[Federal Register Volume 69, Number 189 (Thursday, September 30, 2004)]
[Notices]
[Pages 58414-58415]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21994]


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DEPARTMENT OF DEFENSE

Department of the Army; Corps of Engineers


Notice of Intent To Prepare a Draft Environmental Impact 
Statement for the Proposed San Clemente Dam Seismic Hazard Remediation 
Project--Carmel Valley, Monterey County, CA

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

ACTION: Notice of Intent (NOI).

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SUMMARY: The U.S. Army Corps of Engineers (USACE) has received an 
application for Department of the Army authorization from California-
American Water Company (CAW) to deposit approximately 3,200 cubic yards 
of fill material into wetlands and other waters of the U.S. in 
association with remediating the safety hazards of an existing Dam on 
the Carmel River. This application is being processed pursuant to the 
provisions of Section 404 of the Clean Water Act (33 U.S.C. 1344) and 
in accordance with the National Environment Policy Act (NEPA) of 1969 
(42 U.S.C. 4321 et seq.). In accordance with NEPA, USACE has determined 
that the proposed action may have a significant impact on the quality 
of the human environment and, therefore, requires the preparation of an 
Environmental Impact Statement (EIS). A combined Environmental Impact 
Report (EIR)/EIS will be prepared with the USACE as Federal lead agency 
and the California Department of Water Resources, San Joaquin District 
(DWR) as the State lead agency under the California Environment Quality 
Act (CEQA). The basic purpose of the proposed actions is to provide Dam 
safety. The overall project purpose is to have San Clemente Dam meet 
current standards for withstanding a Maximum Credible Earthquake (MCE) 
and the Probable Maximum Flood (PMF) while providing fish passage at 
the Dam; maintaining a point of diversion to support existing water 
supply facilities, water rights and services; and minimizing impacts on 
CAW rate payers.

DATES: A public scoping meeting for this project will be held on 
November 4, 2004, from 6:30 to 8:30 p.m. at the Rancho Canada Golf 
Club, 4860 Carmel Valley Road, Carmel Valley, California. A public 
agency scoping meeting for this project will be held on November 9, 
2004, 10 a.m. to 12 p.m. at the same location. You may mail comments 
to: Phelicia Thompson, U.S. Army Corps of Engineers, Regulatory Branch, 
333 Market Street, 8th Floor, San Francisco, California 94105-2197.

FOR FURTHER INFORMATION CONTACT: Phelicia Thompson, 415-977-8452, or 
electronic mail: [email protected].

SUPPLEMENTARY INFORMATION:
    1. Background: Approximately 2.4 million cubic yards of sediment 
have accumulated behind San Clemente Dam since it was constructed in 
the early 1920s. Engineering studies of San Clemente Dam were conducted 
in the 1990s to evaluate seismic safety at the request of the 
California Department of Water Resources Division of Safety of Dams 
(DSOD). These studies concluded that at the maximum water surface 
elevation of 537 feet (the height of the Dam's crest), the Dam might 
not be stable under the MCE. The Dam could suffer severe structural 
damage leading to the potential loss of the reservoir during a MCE. In 
addition, under the PMF the Dam could overtop and the downstream 
abutment area would be susceptible to excessive erosion, leading to a 
risk of Dam failure. Based on these findings, DSOD has required that 
the San Clemente Dam be brought into safety compliance to withstand 
seismic loading from a MCE on nearby faults and safely pass the PMF.
    2. Description of the Proposed Action: Dam Strengthening. CAW has 
proposed to meet seismic safety needs for the Dam and protect against 
the effects of a PMF by thickening the downstream face of the Dam with 
concrete. A concrete batch plant would be installed on-site to 
manufacture the concrete needed. Sediment accumulated behind the Dam 
would be left in place. However, minor sediment removal may occur to 
ensure proper functioning of the existing water supply intake serving 
the upper Carmel Valley Village area. Water in the reservoir may need 
to be lowered to reduce loading behind the Dam (depending on sediment 
levels). Inflowing streams would be diverted around the work area and 
the plunge pool at the base of the Dam would be dewatered during the 
Dam thickening. This proposed action also includes replacing the 
existing ladder with a new fish ladder compliant with existing

[[Page 58415]]

