Oct 2021

Summary of New Stream Rules for Homeowners

We offer this summary of how the new stream rules proposed by Marin County may effect your property and house. We believe the ordinance and exhibits will burden families with costs and delays for ordinary home maintenance and improvements. The rules are confusing and will require homeowners to consult lawyers and pay experts for common projects.

In San Geronimo Valley, 4200 people live in a forest surrounded by dry grassland. The new stream rules discourage sensible vegetation management, and do not require compliance with state law and local fire agencies regarding defensible space and fire prevention.

The SGV Stewards and supporters are not professional developers building new mansions. We are the 2,000 families who live in existing homes, many built decades ago, on small lots close to creeks.

The new stream rules apply to only the San Geronimo Valley. Marin County does not burden any other area with these new costs and delays.


A. Where to read the new stream rules: This is a brief summary. You can read the exact language of the new rules by going to the Marin County website: www.marincounty.org/sca

Scroll down to "2021 SCA Ordinance Documents" Exhibit A is the Stream Conservation Area Ordinance (SCAO). Supporting Resource Materials include: Exhibit C on Site Assessment Exhibit D Standard Management Practices (SMP's)

B. Your comments are welcome: Please send your questions, objections, and recommendations to the public officials we list at the end of this email.

We hope you will participate in the Monday November 8 workshop for the community and the County Planning Commission. Watch your emails for exact time and details how to log onto the virtual meeting. The Planning Commission is scheduled to vote Monday December 13.

C. New Stream Rules: Do you want to: replace your wood deck, repair your roof shingles, or add 400 square feet to your home, or pave your dirt driveway, or build a tool shed, or install solar panels?


"Stream" means a natural flowing open channel with a bed and a bank. Not culverts below ground. Perennial stream flows all year. Intermittent stream is seasonal and may not have surface flow in summer and early fall. SCAO page 14.

"Ephemeral stream" is surface run off during and immediately after rain. An ephemeral is not a stream unless it is a natural watercourse with a bed and a bank. SCAO page 14.


The Stream Conservation Area (SCA) is measured landward from the top of the stream bank. SCAO pages 5-6, section 22.30.045 A.1.a.

SCA is 100 feet on both sides of the stream, if it is perennial or intermittent stream.

SCA is 20 feet on both sides for many ephemeral streams.

SCA may be 100 feet on both sides for some ephemerals, but only if either:
(a) the ephemeral supports riparian vegetation for at least 100 feet in length, or
(b) the ephemeral supports "special status species" such as native grasses.

Try to stay outside the SCA when developing any home project. The Community Development Code defines "development" as including: placement of solid material or structure; grading or removing material; change in density of land use; construction, demolition, or alteration of any structure; or removal of major vegetation.


These sections of the ordinance are the most confusing and difficult to understand.

A. Here are the only allowable land uses for residential properties in the SG Valley (SCAO pages 7-8, section 22.30.045):

(a) Maintaining or repairing existing permitted structures.
(b) Adding up to 500 square feet cumulative to an existing permitted structure, provided the addition does not encroach closer to the creek. The cumulative 500 SF starts on the effective date of the new stream ordinance.
(c) and (g) Projects to improve wildlife habitat or flood control that minimize impacts on wildlife.
(d) Driveway, road or utilities crossings, if no other location is feasible.

B. Other projects may be allowable, but only if: (a) the entire parcel is within the SCA, or (b) development outside the SCA would have greater environmental impacts than development inside the SCA.

C. Blanket Prohibition: "Land uses and improvements not listed above are prohibited . . ." SCAO page 7, section 22.30.045 A.3.

The Blanket Prohibition conflicts with two other sections of the ordinance and should be deleted.

Some activities do not require a land use permit and are permitted in all of Marin County, including the SG Valley (SCAO page 1, section 22.06.050):

C. Interior remodeling that does not expand floor area, or change permitted use, and change exterior appearance. (Can you install inside window shutters and paint the front door, without a land use permit?)
D. Repairs and maintenance of existing improvements that do not change land use and do not expand or enlarge the improvement.

Some projects within the SCA are exempt from stream Site Plan Review (pages 10-11, section 22.52.030). Because these are exempt, they cannot also be "prohibited" under the Blanket Prohibition:
C. Certain small ADU's (Accessory Dwelling Units).
D. 1. Removal of dead or invasive vegetation.
2. Removal or trimming fire-prone trees or vegetation.
3. Planting no-pyrophytic vegetation
4. Voluntary creek restoration with Marin RCD.
Most Important for SG Valley:
5 . Repair, maintenance and replacement of septic systems, consistent with stormwater protections and SMP's.


All development within the SCA in SG Valley will require a "Site Assessment" by a "qualified professional." Even projects that are allowable uses, or do not require a land use permit, or are exempt from Site Plan Review--all will still require a Site Assessment. (Exhibit C, page 1, Preparation of Site Assessment).

The County and Marin RCD will assist homeowners with Site Assessments. The County offers the expertise of the Urban Stream Coordinator (an employee of Marin Resource Conservation District) to prepare a Site Assessment at the County's expense. Alternatively, the property owner may hire a qualified professional at their own expense (Exhibit C page 3).

