first obtaining approval from the Planning ...
Flood Zones
In any FEMA-designated special flood hazard area of Thousand Oaks, no structure or land can be built, extended, converted, or altered without full compliance with the City's flood-damage-prevention chapter, and violating those requirements is a misdemeanor. The chapter sets elevation, floodproofing, and anchoring standards administered by a Floodplain Administrator (the City Engineer or designee) through a mandatory development permit.
Environmental: Flood Zones
Significant RestrictionsThousand Oaks Municipal Code (TOMC) § 4-7.03(c) (General Provisions — Compliance)
No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the requirements (including violations of conditions and safeguards) shall constitute a misdemeanor. Nothing herein shall prevent the City Council from taking such lawful action as is necessary to prev...
Defensible Space
Thousand Oaks parcels in state and local responsibility fire zones must maintain 100 feet of defensible space around structures, enforced by Ventura County Fire after the 2018 Borderlands fire.
Defensible space PRC 4291 in Thousand Oaks
Some RestrictionsCalifornia Public Resources Code Section 4291 (Defensible space)
(a) A person who owns, leases, controls, operates, or maintains a building or structure in the state responsibility area shall at all times do all of the following: (1) (A) Maintain defensible space of 100 feet from each side and from the front and rear of the structure, but not beyond the property line, except as provided in subparagraph (B). The amount of fuel modification necessary shall con...
Flood Elevation Requirements
In FEMA-mapped special flood hazard areas, Thousand Oaks requires the lowest floor of new construction and substantial improvements, including basements, to sit at or above the base flood elevation (BFE). The City Engineer enforces the standard as Floodplain Administrator under TOMC Chapter 7.
Thousand Oaks Base Flood Elevation Rules
Some RestrictionsThousand Oaks Municipal Code (TOMC) § 4-7.05(a)(4)(i)
(i) Residential construction. All new construction or substantial improvements of residential structures shall have the lowest floor, including basement: (aa) In AE, AH, A1-30 Zones, elevated to or above the base flood elevation. (ab) In an AO zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least tw...
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County ordinances apply to unincorporated areas and may supplement Thousand Oaks city rules.
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