The following was submitted as public comment on the San Anselmo Flood Risk Reduction Project Draft EIR.
Summary Response to Sections:
2.2 Summary of Impacts and Mitigation Measures
2.3 Summary of Significant Unavoidable, Growth-Inducing, and Cumulative Impacts
2.5 Summary of Alternatives to the Project
2.6 Significant Irreversible Environmental Changes
2.7 Areas of Known Controversy
2.8 Major Conclusions and Issues to Be Resolved
2.10 Other Social and Economic Impacts Not Found to Be Significant
3.1.1 Ross Valley Flood Protection and Watershed Program Summary
When the EIR omits aspects of the proposal that weigh against the selected proposal, the document is as flawed as the development process. Where incorrect data and irrelevant assumptions remain embedded in computer programs, models mislead.
When admittedly, this EIR is “tiered’’ because data to support specific elements remains undiscovered, it is impossible for the public to provide either substantive Comment or meaningful support for these proposals.
The proposed project and the alternatives (except Do-Nothing) share the same challenges:
- induced flooding;
- constricting floodplain characteristics, bedrock, sediment and sinuosity;
- use of private properties.
Each of these challenges is substantial with impacts that must be considered significant. If possible mitigations were sought, negative consequences of each mitigation may well exceed public perception of benefits gained.
The haste and manner of County tactics used to keep the development process ‘in-house’ to evade public scrutiny and to limit participation have weakened confidence in the trustworthiness of County representations.
For example, confusion is created when the EIR gives specific instruction to address Comment to Rachel Reid whereas the County Notice advising careful attention to how to submit Comment gives a different process, name, and email. Such discrepancies are counter-productive to public participation and support.
Using the CEQA process to inhibit consideration of fiscal impacts and cost effectiveness is short-sighted and unwise.
Grant-chasing has been costly. $8M is inconsequential when contrasted with the long-term effects of this County enterprise.
Without the utmost transparency in preparation of the FEIR and any decision on certification, I see continuation of the challenges and controversy that have prevented meaningful flood damage reduction for so many years.
It is no accident that this response may read as an indictment.
2.5.2 Morningside/Passive Basin Alternative:
Dismissing this Alternative raises the question of why one area is deemed more worthy of protection than another. The heavily congested area from Morningside, along the evacuation route of Sir Francis Drake Boulevard, and through Drake High School contains multiple constrictions and potential slope failures. Continuing downstream, under existing conditions, flood waters escape overbank from Nokomis Ave and Madrone Ave in the reach between Madrone Ave and Sycamore Ave and from Sycamore Ave and Bridge Street bridges. These areas are among the most naturally flood-prone and most relatively confined reaches in the watershed, located in an upstream reach that carries an estimated ten percent less flow than the steeper reach below the Creek Park bedrock outcrop. For these areas lying upstream of the controlling Creek Park bedrock outcrop, in-channel capacity increases may lead to an increase in downtown flooding from a backwater with resultant increased water surface elevation (WSE). Removing #634-636 San Anselmo Avenue accelerates this cascading effect for which a 26-31.5 AF basin located miles upstream appears an unrealistic mitigation measure. The EIR lists of impacts and mitigations does not include these potential effects and is, therefore, insufficient.
The Passive Nursery basin design’s attributes of less fill, construction and maintenance are important considerations in a County where DPW has demonstrated an inability to accomplish long-term, vital operation and maintenance (O&M) operations.
The absence of a diversion structure resulting in less sediment is important because of County and Fairfax’s limited budget and public works capabilities leading to long-term O&M considerations.
The absence of a diversion structure resulting in less sediment should be weighed more positively because decreased potential flooding to surrounding private properties may increase public support and lessen litigation.
2.5.3 Raised Building Alternative
Task E of the County contract awarded January 30, 2018, provides for the consultant to:
“… consult with Town of San Anselmo officials, geotechnical and structural engineers and architects and commercial real estate developers re. The general feasibility of removing BB2 and constructing a full or partial footprint replacement version BB2 that is entirely above the existing and/or future FEMA BFE and in a manner likely to be permitted by the regulatory agencies as a self-mitigating or off-site replacement facility…”
The DEIR mentions preservation of #634-636 San Anselmo Avenue (a.k.a. BB2) but contains no mention of a full or partial replacement FEMA compliant structure, focusing instead on the difficulties of raising the existing building. The EIR presentation restricting this Alternative to preservation of the existing structure and omitting any replacement building considerations is incomplete.
2.5.4 Increased Capacity Basin Alternative:
The EIR discussion of increased risks and impacts associated with the increased capacity suggest awareness of the severity of problems attending selection of this Alternative which is not the “Environmentally Superior Alternative”. To the EIR text I would add: the Increased Capacity Nursery basin assumes a complex communications, wiring, and power supply infrastructure upon which the successful operation of the flow gates, diversion and overflow structures, and Fairfax Creek flow conditions depend for protection of surrounding private properties and roads. Assuming any communication or operation from a distant Flood Control District is unrealistically optimistic in light of the County’s history of computer ineptitude, and SCADA failures.
