33.1 R: STREAMS AND RIPARIAN CORRIDORS PROTECTION

33.1.1 Purpose. The purpose of these regulations is to provide for the maintenance, enhancement, and, where feasible, restoration of water resources by restricting development, and by minimizing adverse effects of runoff, interference with surface waterflow, and alteration of natural streams, and by protecting riparian habitats. (Former Section CZ#A314-63(A))

33.1.2.1 All streams, riparian corridors and riparian forests designated “R” on the Zoning Maps; (Former Section CZ#A314-63(B)(1))

33.1.2.2 All perennial and intermittent streams as delineated on U.S. Geological Survey 7.5-minute quadrangles. (Former Section CZ#A314-63(B)(2))

33.1.2.3 All riparian lands and coastal streams listed in the Coastal Land Use Plan. (Former Section CZ#A314-63(B)(3))

It should be noted that additional stream protection regulations in Chapter 2 apply specifically to the Coastal Zone segments of the Mad and Eel Rivers.

The Humboldt County Code is current through Ordinance 2784, passed March 10, 2026.

Page 172 of 1183

Title III Land Use and Development | Humboldt County Code

These

regulations shall be in addition to regulations imposed by the primary zone, development regulations, and other coastal resource special area regulations. Wherever the provisions of these regulations conflict with or are inconsistent in application with any other regulation, the regulation which is most protective of natural resources shall apply. (Former Section CZ#A314-63(C))

33.1.4 Consultation with Department of Fish and Game. The County shall request the California Department of Fish and Game to review development plans proposed within stream channels and riparian corridors. The Agency shall be requested to respond within ten (10) working days of the referral. (Former Section CZ#A314-63(D))

33.1.5 Permitted Development within Coastal Stream Channels. New development within stream channels located within the County’s Coastal Zone, shall be limited to the following uses: (Former Section CZ#A314-63(E))

33.1.5.1 Wetlands, fishery, and wildlife enhancement and restoration projects and small hydroelectric generating facilities; (Former Section CZ#A314-63(E)(1))

33.1.5.2 Pipelines, utility lines, municipal water systems, wells in rural areas, and incidental public service purposes; (Former Section CZ#A314-63(E)(2))

33.1.5.3 Road crossings, consistent with all of the applicable “Findings” provisions of Chapter 2. (See, Section 312-17, which sets forth findings required for all permits, and Section 312-39.11, which sets forth the Resource Protection Findings relating to Coastal Road Construction.) (Former Section CZ#A314-63(E)(3))

33.1.5.4 Maintenance dredging for flood control and drainage purposes, consistent with the Transitional Agricultural Land Use regulations. (Former Section CZ#A314-63(E)(4))

33.1.5.5 Maintenance of levees, roads, dikes, drainage channels, floodgates and tidegates including replacement; (Former Section CZ#A314-63(E)(5))

33.1.5.6 Construction of new fences, so long as it would not impede the natural drainage; (Former Section CZ#A314-63(E)(6))

33.1.5.7 Bank protection, surface mining, and other development consistent with the provisions of subsection 33.1.7, Permitted Development and Uses Within Riparian Corridors and Forests. (Former Section CZ#A314-63(E)(7))

33.1.6 Definition of Coastal Riparian Corridors and Forests. For purposes of these regulations, riparian corridors on all perennial and intermittent streams located within the County’s Coastal Zone, shall be defined as one (1) of the following: (Former Section CZ#A314-63(F))

33.1.6.1 The larger of:

33.1.6.1.1 A minimum setback of one hundred (100) feet on both sides of the stream, as measured horizontally from the stream transition lines; or (Former Section CZ#A314-63(F)(1)(a))

The Humboldt County Code is current through Ordinance 2784, passed March 10, 2026.

Page 173 of 1183

Title III Land Use and Development | Humboldt County Code

33.1.6.1.2 A minimum setback of fifty (50) feet plus four (4) times the average percent of slope on both sides, as measured horizontally along the slope perpendicular to the stream transition lines; up to a maximum of two hundred (200) feet from the stream transition line on both sides of the streams; or (Former Section CZ#A314-63(F)(1)(b))

33.1.6.1.3 Where significant areas of riparian vegetation, landslides and areas of slope instability exist adjacent to riparian corridors, as defined in accordance with the setbacks required in subsections 33.1.6.1.1 and 33.1.6.1.2, the riparian corridors shall be expanded to include such areas to a maximum setback of two hundred (200) feet from the stream transition lines; or (Former Section CZ#A314-63(F)(1)(c))

