[Federal Register Volume 73, Number 130 (Monday, July 7, 2008)]
[Notices]
[Pages 38422-38424]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-15329]


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DEPARTMENT OF DEFENSE

Department of the Army; Corps of Engineers


Intent To Prepare a Joint Environmental Impact Statement/
Environmental Impact Report for the Corte Madera Creek Flood Control 
Project, Marin County, CA

AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD.

ACTION: Notice of intent.

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SUMMARY: The U.S. Army Corps of Engineers (Corps) authorized through 
the Flood Control Act of 1962, Public Law No. 87-4, 87th Congress, 2nd 
Session, approved October 23, 1962, and amended by Section 204 of Pub. 
L. No. 89-789, the Flood Control Act of 1966, and the Water Resources

[[Page 38423]]

Development Act of 1986, will address channel modification 
opportunities to Unit 4 of Corte Madera Creek, Marin County, CA. The 
purpose of the Corte Madera Creek Flood Control Project is to provide 
flood risk management for Corte Madera Creek, from the upstream end of 
the existing Unit 3 concrete channel to Sir Francis Drake Boulevard at 
the border of Ross and San Anselmo. Although Units 1, 2, and 3 channel 
modifications were completed in 1971, public concerns led to a delay in 
the planned actions for Unit 4. In 1996, Marin County requested the 
completion of Unit 4 by the Corps, and damages incurred by the December 
2005 flood have also renewed public interest in finding solutions to 
minimize the risk of future floods. Since 1971, additional technical 
studies were conducted that provide another opportunity to formulate 
and review new alternatives in order to complete the project. This is a 
notice of intent to prepare a joint Environmental Impact Statement/
Environmental Impact Report (EIS/EIR) to consider all reasonable 
alternatives and to evaluate potential impacts associated with the 
proposed actions. The U.S. Army Corps of Engineers is the lead agency 
for this project under the National Environmental Policy Act (NEPA) and 
Marin County Flood Control and Water Conservation District Zone 9 is 
the lead agency under the California Environmental Quality Act (CEQA).

DATES: A public scoping meeting will be held on July 23, 2008, from 7 
p.m. to 9 p.m. Written comments from all interested parties must be 
received by August 6, 2008.

ADDRESSES: The scoping meeting will be held at the Drakes Landing 
Community Room, 300 Drakes Landing, Greenbrae, CA 94904.

FOR FURTHER INFORMATION CONTACT: Questions and comments regarding the 
proposed action and NEPA aspects of the study can be addressed to Ms. 
Nancy Ferris at (415) 503-6865, U.S. Army Corps of Engineers, San 
Francisco District, 1455 Market Street, San Francisco, CA 94103. For 
questions concerning the CEQA aspects of the study, contact Jack Curley 
at (415) 499-3051, County of Marin, P.O. Box 4186, San Rafael, CA 
94913. All written comments can also be faxed to (415) 503-6692 or sent 
electronically to [email protected]. Further information is also 
available on the project Web site at http://www.spn.usace.army.mil/cortemaderacreek/index.html.

