PHONE:
(772) 562-8580 FAX (772) 562-8432
155 August 15, 2003
Brian Trautwein, Environmental Analyst
Re:
Dear Brian:
This letter is in response to your request to the Surfrider Foundation Environmental Issues Team (EIT) for review and comment relative to the referenced Project. This letter is rendered on behalf of the Santa Barbara Chapter and solely reflects my professional opinions as a coastal engineer based on review of documents as referenced below.
The following provides comments relative to your questions (in bold text) as posed in your July 18, 2003 memo request:
Sediment
processes are characterized in the Moffit & Nichols Engineers report titled
“
(1) “cliff erosion” – estimated at “25%”, and
(2) “upcoast river and stream supply”,
The report identifies that “Goleta Slough” historically was a source of sediment via its mouth at the eastern end of the park, but “Debris basins in Goleta Slough and its tributaries now trap significant quantities of sediment in flood years.” The “California Beach Restoration Study” dated January 2002, indicates that within the “Santa Barbara Littoral Cell”, sediment input is over 99% from rivers and less than 1% from bluff erosion.
The 2002
M&NE Report also identifies that
“sediment transport in the region is nearly unidirectional, from west to
east, with occasional short term (a few hours) reversals due to pre-frontal
wind-generated seas during winter storms.” This nearly unidirectional longshore
sediment transport is quite obviously driven by waves from the west. As
identified in the 2002 M&NE Report, waves from the northwest are blocked by
Point Conception and waves from south to southwest are blocked by the
In general, a shoreline segment will accrete if more sediment is moved into the segment than is moved out of the segment; this scenario is associated with a decreasing longshore transport gradient. Comparably, a shoreline segment will erode if less sediment is moved into the segment than is moved out of the segment; this scenario is associated with an increasing longshore transport gradient and a sediment deficit. Shoreline segments of accretion and erosion are common around headland features, which induce a longshore transport gradient.
The Goleta Beach
shoreline is very dependent upon longshore transport of sediment from west to
east around the headland features west of the park including (a) Goleta Point
and (b) the UCSB pump station, revetment and bluff located at the west end of
the park (hereinafter referred to as the “UCSB bluff”). If sufficient
sand is moving along the shoreline at and around the UCSB bluff (transport is
at or near potential),
Historical aerial photographs of the park area for
1929, 1946, 1979, 1991, 1994, and 1998 are provided in Figures 2-3 through 2-5
of the Moffit & Nichols Engineers report titled “Goleta Beach County Park
Long-Term Plan” dated November 2001. These photographs indicate significant
fluctuations in the shoreline at
·
“The
beach accreted after the fill was placed in the late 1940s, becoming very wide
by the end of the 1970s. The UCSB beach became significantly wider between 1943
and 1954, and continued to widen more slowly through the 1960s and1970s.
· Relatively rapid erosion has occurred since the end of the 1970s; the rate of erosion has slowed in recent years.”
This historical characterization indicates that sufficient sand was
transported east around Goleta Point and the UCSB bluff to lead to accretion at
·
“fill
placement in the late 1940s”,
·
forest
fires in 1955 and 1964 which allowed “a significant quantity of sediment to be
transported to the coast”,
·
“1982-1983
El Nińo storms could have brought about significant erosion”
· “debris basins in Goleta Slough and its tributaries have trapped sediment in recent years which would otherwise have reached the coast exacerbating the overall sediment deficit.”
Among these
possible reasons, none are naturally occurring and reliable as means to
provide adequate sediment to
The recent
efforts to construct seawalls at Isla Vista (News Press 1/21/98) and at UCSB
next to Campus Point (News Press
3/28/98), are indications that insufficient sediment exists within the
littoral system to allow for accretion or even maintenance of the shoreline at
b) How do you believe building the 600-foot
revetment in December 2002 impacted these resources and processes?
The revetment prevented erosion of the uplands
landward of the revetment and thus deprived this sediment to the littoral
system. The Moffit & Nichols Engineers report titled “
c) How do you believe these resources and
processes and those down coast, may be affected by leaving the revetment in
place for up to 2 years beyond May 15, 2003?