3.5.3 Project Operation and Maintenance:
18.104.22.168 Nursery Basin: With any FDS basin, redundancies and physical access for manual backup must be maintained to ensure safe performance. The proposed flap gate and 24-inch storm drain must be inspected and maintained to assure proper function. The statement that anticipated sediment deposition requires one week of a bulldozer and excavator to remove 1600 cu yd. suggests an assumption of emergency maintenance may be unrealistic, especially if the sediment to be removed tops 2100 cu yd. The EIR contains inadequate assessment of impact and remediation for potential emergency response.
The FDS basin’s 36-inch riser pipe used to “minimize” debris-clogging dysfunction depends on access and maintenance that may be impossible in emergency conditions. The potential for blockage and failure remains. An added concern, planned Oaks and Bay trees are notable leaf debris producers. Introducing them to a closed system dependent conduits and gates to drain may be unrealistic.
The Nursery Basin is in a somewhat remote, not readily apparent area where vegetative screening and proposed elevation changes may further limit visibility resulting in delays of corrective O&M measures. A more rigorous inspection process than that outlined in the EIR would assure better function and greater safety.
Failure to fully assess all effects potentially jeopardizing basin function increases risks from the project, these could be hazardous to the general public, private landowners and traffic on SFD Boulevard. Who is accountable? Does the County bear full responsibility for losses arising from all aspects of O&M failure?
22.214.171.124 Downtown San Anselmo Portion
This is so vague, it is laughable. The EIR is peppered with references to increases in flooding that are a consequence of project proposals. The upstream reaches are among the highest sediment producers in North America, yet no attention is given to the subjects of sediment removal, damages from sediment transported in increased flows created by in-channel capacity increases, intensified scour and consequent bank collapses, new vegetation demands, potential need for pumps (supply, installation, O&M, and eventual replacement). This is a serious deficiency in the DEIR. If the project creates such environmental impacts, these must be addressed.
If the intent is to arrive at a publicly supported Project, better to be both accountable and transparent.
Impacts and Mitigation Measures:
4.3-1.1, 4.3-1.3 Twice daily watering of exposed surfaces and use of wet-vac sweepers over 4-8 month period of 12-hour days in downtown and 9-hour days at the Nursery Basin site requires substantial water use. In the year construction is to take place, drought conditions may be exacerbated. Use of site water from dewatering processes may lessen water use, but could lead to increased creek turbidity. These are substantive impacts. No mitigation is provided.
4.3-1.6 Allowing maximum idling time of five minutes for exhaust emissions from an unknown number of the 28- different types of vehicles proposed for 12-hour construction days for 4 months is a major air quality impact on downtown San Anselmo. No mitigation is provided.
4.5-4 Disturbance will be so substantial that abandonment of the area is likely for the numerous birds inhabiting the downtown and Nursery sites. Not removing trees with nests during Feb 1-Aug 31, does little to ensure the non-nesting birds will return after months of construction.
4.5-6 Bats, especially special-status species, enjoying the insect-rich areas above the creeks’ surfaces certainly will be disturbed whether or not their deeply-secreted roosts are found. Eviction is an inhumane mitigation, but with no L’Appart and construction disruption, people may avoid gathering downtown and not need these useful mosquito catchers.
4.5-7b. Habitat Restoration and Monitoring. The revegetated area in downtown is highly visible and an essential part of bank stabilization. The Nursery site must be stabilized to prevent damage to Fairfax creek’s water quality or to the mechanisms by which the basin functions. What is planted and tended by whom and at what cost needs clear definition. Local riparian plant material may not be appropriately decorative for enhancement of the proposed downtown site, yet may be required, by the permitting entity in charge of annual monitoring for five years.
4.7-1.5, 4.7-3 County Liquefaction Susceptibility Hazard maps place the Nursery Basin site in a HIGH Level of Liquefaction Susceptibility. Therefore, claiming excavation and construction from the project would encounter no adverse effects related to landslides, lateral spreading or other slope instability appears unsupportable and mitigation is required.
4.8-3 The potential of the Nursery Basin to impair or interfere with emergency response and emergency evacuation by impacting SFD Boulevard needs more study. Safe operation of the basin depends on physical access for operations and maintenance, reliable communications, consistent power source, control wiring and other support resources. Emergency conditions may result in infrastructure and access losses which cause failure of the flow gates to operate, failure in the flow diversion and overflow structures with attendant risk to the access ramp to SFD Boulevard. First responders traveling from Woodacre to the lower Ross Valley may be affected as well as public use of SFD as an emergency and evacuation route. Clear traffic flow on this roadway must be safeguarded. The EIR fails to include consideration of such essential measures.