SGVStewards request this provision be included in the SCA ordinance. The County's offer to pay Marin RCD for Site Assessments is an important incentive for voluntary compliance. It should be adopted by the Board of Supervisors as part of the ordinance. We take little assurance from the statement in Exhibit C of resource materials, where it could be changed by County staff at any time, without adequate notice and hearing.

County staff encourages early consultation with the Urban Stream Coordinator (or another professional), before an application is submitted to Community Development Agency. The Site Assessment will study stream ecology of the area, evaluate possible impacts of the project, recommend mitigation steps, and may recommend or not recommend the project. The Site Assessment can be appealed to the Community Development Agency and/or the Planning Commission (Exhibit C page 4).

Question: How will County staff and Marin RCD meet the requests for Site Assessments?
There are about 2,000 homes in SG Valley, and about 900 houses may be located within the SCA. Families are constantly working on improvements or landscaping projects. Will there be ONE person at RCD assigned to personally visit each home? How long do they expect property owners to wait for their Site Assessment?

The Site Assessment must certify the project will comply with all appropriate SMP's (Standard Management Practices), described in Item 5 below. (SCAO page 8, section 22.30.045 B.)


Every project within the SCA must comply with Standard Management Practices applicable to the project. (SCAO page 8, section 22.30.045 B. and page 12 section 22.52.050.) The SMP's will undoubtedly increase costs and cause delays for families repairing, maintaining or improving their homes.

Exhibit D is 8 pages of detailed SMP's requiring mitigation measures for home projects:
riparian (streamside) vegetation and habitat,
water quality and hydraulic capacity,
pollution prevention for construction,
stormwater management and surface drainage,
public access,
new roads, driveways and stream crossings,
native riparian plants.

What is missing? Fire prevention, defensible space and fire-resilient forestry management.
This is a dangerous omission.
No SMP's require adherence to good fire practices. The website for FireSAFEMarin is merely listed as a "resource".

However there are 16 specific SMP's that prohibit removing native grasses and shrubs, and require re-planting new trees on a 2 to 1 ratio for every tree removed. There is no consideration of the consequences for flammable landscape.

SGVStewards request the SMP's include a section for "Fire Prevention and Preserving Mature Trees"
1. Comply with defensible space and wildfire preparedness of Marin County Fire department, as described in attached checklist.
2. Consult with Marin Wildfire Prevention Authority on ecologically sound practices for wildfire prevention.
3. Manage land and vegetation to support fire resilient forest and to restore forest to old growth conditions.
4. Maintain home landscaping consistent with the yard guidelines of FireSAFEmarin.org, copies attached to the SMP's.


The Director and staff of CDA will evaluate the professional's Site Assessment and Site Plan application from the homeowner. The Director may approve, conditionally approve, or deny the Site Plan Review. (SCAO pages 11 -12, sections 22.52.040 and 22.52.050.)

Some features of the Site Plan may require other permits or compliance with other planning rules, such as septic standards or building permits. The applicant will want to get clear direction from CDA staff about whether the project requires public notice, or opportunity for other parties to object. There may be an appeal or referral to the Planning Commission.

When is Site Plan Review required?

SCAO page 10, section 22.52.020 requires Site Plan Review where development involves:
--increase land coverage over 75% on a single family residential lot;
[even ADU's and house additions less than 500 SF will require Site Plan Review]
--new driveway over 250 feet long;
[paving with asphalt an existing dirt driveway?]
--grading or exposing soil or removing riparian vegetation;
[weed whacking or shrub removal in fire season?]
--increasing lot coverage or surface runoff
[install new gutters or roof shingles?]
--alter the bed or bank or channel of a stream

What projects are exempt from Site Plan Review?
SCAO pages 10-11, section 22.52.030 exempts:
--certain small ADU's;
--removal of dead or invasive vegetation;
--removal or trimming of pyrophytic trees or shrubs;
--planting non-pyrophytic vegetation;
--voluntary creek restoration with Marin RCD;
--repair, maintenance or replacement of existing septic system,
BUT construction of a new septic system is not exempt and requires to Site Plan Review.

No Fees for Site Plan Review

We are informed by CDA staff that, for projects in the SCA of San Geronimo Valley, there will be no application fee for CDA to evaluate your Site Assessment or to perform Site Plan Review. However, the project may involve other permits (such as a building permit) for which regular scheduled fees will be charged.

The County will pay Marin RCD to do the Site Assessment. You may hire your own professional for Site Assessment and pay your own cost.


BOS@marincounty.org Board of Supervisors
DRodoni@marincounty.org Supervisor Dennis Rodoni
RKutter@marincounty.org Rhonda Kutter, Legislative Aide to Supervisor Rodoni
planningcommission@marincounty.org Planning Commission
TLai@marincounty.org Thomas Lai, Director of Marin Community Development Agency
JLiebster@marincounty.org Jack Liebster, CDA staff
KDrumm@marincounty.org Kristin Drumm, CDA staff
MLevenson@marincounty.org Michelle Levenson, CDA staff

SGVStewards encourage all Valley residents to participate in the Monday November 8 community and Planning Commission work shop, which will be held on line.

Visit our website www.SGVSTEWARDS.com for updates, as the county notifies us.