HomeMy WebLinkAbout06 - Dredging in the Navigational Channels of the Lower BayITEM 6
TO: Members of the Newport Beach City Council
FROM: Tony Melum, Division of Harbor Resources
SUBJECT: Dredging in the Navigational Channels of the Lower Bay
RECOMMENDED ACTION:
Approve the attached Resolution supporting federal funding for a dredging project in
Lower Newport Bay and directing that the Resolution and any related correspondence
be directed to the offices of US Representatives Chris Cox (47th Congressional District)
and Dana Rohrabacher (45th Congressional District).
BACKGROUND:
Newport Bay is a combination of two distinct bodies of water, Lower Newport Bay and
Upper Newport Bay. Lower Newport Bay was formerly a coastal lagoon. It is four
miles long and is oriented parallel to the coastline. This lagoon was formed between
1824 and 1862 as a result of sand deposition from the Santa Ana River. Upper Newport
Bay is geologically much older than the Lower Bay and is essentially a submerged river
valley formed by a precursor of the Santa Ana River.
Natural and accelerated erosion within the watershed associated with grading,
agriculture and increased runoff generation has resulted in substantial siltation in the
Upper Bay, which has subsequently been carried down to the Lower Bay by runoff and
tidal action. This influx of siltation has reduced the depth of some of the navigational
channels in the Lower Bay.
Navigational channels were constructed within Lower Newport Bay between 1934 and
1936 as a federal construction project. This dredging included the removal of 8.5
million tons of sand and 550,000 tons of rock. An additional 210,000 tons of rock was
used to extend the west jetty to a length of 2,830 feet and the east jetty to 1,673 feet. A
total of 6.3 million cubic yards of sediment were dredged to deepen the entrance
channel to minus 25 feet and to deepen the main channel to a minus 20 feet, and to form
the turning basin and small channels adjacent to the main channel. This initial
dredging of the bay included a pipeline discharge of the dredge material directly onto
the beaches of Balboa Peninsula.
Since that time, the Army Corps of Engineers (Corps) has dredged the Lower Bay on
only three occasions. In 1941 they deepened the turning basin at the west end of the
Harbor (Lido Village area). In 1981, 82,000 cubic yards of sand were dredged from the
harbor entrance. In 1998, 204,000 cubic meters of sediment was removed from just
below the Pacific Coast Highway bridge at the junction of the Main and Upper Bay
Channels in the area of Harbor and Linda Islands. Except for these three projects,
maintenance dredging by the Corps to maintain the federally authorized harbor
channels has not been necessary.
Federal authority directs the Chief of Engineers of the Corps to maintain the
navigational channels at Newport Bay Harbor when determined advisable in the
interest of providing navigation and safety. As part of their maintenance responsibility
the Corps does annual Newport Bay condition surveys, to ascertain whether the
channels are at or near their design depth and whether additional dredging is
necessary. The survey done in December of 1999 indicated that there was shoaling in
the Lower Newport Bay in approximately five areas (see Attachment B). Those areas
are the main channel adjacent to Via Lido Nord, the turning basin adjacent to the east
end of Lido Island, the channel southeast of Bay Island adjacent to the Peninsula, the
channel adjacent to Harbor Island and Collins Island, and the lower bay channel
between the main channel and South Bay Front on Balboa Island.
That survey indicated the need to remove approximately 408,912 cubic meters of
sediment to return those channels to their original design depth. The approximate cost
of this project would be $4,000,000. The Corps included this $4,000,000 dredging project
in their budget submittal this year.
Unfortunately the Corps recently informed City staff that the Bush Administration has
cut this project from their budget and as a result there will be no dredging done in
Newport Bay this year. It may be possible however, to add this project back into the
Corps budget with the assistance of Congressman Cox and Congressman Rohrbacher
via a congressional "add-on" to the Administration's budget. City staff has worked
with both Representatives' offices outlining the need for Lower Bay Dredging and
suggesting that this congressional add -on process be put in motion. To assist this
process, this Agenda Item asks the City Council to adopt a resolution to be submitted to
both representatives emphasizing the City's desire that this project be included in the
budget.
ATTACHMENTS:
Attachment A - Resolution 2001 -_ relating to Support for Lower Bay Dredging
Attachment B - Map of Lower Bay Dredging Areas
Attachment A
RESOLUTION NO. 2001-
A RESOLUTION OF THE CITY COUNCIL OF
THE CITY OF NEWPORT BEACH REGARDING
THE NEED FOR MAINTENANCE DREDING
IN LOWER NEWPORT BAY
WHEREAS, Lower Newport Bay is the largest recreational small boat harbor within the
state of California and;
WHEREAS, Lower Newport Bay is home port to a United States Coast Guard cutter as
well as the Orange County Sheriffs Harbor Patrol rescue vessels and;
WHEREAS, it is both economically and socially important that Lower Newport Bay be
maintained for both recreational and commercial uses and;
WHEREAS, increased siltation is impacting the safety and navigability of channels in
Lower Newport Bay and;
WHEREAS, federal authority directs the Chief of Engineers of the Army Corps of
Engineers to maintain the navigational channels at Newport Bay when determined advisable in
the interest of providing navigation and safety, now, therefore be it
RESOLVED by the City Council of the City of Newport Beach that the City hereby
urges the prompt federal funding during the Fiscal Year that begins in October 2001 of a US
Army Corps- directed dredging program for Lower Newport Bay and be it also
RESOLVED by the City Council of the City of Newport Beach that this Resolution and
any other related correspondence be forwarded to the offices of the Honorable Chris Cox (47th
District) and the Honorable Dana Rohrabacher (45th District) to urge their support in procuring
the necessary federal funds to do maintenance dredging within the Lower Newport Bay to
insure safe and navigable channels.
ADOPTED this 8w day of May, 2001.
Garold B. Adams
MAYOR
/:llllll_09
LaVonne Harkless
CITY CLERK
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