In the event that the revetment is left in place for two years, the revetment can be expected to (a) deprive the littoral system of about 14,000 cubic yards per year, and (b) result in narrowing of the beach seaward of the revetment at about 20 feet per year. This narrowing occurs as “Passive Erosion” whereas the shoreline migrates landward while the revetment is fixed and does not move.
d) How do you believe these resources and
processes would be affected if the revetment were left in place permanently?
In the event that the revetment is left in place permanently, the revetment can be expected to (a) deprive the littoral system of about 14,000 cubic yards per year, and (b) result in narrowing of the beach seaward of the revetment at about 20 feet per year. This narrowing occurs as “Passive Erosion” whereas the shoreline migrates landward while the revetment is fixed and does not move.
e) What are the cumulative geological
impacts of the 600-foot revetment coupled with other actions undertaken at or
near Goleta Beach, including the 1986 revetments and Parks’ 2200-foot sand berm
authorized through 2005?
The cumulative impacts of the revetments simply characterized as (a) deprivation to the littoral system of the sand retained landward of the revetments, and (b) narrowing of the beach seaward of the revetment at about 20 feet per year for each year the revetments have been in place.
It is my understanding that the County constructed the berm by scraping beach sand from the beach seaward of the revetment and piling the sand in front of and on the revetment. This berm construction may have temporarily resulted in an adjustment of the beach width seaward of the revetment and perhaps even increased the potential for erosion of the piled sand. However, the berm provided no sand to the littoral system and had no significant or measurable effect upon coastal sediment processes.
Please describe how direct, indirect,
onsite and offsite (i.e. down coast), secondary and reasonably foreseeable
impacts would occur.
The revetments would likely affect the downdrift shoreline similar to the UCSB bluff which now appears to trap sand to the west of the bluff and deprives sand to Goleta Beach. As the shoreline around the revetments erode, and the revetments protrude from the shoreline, the revetments can be expected to comparably trap sand on the west side of the revetments and deprive sand from the beaches to the east of the revetments. This “groin effect” would result in increased erosion downdrift of the revetments.
e)
Are any of these impacts significant or potentially significant?
CEQA
Guidelines define "significant effect on the
environment" as "a substantial, or potentially substantial, adverse
change in any of the physical conditions within the area affected by the
project including land, air, water, minerals, flora, fauna, ambient noise, and
objects of historic or aesthetic significance" (Guidelines Section
15382). The revetments are expected to
result in loss of beach area seaward of the revetments on the order of one acre
each year that the revetments remain in place. In addition, potential cumulative downdrift
impacts are expected to affect in excess of one acre of beach and uplands to
the east of the revetments. These impacts are potentially significant.
No, it appears that the revetments do not minimize alteration of the natural terrain. It might be feasible to relocate some park improvements further landward to avoid and minimize impacts to the natural beach. Although the revetments appear to be predominantly sited adjacent to the edge of the parking area at the park and might not be sited further landward to minimize their impacts, relocation of upland improvements or even a seawall with beach nourishment would be expected to have a lesser footprint and impact upon the beach and thus minimize the alteration of the beach.
Yes, as described above, with the expected continued erosion of the beach, the revetments will (a) deprive the littoral system of sand from landward of the revetments, and potentially function as groins to the detriment of the adjacent and downdrift beaches, and (b) through Passive Erosion directly result in narrowing of the beach seaward of the revetment at about 20 feet per year.
No, the revetments, in themselves, do not mitigate
their “adverse impacts on local shoreline sand supply”. Such mitigation can
only be addressed through input of sand into the local littoral system.
No, the revetments do not provide for safe public
access to and along the beach. It is my
understanding that no access stairs or “over-walks” exist over the revetments.
Access along the beach is entirely dependent upon the beach width, which is, in
turn, dependent upon the local sediment supply in the littoral system, which is
not favorably impacted by the revetments.
How do you expect the 2002 revetments, if
left in place (i) for two years and (ii) permanently to affect access to and
along the beach and the availability of sandy beach for recreation.
In the event that the revetment is left in place
for two years or permanently, the revetment can be expected to (a) deprive the
littoral system of about 14,000 cubic yards per year and (b) result in
narrowing of the beach seaward of the revetment at about 20 feet per year.
