DESK TOP STUDY
FOR THE VIRGIN ISLANDS WATER AND POWER AUTHORITY’S
PROPOSED
UTILITY CABLE CONNECTIONS BETWEEN
FAJARDO, PUERTO RICO AND KRUM BAY, ST. THOMAS
KRUM BAY, ST. THOMAS AND RED HOOK, ST. THOMAS
RED HOOK, ST. THOMAS AND WEST END, TORTOLA
KRUM BAY, ST. THOMAS AND CHRISTIANSTED, ST. CROIX
PREPARED BY
BIOIMPACT, INC
AND
STEARNS WEAVER MILLER WEISSLER ALHADEFF & SITTERSON, P.A.
NOVEMBER 2010
i
Fiber Optical Submarine Cables as Depicted by Alcatel 2010
ii
iii
Chart Encompassing Entire Project Area
iv
TABLE OF CONTENTS
page
1
Introduction
General Considerations Project Wide
2
Climate and Weather
3
Geology and Seismic Considerations
8
Sea Conditions
Tides and Currents
Waves
Water and Seafloor Temperature
12
12
13
15
Area Wide Environment Considerations
18
Route Selections
Discharges
Navigation Route
19
19
19
Detailed Descriptions of Individual Routes
Fajardo, Puerto Rico to Krum Bay, St. Thomas
Krum Bay, St. Thomas to Red Hook, St. Thomas
Red Hook, St. Thomas to West End, Tortola
Krum Bay, St. Thomas to Christiansted, St. Croix
21
21
28
31
34
Permit Requirements
37
Information Needed for Permitting
39
References
41
Appendix A - List of Active Submarine Cables
Appendix B - Latest Charts
http://www.charts.noaa.gov/OnLineViewer/AtlanticCoastViewerTable.shtml
Appendix C – NMFS and FWS Guidance Documents
Appendix D - Obstruction Updates
v
INTRODUCTION
Bioimpact, Inc. and Stearns Weaver Miller Weissler Alhadeff & Sitterson, PA, were contracted on
November 5, 2010 to complete an abbreviated Desk Top Study for the utility cable system being
proposed by the Virgin Islands Water and Power Authority. The purpose of the system is to
interconnect the electrical service and provide fiber optic capacity between Virgin Islands and
Puerto Rico as well as the British Virgin Islands.
The Desk Top Study identifies the most feasible routes and landing points between the islands.
This Desk Top Study includes;
 The available bathymetric charts which depict the maximum sea depth for each of the
proposed interconnections.
 The environmental conditions along each route including the data on seas, winds and
water quality conditions including maximum ambient temperature in the water column
and the available seabed temperature (near shore section of the route).
 A discussion of areas where near shore cable burial may be permissible and areas where
burial will not be possible due to environmental or geological conditions.
 Available information regarding the variable seabed conditions and topography, including
rocky outcrops, coral reefs, scarp slopes and marine channels and areas of known current.
 The report describes major fishing and shipping activities and anchorages in the vicinity of
each route.
 The report includes the available information on wrecks and dumping areas.
 The report includes the most current information available from the United States Coast
Guard (USCG) in regard to the existing submarine pipelines and cables.
 The report will includes a general discussion of the geology of the routes including a
discussion of faults and earthquakes centers.
 The report identifies all publicly known discharges within the area whether natural or
man-made which might impact the cable routes.
 The report identifies to the greatest extent possible all activities proposed within the cable
corridor which could impact the cable.
1
 The report describes in general the Environmental issues associated with the route
including but not limited to coral reefs, endangered species, essential fish habitat and
protected habitats.
 The report includes a detailed listing or all Consents and Permits, both federal and local to
the U.S.V.I. and Puerto Rico which will be required as well as the permits which will be
required for the West End, Tortola Landing.
GENERAL CONSIDERATIONS
PROJECT WIDE
The proposed system spans a portion of the northern section of the Antilles Island Chain. The
waters are shallow between Puerto Rico, St. Thomas and the British Virgin Islands and there are
no significant slopes or scarps. The crossing to St. Croix is far deeper but careful routing can
avoid the deepest areas of the crossing and the areas with the steepest slopes. The Routes
discussed in this survey have been developed by evaluating sea floor depths and conditions,
environmental resources, infrastructure, obstructions (natural and manmade), and permitablility.
The following information affects all routes within the proposed system, route specific
information is provided in the detailed description of each route.