National Marine Fisheries Service (NMFS) and California Department of 
Fish and Game (CDFG) criteria to provide fish passage. A tower crane 
would be staged at the base of the Dam to move construction materials 
from the batch plant to the Dam face and fish ladder. Access to the Dam 
would be improved by building a new road along the east side of the 
Carmel River, between the Old Carmel River Dam and the base of San 
Clemente Dam. The Dam thickening project would take an estimated four 
years to complete.
    3. Reasonable Alternatives: In accordance with the requirements of 
Section 15124 of the State CEQA Guidelines and 40 CFR 1502.14, 
reasonable alternatives to the proposed action will be evaluated in the 
Draft EIR/EIS as listed below:
    a. Dam Notching Alternative. This alternative would meet the need 
to reduce seismic safety risks by notching the Dam. The action would 
reduce the mass sufficiently to avoid catastrophic failure of the Dam 
during a MCE event. Notching would also be of sufficient size to 
prevent overtopping of the Dam during the PMF. The gates, piers and 
walkway at the top of the Dam would be removed and the Dam would be 
notched to an elevation of about 505 feet in the area of the present 
spillway bays. Sediment in the reservoir would to be removed down to 
the level of the notch. A new intake structure would be constructed to 
allow the Dam to continue serving the upper Carmel Valley Village area. 
A new access road would be constructed to connect Carmel Valley Road to 
the Carmel Valley Filter Plant, to bypass the Sleepy Hollow community 
and to improve safety for large construction equipment. In addition, 
road access from the filter plant to the Dam would be improved. The 
existing primitive road from the Old Carmel River Dam to the base of 
San Clemente Dam would be rebuilt to an elevation above winter flood 
levels. Both the Carmel River and San Clemente Creek would be diverted 
around the reservoir and Dam site and the reservoir would be dewatered 
each year during construction. Accumulated sediment would be removed 
from behind the Dam over two seasons by excavation with heavy equipment 
and transported from the reservoir by truck or via a conveyor belt 
system to a disposal area near the Carmel Valley Filter Plant. The 
existing fish ladder would be rebuilt compliant with existing NMFS and 
CDFG criteria to accommodate the lowered Dam elevation. The Carmel 
River channel in the inundation zone would be restored. The Dam 
notching project would take an estimated six years to complete, 
depending on the effects of annual precipitation upon the construction 
schedule.
    b. Dam Removal Alternative. This alternative would eliminate 
seismic safety and flooding risks through the removal of the Dam and 
the accumulated sediment behind the Dam. A new access road would be 
constructed to connect Carmel Valley Road to the Carmel Valley Filter 
Plant, to bypass the Sleepy Hollow community and to improve safety for 
large construction equipment. In addition, road access from the filter 
plant to the Dam would be improved. The existing primitive road from 
the Old Carmel River Dam to the base of San Clemente Dam would be 
rebuilt to an elevation above winter flood levels. Both the Carmel 
River and San Clemente Creek would be diverted around the reservoir and 
Dam site and the reservoir would be dewatered each year during 
construction. Accumulated sediment would be removed from behind the Dam 
over three seasons by excavation with heavy equipment and transport 
from the reservoir by truck or via a conveyor belt system to a disposal 
area near the Carmel Valley Filter Plant. The existing Dam and fish 
ladder would be demolished and removed from the site. A new intake 
structure would be constructed to allow CAW to continue serving the 
upper Carmel Valley Village area. The river channel would be restored 
through the historic inundation zone. If the Dam and sediment were 
removed in stages, a trap and truck facility would need to be built and 
operated at the Old Carmel River Dam for at least three years. The Dam 
removal project would take an estimated seven years to complete, 
depending on the effects of annual precipitation upon the construction 
schedule.
    c. No Action Alternative. Under this alternative, no changes to the 
existing Dam would be made. The Dam would be left in place with all its 
existing facilities, although the fish ladder would be replaced with a 
new ladder compliant with existing NMFS and CDFG criteria to provide 
fish passage. Most of the sediment would be left in place behind the 
Dam. The reservoir would continue to accumulate sediment at an average 
rate of about 15 acre-feet per year. Minor sediment removal may occur 
to maintain the existing water supply intake serving the upper Carmel 
Valley Village acre. The existing draw down ports in the Dam and the 
existing fish bypass facility would both likely remain operational 
until the reservoir fills with sediment. The existing road between the 
Carmel Valley Filter Plant and the Dam would be improved to provide 
access to the Dam site for fish ladder construction equipment and 
supplies.
    4. Scoping Process: Pursuant to NEPA, the USACE must include a 
scoping process for the Draft EIS/EIR. Scoping preliminarily involves 
determining the scope of the issues to be addresses in the Draft EIR/
EIS and identifying the anticipated significant issues for in-depth 
analysis. The scoping process includes public participation to 
integrate public needs and concerns regarding the proposed action.
    a. Public Involvement Program: Venues for public comment on the 
proposed action will include: Scoping meetings to be held on November 
4, 2004 in Carmel Valley; preparation of a Draft EIR/EIS; and receipt 
of public comment in response to the Draft EIR/EIS.
    b. Significant Issues to be Analyzed in Depth in the Draft EIR/EIS 
include: Impacts to the aquatic environments; impacts to endangered 
species, including but not limited to the California red-legged frog 
and the California Central Coast steelhead; water quality; cultural 
resources; traffic, fish and wildlife resources; public safety, 
including downstream flooding; and other issues identified through the 
public involvement process and interagency coordination.
    c. Environmental Review/Consultation Requirements: NEPA; Section 
404 of the Clean Water Act; Section 401 of the Clean Water Act; 
Endangered Species Act; Magnusun-Stevens Act Provision--Essential Fish 
Habitat; Clean Air Act; National Historic Preservation Act.
    d. Scoping Meeting/Availability of Draft EIR/EIS: The USACE will 
hold a public scoping meeting to provide information on the project and 
receive oral or written comments on the scope of the document. This 
scoping meeting for the project will be held at 6:30 p.m. to Thursday, 
November 4, 2004, at the Rancho Canada Gold Club, 4860 Carmel Valley 
Road, Carmel Valley, California. The Draft EIR/EIS is expected to be 
available for public review in winter of 2006.

    Dated: September 21, 2004.
Calvin C. Fong,
Regulatory Branch Chief.
[FR Doc. 04-21994 Filed 9-29-04; 8:45 am]
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