Yes, it might be physically feasible to relocate some park improvements further landward to avoid and minimize impacts to the natural beach. Another alternative with fewer impacts is beach nourishment, which would have a lesser impact upon the beach.
Are there regional or watershed-based
approaches that could reduce erosion without employing hard structures?
Yes, the 2002
M&NE Report cites that “Debris
basins in Goleta Slough and its tributaries now trap significant quantities of
sediment in flood years.” As part of maintenance, beach compatible sand from
these debris basins might be removed from the basins and placed on the beach.
No, I cannot map “the mean high tide line at Goleta Beach”. A surveyor is most appropriately engaged to map the “mean high tide line” or mean high water line. With sufficient pre-construction/post-construction surveys and/or construction plan, I can offer an opinion as to the location of the revetments relative to the MHTL at the time of revetment construction. Unfortunately, I am not aware of such surveys or plans.
Based on the available evidence as cited above, the causes of erosion at Goleta Beach appear to be almost entirely due to insufficient longshore sediment transport into the Goleta Beach area from the shoreline to the west of the UCSB bluff and Goleta Point. Based on the reported sediment contribution to the littoral system attributable to bluff or cliff erosion, between 1% and 25% of the erosion may be attributable to the effects of revetments, seawalls, and other shoreline armoring structures that deter or prevent bluff erosion.
If you have any questions, or if I may assist you further, please contact me.
Sincerely,
COASTAL TECH
Michael Walther, M.S.
P.E. - FL, TX, LA, NC, AL
Michael Walther,
President of Coastal Tech, serves as Principal-In-Charge and Quality Assurance
Officer. Michael leads negotiation of
project agreements and any necessary amendments. Michael also provides guidance
and assistance to Coastal Tech’s Project Managers and Project Teams. Michael coordinates
project personnel, establishes schedules, monitors compliance with these
schedules, reviews the technical quality of the work; and ensures that all work
is completed on time and within budget.
Michael provides expert witness testimony in cases relative to coastal
and marine construction.
Michael has proven
his detailed understanding of coastal processes, environmental permitting,
engineering economics and funding for erosion control projects and beach and
inlet management. Michael has prepared
erosion studies, benefit/cost analysis and designs for shoreline stabilization,
inlet management, and beach and dune restoration projects.
Michael has
supervised design, permitting, and construction phase services for numerous
shoreline stabilization projects including, revetments, bulkheads, seawalls,
and wetlands vegetation. Michael has extensive experience in the design of
wood, aluminum, steel, and reinforced concrete marine structures.
Michael currently
serves as a "Coastal Consultant" for Volusia, Bay, and Santa Rosa
Counties, the Florida Department of Environmental Protection, the Port of Bay
City Authority, the State of Texas General Land Office, the cities of Venice
and Sarasota, and the Town of Palm Beach. Michael is a registered professional
engineer licensed in the states of Florida, Texas, Alabama, North Carolina, and
Louisiana.
M.S. - Ocean
Engineering, 1977
University of Texas
At Austin
B.E.S. - Engineering
Science, 1975
University of Texas
At Austin
1984 - Present: President
Coastal Tech
1978 - 1984: Coastal
Engineer/Area Manager
Arthur V. Strock
& Associates
1976 - 1977: Teaching Assistant
University of Texas
At Austin
(Hydraulics Lab)
1974 - 1976: Research Assistant
University of Texas
At Austin
(Coastal Zone Studies)
American Shore &
Beach Preservation Assoc.
American Society of
Civil Engineers
Florida Engineering
Society
Florida Institute of
Consulting Engineers
Phipps Ocean Park
Beach Restoration
McFaddin
National Wildlife Refuge Beach
Restoration
Surfside Beach Dune
Restoration
Martin County Sand
Transfer Implementation
St.
Lucie County Beach Restoration/Erosion
Control
City of Venice Beach
Restoration
Parker’s Cut Initiative
Indian River County
Economic Analysis
John's Island Dune
Renourishment (Hydraulics
Lab)
Brevard County Beach
Management Plan
John U. Lloyd Beach Restoration
Coral Cove Park
Beach/Dune Nourishment Plan
Sebastian Inlet
Management Plan
Harbor
Branch Maintenance Dredging and
Infrastructure Master Plan
Sebastian
Inlet Maintenance Dredging and
Feeder Beach
St.