SUPPLEMENTARY INFORMATION: The following section will address the study 
area, recent development of technical studies, and some of the 
alternatives that will be addressed in this study.
    1. Background. Corte Madera Creek drains an area of approximately 
28 square miles in Marin County, CA, and discharges into the San 
Francisco Bay just nine miles north of the Golden Gate Bridge. Units 1, 
2, and 3 extend from San Francisco Bay through the communities of Corte 
Madera, Larkspur, Kentfield, and Ross. Unit 4 extends from the 
Lagunitas Road Bridge, near the upstream terminus of Unit 3, to the Sir 
Francis Drake Boulevard Bridge right before the Ross/San Anselmo town 
line. The project was originally authorized in 1962 and construction 
for Units 1, 2, and 3 were completed by 1971. Unit 4 of the original 
project was not started due to a series of design changes, transfer of 
district ownership, property litigation, and lack of public support. 
Unit 3 was built so that it could be modified with the future design 
plans of Unit 4, such that changes to the Unit 3 channel would also be 
evaluated if implementation of project construction in Unit 4 caused 
flooding downstream.
    The Corps has conducted additional studies focused on evaluating 
the design performance of Units 3 and 4 since 1971. These studies have 
identified the unsmooth transition between Units 3 and 4 created by the 
existing Denil fish ladder, the narrow channel condition on the east 
and west bank, and the Lagunitas Road Bridge as constrictions to flood 
flow. The replacement of Lagunitas Road Bridge is an option that is 
being evaluated by the Town of Ross and is not currently part of this 
federal project.
    The following proposed action seeks to address the issues 
associated with the current channel capacity of Unit 4.
    2. Proposed Action. The U.S. Army Corps of Engineers and the Marin 
County Flood Control and Water Conservation District propose to manage 
flood risk along Corte Madera Creek, downstream of Sir Francis Drake 
Boulevard. The proposed action may include changes to the existing 
design of Unit 3 to ensure a total project design capacity. The 
alternatives evaluated will be developed in consideration of fish 
passage for threatened and endangered fish species that migrate through 
the project area.
    3. Project Alternatives. The following represent a minimum of the 
alternatives that will be evaluated in the EIS/EIR regarding the 
proposed project to increase flood flow capacity, in addition to 
considering the improvement of fish passage and bank stability in Corte 
Madera Creek. The possibility of hybrid alternatives representing a 
combination of measures will also be evaluated:
    a. No action. Under this alternative, the current conditions would 
be retained at Units 3 and 4, and flood capacity would remain unchanged 
at approximately 3,200 cfs (cubic feet per second). Under these 
existing conditions, excess flood flows would pass outside the channel 
onto a residential floodplain. The no action alternative would be 
considered as a baseline in evaluating other alternatives.
    b. Minimum action. This alternative addresses the existing Denil 
fish ladder which exacerbates flooding in the Unit 4 channel and is 
inadequate for fish passage. The existing ladder would be replaced with 
a concrete pool-and-chute fish ladder, with a proposed location within 
the upstream length of the Unit 3 concrete channel. Other design 
considerations include meeting current fish passage criteria as 
established by NOAA's National Marine Fisheries Services (NMFS) 
restrictions on the height of vertical leaps. The estimated flood flow 
capacity of Unit 4 would depend on the design of the replacement fish 
ladder.
    c. Unit 4 structural design alternative. In addition to the minimum 
action, flood risk management measures proposed for Unit 4 include (1) 
Installing vertical wall configurations that would widen the channel 
and increase the maximum flood flow capacity to approximately 5,100-
5,400 cfs, depending on the specific design; (2) constructing a bypass 
culvert adjacent to Lagunitas Bridge that would convey high flows from 
the bridge to the beginning of the concrete channel, with capacity 
ranging from 300-1,300 cfs depending on the type of culvert structure; 
(3) installing temporary or permanent low floodwalls or landscape 
berms; (4) enlarging the sediment basin immediately downstream of 
Lagunitas Bridge, which would decrease the water surface profile 
downstream and increase flood flow capacity; (5) creating a natural 
channel bottom with natural grade protection that would accommodate a 
flow rate of approximately 5,400 cfs; and (6) implementing grade 
control in order to stabilize the stream bottom.
    d. Unit 3-4 structural design alternative. Measures that are 
proposed to modify the junction between Unit 3 and 4 include (1) 
Replacing the existing fish ladder with a natural grade roughened rock 
channel between the Unit 3 and 4 transition, which would allow for fish 
passage while increasing flood flow capacity to 4,900 cfs and improving 
conveyance into the existing concrete channel; (2) bank regrading

[[Page 38424]]

and use of biotechnical bank stabilization techniques involving such 
natural materials as native vegetation, logs, and woody debris; and (3) 
installing concrete wing walls to facilitate flood flows into the 
stream channel.
    e. Non-structural alternative. The non-structural plan would 
include expanding the existing floodplain by moving residential 
property through real estate acquisitions.
    4. Environmental Considerations. In all cases, pursuant to NEPA and 
CEQA guidelines, environmental considerations will include human 
health, riparian habitat, improving fish passage and fish habitat, 
geophysical impacts, air quality, hazards, noise, utilities and service 
systems, transportation, land use and planning, historic and cultural 
resources, aesthetics, recreation, social and economic effects, as well 
as other potential environmental issues of concern.
    5. Scoping Process. The Corps and the Marin County Flood Control 
and Water Conservation District is seeking participation of all 
interested federal, state, and local agencies, Native American groups, 
and other interested private organizations or individuals through this 
public notice. The public scoping meeting will be held in Greenbrae, CA 
(see DATES). Any changes to the date, time, or location will be 
published in the local newspaper or provided by mail to those 
requesting information. The purpose of this meeting is to solicit 
comments and questions regarding the potential impacts, environmental 
issues, and the alternatives that should be discussed in the EIS/EIR. 
Public participation will help define the scope of the environmental 
analysis, identify other significant issues, provide other relevant 
information, and recommend mitigation measures, where possible. The 
public comment period closes on August 6, 2008.
    6. Availability of EIS. The public will have an additional 
opportunity to comment on the proposed alternatives after the draft 
EIS/EIR is released.

Craig W. Kiley,
Lieutenant Colonel, U.S. Army, Commanding.
 [FR Doc. E8-15329 Filed 7-3-08; 8:45 am]
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