33.1.6.1.4 Along the Eel River and within riparian forests mapped in the Eel River Area Plan, two hundred (200) feet measured as the horizontal distance from the stream transition line. (Former Section CZ#A314-63(F)(1)(d))

33.1.6.2 If either the County or the landowner requests, they may agree to expand the width of the riparian corridor to protect significant areas of vegetation or special habitat areas adjacent to the corridor described in paragraph 33.1.6.1. (Former Section CZ#A314-63(F)(2))

33.1.6.3 The width of the riparian corridor, as described in paragraph 33.1.6.1, may be reduced where such a reduction would not result in the removal of the woody vegetation, and the County determines, based on specific factual findings, that a reduction of the corridor width will not result in a significant adverse impact to the habitat, and is consistent with the adopted Local Coastal Plan. (Former Section CZ#A314-63(F)(3))

33.1.7.1 Timber management and timber harvesting activities regulated by the California Department of Forestry and the Board of Forestry, and forest improvement activities carried out under the Forest Improvement Program (FIP), Agricultural Conservation Program (ACP), or California Forest Improvement Program (Cal FIP) shall be exempt from requirements of this section. (Former Section CZ#A314-63(G)(1))

33.1.7.2 New development within riparian corridors shall be limited to: (Former Section CZ#A314-63(G)(2))

33.1.7.2.1 Maintenance dredging for flood control and drainage purposes consistent with the Transitional Agricultural Land Regulations; (Former Section CZ#A314-63(G)(2)(a))

33.1.7.2.2 Maintenance or replacement of flood control structures, roads, fences, drainage channels, levees, floodgates, and tide gates; (Former Section CZ#A314-63(G)(2)(b))

33.1.7.2.3 Wells in rural areas; (Former Section CZ#A314-63(G)(2)(c))

33.1.7.2.4 Replacement or construction of roads, bridges, pipelines, electrical utility lines, municipal water systems, and incidental public service purposes, provided that the length of the facilities within the riparian corridor shall be minimized, where feasible, by rights-of-way which cross streams at right angles and do not parallel streams within the riparian corridor; (Former Section CZ#A314-63(G)(2)(d))

The Humboldt County Code is current through Ordinance 2784, passed March 10, 2026.

Page 174 of 1183

Title III Land Use and Development | Humboldt County Code

33.1.7.2.5 Removal of trees for disease control, or public safety purposes, or for firewood for personal use; (Former Section CZ#A314-63(G)(2)(e))

33.1.7.2.6 New fences, as long as they do not impede natural drainage or would not adversely affect the stream environment or wildlife. (Former Section CZ#A314-63(G)(2)(f))

33.1.7.2.7 Timber management activities, provided that:

33.1.7.2.7.1 In pre-commercial thinning and release activities, at least fifty percent (50%) of the treecrown canopy and fifty percent (50%) of other vegetation present before management operations shall be left standing. If either the County or the landowner requests, they may agree, after an on-the-ground inspection, to increase these percentages to protect special habitat values. (Former Section CZ#A314-63(G)(2)(g)(i))

33.1.7.2.7.2 Follow-up treatments or other timber management activities which affect the tree canopy shall be permitted only when the canopy has been sufficiently re-established to prevent substantial adverse effects on soil erosion, wildlife, aquatic life, or the beneficial uses of water. These activities shall maintain a tree canopy similar to that which existed upon the completion of the initial thinning or release. (Former Section CZ#A314-63(G)(2)(g)(ii))

ivities which affect the tree canopy shall be permitted only when the canopy has been sufficiently re-established to prevent substantial adverse effects on soil erosion, wildlife, aquatic life, or the beneficial uses of water. These activities shall maintain a tree canopy similar to that which existed upon the completion of the initial thinning or release. (Former Section CZ#A314-63(G)(2)(g)(ii))

33.1.7.2.7.3 In all timber management activities, including but not limited to pre-commercial thinning, release activities, and site preparation, heavy equipment shall be excluded from any area within fifty (50) feet, measured as a slope distance, from the stream transition line, and shall not be permitted in other portions of the riparian corridor except where justified as the least environmentally damaging feasible alternative. (Former Section CZ#A314-63(G)(2)(g)(iii))

33.1.7.2.7.4 All activities shall be consistent with the Timber Harvest Rules of the California Board of Forestry which are applicable to the protection of aquatic life and water quality. (Former Section CZ#A314-63(G)(2)(g)(iv))

33.1.7.2.7.5 Timber management proposals in conformance with the requirements listed in subsections 33.1.7.2.7.1 through 33.1.7.2.7.4, shall be prepared by a Registered Professional Forester. (Former Section CZ#A314-63(G)(2)(g)(v))