George Island State Park Master Plan and
Post Hurricane Opal Restoration
John's
Pass Inlet Management Plan
Page 2
“Coastal Sediments - A Valuable Natural Resource,” Walther, M.P., Coastal Zone 99, 1999.
“Inlet Effects - Downdrift Translation by Natural and
Artificial Headlands,” Walther,
M.P., 8th Annual National Conference on Beach Preservation Technology,
1995.
“Looking for Sand Sources Further Offshore Case Study:
Venice Phase II,” Walther,
M.P., 8th Annual National Conference on Beach Preservation Technology,
1995.
"Use of Ebb Shoal Borrow Areas," Walther, M.P. and Douglas, B. D., 6th Annual National
Conference on Beach Preservation Technology, 1993.
"Ebb Shoal Borrow Area Recovery," Journal of
Coastal Research, Special Issue No.
18, pp. 211 - 212, Fall 1993.
“Sebastian Inlet Sand Transfer Performance," Walther, M.P., Douglas, B.D. and Fitzpatrick, K., Proceedings
of the 1992 National Conference on Beach Preservation Technology, pp.
293-309.
"Sorting Characteristics of Tidal Inlets," Walther, M.P. and Douglas, B.D, Proceeding of Coastal
Sediments '91, Vol. 2, pp. 1462-1475.
"Dune Maintenance," Walther, M.P., Proceeding of Coastal Zone '91, Vol.
1, pp. 235-245.
"Inlet Sand Transfer," Walther, M.P., Proceeding of Coastal Zone '89, Vol.
2, pp. 1711-1723.
"Economics
of Sand Transfer," Walther,
M.P., Sasso R.H. and Lin, C.P., Proceeding of Beach Preservation Technology
'89, pp. 199-207.
MICHAEL PAUL WALTHER, M.S., P.E.
EXPERT WITNESS TESTIMONY EXPERIENCE
|
Year |
Case |
Attorney |
Nature
of Testimony |
|
1985 |
Clifford A. McNulty vs. Town of
Indialantic |
Joseph S. Gillen,
Jr. |
Feasibility of
permitting and construction of an oceanfront structure to withstand a 100
year storm event. |
|
1986 |
Town of Highland
Beach vs. Royal
Highlands Development |
Richard B. Barkin |
The capability
of a proposed oceanfront seawall to withstand a 100 year storm event. |
|
1990 |
Drexel Investments,
Inc. vs. Town of
Highland Beach |
David K. Friedman |
Processing of
permits obtained by Drexel for marina construction and marine wetlands
alteration. |
|
1992 |
Broadview Savings
Bank et. al. vs. Town of
Highland Beach |
George P. Roberts,
Jr. |
Processing of
state and federal permits for marina construction and marine wetlands
alteration. |
|
1992 |
2800 SE Dune Drive
Condo vs. Mobil
Corporation |
Gary C. Rosen |
Necessity of
shoreline stabilization at Sailfish Point. |
|
1993 |
Andrew Machata and Neil Lazendorf vs. State of
Florida DNR |
Thomas Tomasello |
DEP permit
requirements for an oceanfront seawall and DEP Rule challenge. |
|
1993 |
Reynolds et. al. vs. Volusia County |
Daniel D. Eckert |
Public access
and beach shoreline changes. |
|
1996 |
Applegate et. al. vs. United State
of America |
J. Mason Williams,
III. |
Impact of Port
Canaveral Inlet upon adjacent beachfront properties. |
|
1996 |
George and Miriam
Young vs. Department of
Environmental Protection and North America
Consolidated Corporation |
Enola Brown |
DEP permit
requirements for an oceanfront home. |
|
1997 |
Dames & Moore vs. Siegel-Robert,
Inc. |
Christopher
Schilling |
Oceanfront revetment
design - standards of practice. |
|
Year |
Case |
Attorney |
Nature
of Testimony |