Section 4.9, Hydrology and Hydraulic modeling Considerations
I was gratified to read acceptance of the reality that gauge readings from the 1982 storms were largely unknown due to the gauges being overwhelmed. Subsequent high water marks and readings are the basis for estimating the discharge of 1982 and therefore, the discharge remains an estimate. Adoption of the 7200 cfs discharge definition is due to consensus, not proven fact.
I would be gratified to read acknowledgement that the 100 year storm also is an estimate and subject to change and redefinition: an admission that the 2005 storm has been adopted by consensus. The 100 year storm is not a factual reality, but a term of convenience that does not define the true nature of any storm system.
This is a matter of critical importance since flood events from 1982 to the present are more severe during serial rain events. The dissipation rate and amount of soil saturation are important contributing factors, but it is the repeat downpours that have caused Ross Valley’s worst floods. Whether storms will be serial or allow recovery between events is impossible to predict with certainty. Therefore, the assumptions used in defining design storm and project response are estimates.
Similarly, bed load and its attendant sediment deposition, transport and aggradation are based on estimates: estimates upon which friction and resulting turbulence are assumed. Using the wrong Manning’s n value causes unreliable, misleading results that are subject to change. For many years, wrongful Manning’s n and subsequent reformulation and recalculation has been plagued the Corps’ assessment of Corte Madera Creek projects. The Corps projects now have morphed into the Ross Valley watershed wide Program. When I see a Mannings causing unexpectedly low sediment assumptions, I suspect the resulting models are inaccurate due to calculations with an erroneous coefficient of roughness.
It is all very well to cite lessened aggradation as a sign the watershed is stabilizing, but several important considerations are omitted when such assumptions are made: unknown tributaries and old creek beds unexpectedly spring to life carrying new and unanticipated bed loads into the creeks and channel. I experienced this in 1982 and 1986: flooding on my property in 1986 was far more severe than in 1982 because of the resurgence of a formerly quiescent and unidentified creek.
Our creeks are defined by resistant bedrock bases and ever-constricted sides; they swerve and curve according to manmade courses; old water courses reactivate. These things will not change. The creeks are unlikely to widen and the sediment is unlikely to meaningfully decrease.
The EIR is most seriously and distressingly flawed by seeming awareness yet inability to apply relevant knowledge. To hope for broader, more stable creeks is optimistic. To build entire projects on such beliefs is dangerous. I am strongly of the opinion that erroneous data is embedded in models upon which the County is relying and grossly misleading the public. I believe this will be revealed in coming flood events when we will see the sad saga of Units 2, 3, and 4 repeated and exacerbated by the SAFRR.
Maximizing in-channel capacity carries the inherent danger of higher water surface elevations (WSE) with faster, deeper flood flows that overtop creeks creating more, not less, overland flows. Failure to consider increased WSE as a cumulative impact is a defect of the EIR.
Citing planned bridge replacements as mitigation measures for the SAFRR is wrongful and misleading. For example, presumption of a replacement Winship Bridge is not based on reality. Further, Winship bridge backwaters will continue regardless of bridge replacement. Should Winship WSE be exacerbated by the SAFRR, construction, possibly of a temporary nature may be necessary. This may be followed by removal of the temporary construction, followed by even more construction. And the downstream backwater-controlling factors will remain in place. Therefore, the neighborhood will have suffered the rigors of new constructions for naught. This experience, including the noise and vibration of drilling steel casements into bedrock, is one they may long remember.
Correction of the Winship backwater might be possible: were the County to seek new grants to remove the controlling downstream bedrock, tear out the Sir Francis Drake Bridge and realign the creek channel into Ross. I would not count on public support for such proposals.
That the SAFRR creates flooding on properties that do not currently flood is a fatal flaw the EIR openly admits. That private property owners cannot be coerced into accepting County-proposed flood remedies also is made clear. What is unclear is what happens should the County proceed, and induced flooding result? I doubt many taxpayers will approve using flood fees to fight this in the courts, nor would most support the taking of those private properties. That County staff has made certain representations to these private owners, and the exact nature of these representations will receive full public scrutiny through discovery process. Also relevant may be the January 30, 2018, County contract that specifies as Task 10 that the consultant: ” will work with Town of Ross and Town of San Anselmo to prepare and submit a letter to FEMA requesting a waiver to CFR or other requirements considering the unavoidable minor flood water surface elevation rise in the regulatory floodway resulting in increasing flood protection for the broad floodplain areas and emergency service operations and facilities, etc “. It seems quite clear the County was aware induced flooding was a consequence of SAFRR months ago.
The SAFRR might have merit as the culmination of a series of projects extending from the Bay upstream to San Anselmo. However, as a first, and potentially a stand-alone project, it is folly.
Certification of this EIR requires spending unknown millions of dollars of our flood fees in order to capture an $8M state grant. The process more nearly resembles Marin County politics in action than a quest for substantive protection from flooding.
Footnote: This document should be in the Town records as part of the flood control file since it is the current authorization for the construction costs related to the Ross Valley Corte Madera Creek USACE project. As you will note, the cost is allocated 98.5% to Corps and 1.5% to local cash.