33.1.7.2.8 Timber harvests of merchantable timber eighteen (18) inches in diameter, measured at four and one-half (4½) feet vertically above the ground, or greater, provided that timber harvest practices shall be consistent with those permitted by the Forest Practices Rules for Stream Protection Zones in Coastal Commission Special Treatment Areas. Unmerchantable hardwoods or shrubs shall be protected from unreasonable damage. Timber harvest proposals shall be prepared by a Registered Professional Forester. (Former Section CZ#A314-63(G)(2)(h))

33.1.7.2.9 Public access trails provided that the length of the trail within the riparian corridor shall be minimized, where feasible, by rights of way which cross streams at right angles, which are kept as far up slope from the stream as possible, which involve a minimum of slope disturbance and vegetative clearing, and are the minimum width necessary. (Ord. 2277, § 1, 8/27/2002)

The Humboldt County Code is current through Ordinance 2784, passed March 10, 2026.

Page 175 of 1183

Title III Land Use and Development | Humboldt County Code

33.1.7.3 Within riparian forests in the Eel River Planning Area: Conversion to agriculture is permitted on soils that are shown to be Class I or Class II, provided that a minimum 200 foot buffer of woody riparian vegetation remains between the boundaries of converted areas and the stream transition line. (Former Section CZ#A314-63(G)(3))

33.1.8.1 Protection measures for the Mad and Eel River banks shall be permitted for the following purposes: (Former Section CZ#A314-63.1(A))

• 33.1.8.1.1 Maintenance of necessary public or private roads; (Former Section CZ#A314-63.1(A)(1))

• 33.1.8.1.2 Maintenance of existing levees and dikes; (Former Section CZ#A314-63.1(A)(2))

33.1.8.1.3 Protection of principal structures in danger due to erosion; and/or (Former Section CZ#A314-63.1(A)(3))

33.1.8.1.4 Protection of lands zoned AE (Agricultural Exclusive) from erosion. (Former Section CZ#A314-63.1(A)(4))

33.1.8.2 Types of Bank Protection Measures Permitted. The bank protection measures permitted are listed below in order of preference. The measures chosen for any bank protection project shall employ the highest-ranked protection measures wherever feasible. The preference ranking for permitted protection measures shall be as follows: (Former Section CZ#A314-63.1(B))

• 33.1.8.2.1 Piling fence; (Former Section CZ#A314-63.1(B)(1))

• 33.1.8.2.2 Rock hard points; (Former Section CZ#A314-63.1(B)(2))

• 33.1.8.2.3 Continuous revetment. (Former Section CZ#A314-63.1(B)(3))

33.1.9 Required Findings. A Coastal Development Permit for development or activity within stream channels and riparian corridors shall be approved only if the applicable Resource Protection and Impact Findings in Chapter 2, Procedures, Supplemental Findings, are made. (Former Section CZ#A314-63(H))

33.1.10 Required Mitigation. The best feasible measures to mitigate adverse environmental effects of

development within riparian corridors shall be provided, and shall, at a minimum, include the following: (Former Section CZ#A314-63(I))

33.1.10.1 Replanting of disturbed areas with riparian vegetation; or posting of a performance bond

guaranteeing re-establishment of natural vegetation within two years (2yr). The mitigation plan for replanting and/or bonding shall be approved by the Hearing Officer. (Former Section CZ#A314-63(I)(1))

33.1.10.2 Retaining snags, unless removal is required by CAL-OSHA regulations or for stream bank protection; (Former Section CZ#A314-63(I)(2))

The Humboldt County Code is current through Ordinance 2784, passed March 10, 2026.

Page 176 of 1183

Title III Land Use and Development | Humboldt County Code

33.1.10.3 Retaining live trees with visible evidence of current use as nesting sites by hawks, owls, eagles, osprey, herons or egrets. (Former Section CZ#A314-63(I)(3))

33.1.11 Required Mitigation for Bank Protection Projects. Bank protection projects employing rock hard points or continuous revetment shall incorporate, at a minimum, the following mitigation measures: (Former Section CZ#A314-63.1(C))

33.1.11.1 Bank protection projects, including design and materials, shall minimize adverse effects on fisheries, wildlife and recreation; (Former Section CZ#A314-63.1(C)(1))

33.1.11.2 Where feasible, riparian vegetation shall be planted and maintained within the riparian corridor up to two hundred (200) feet landward of the bank protection project throughout its length. (Former Section CZ#A314-63.1(C)(2))

313-34 “S” Combining Zone Designations