Climate and Weather
Prevailing Winds
Puerto Rico and Virgin Islands lie in the “Easterlies” or “Trade Winds” which traverse the
southern part of the “Bermuda High” pressure area, thus the predominant winds are usually from
the east-northeast and east (IRF, 1977). These trade winds vary seasonally (Figure 1) and are
broadly divided into 4 seasonal modes: 1) December to February; 2) March to May; 3) June to
August; and 4) September to November. Below are the characteristics of these modes as taken
from Marine Environments of the Virgin Islands Technical Supplement No. 1 (IRF, 1977).
December – February
During the winter the trade winds reach a maximum and blow with great regularity from the eastnortheast. Wind speeds range from eleven to twenty-one knots about sixty percent of the time in
January. This is a period when the Bermuda High is intensified with only nominal compensation
pressure changes in the Equatorial Trough. The trade winds during this period are interrupted by
“Northerners” or “Christmas Winds” which blow more than twenty knots from a northerly
direction in gusts from one to three days. Such outbreaks average about thirty each year. They are
created by strengthening of high-pressure cells over the North American continent, which, in turn,
allow weak cold fronts to move southeastward over the entire Caribbean region. These storms are
accompanied by intermittent rains, clouds and low visibility.
3
March - May
During the spring, the trade winds are reduced in speed and blow mainly from the east. Winds
exceed twenty knots only thirteen percent of the time in April. The change in speed and direction
is the result of a decrease of the Equatorial Trough.
June - August
Trade winds reach a secondary maximum during this period and blow predominantly from the
east to east-southeast. Speeds exceed twenty knots twenty-three percent of the time during July.
The trend for increasing winds results from the strengthening of the Bermuda High and a
concurrent lowering of the pressure in the Equatorial Trough. Trade winds during this period are
interrupted by occasional hurricanes.
September - November
During the fall, winds blow mainly from the east or southeast and speeds reach an annual
minimum. Only seven percent of the winds exceed twenty knots in October. The low wind
speeds result from a decrease in the Equatorial Trough. During this period, especially during late
August through mid-October, the normal trade wind regime is often broken down by easterly
waves, tropical storms and hurricanes.
Storm and Hurricanes
There are numerous disturbances during the year, especially squalls and thunderstorms. These
occur most frequently during the summer, lasting only a few hours and causing no pronounced
change in the trade winds.
A tropical cyclone whose winds exceed 74 miles per hour is termed a hurricane in the northern
hemisphere, and significantly affects the area. These hurricanes occur most frequently between
August and mid-October (Figure 3) with their peak activity occurring in September. The annual
probability of a cyclone is one in sixteen years (Bowden, 1974). The passage of hurricanes are
responsible for damage to coastal structures, grounding of vessels and movement of seafloor
sediments and the burial and exposure of existing cables and pipelines. The 2010 season has been
a very active one with numerous storms effecting Puerto Rico and the Virgin Islands.
4
Figure 1A: Prevailing Winds, January through June
5
Figure 1B. Prevailing Winds, July through December.
6
Figure 3. Tropical Hurricane Frequencies in Puerto Rico, and the Virgin Islands (National
Weather Service).
Figure 4. Tropical Storm and Hurricane Occurrences in the Atlantic (National Weather Service)
7
GEOLOGY OF PUERTO RICO AND THE VIRGIN ISLANDS
Puerto Rico and the Virgin Islands are near the northeastern corner of the present Caribbean Plate,
a relatively small trapezoidal-shaped plate that is moving eastward relative to the North and South
American continents carried on the American plate. The arc of the Lesser Antilles is an active
volcanic arc above a subduction zone in which the Atlantic oceanic crust of the American Plate is
carried downward under the Caribbean Plate. The closest volcano to the Virgin Islands that is still
active is Saba, about 160 km. to the east.
St. Thomas and its off-lying cays are composed of stratified volcanic and volcaniclastic rocks with
minor limestone of the Early Cretaceous (Albain) to possibly the late Cretaceous Age (Donnelly
1966). These rocks are granitic composition, some of which may be as young as Tertiary (Kesler
and Sutter, 1979). The oldest rocks of St. John are submarine lavas (keratophyre and spilite), beds
of volcanic debris and chert. Associated intrusive rocks of the Water Island Formation are
overlain by andesitic volcanic and volcaniclastic rocks of the Louisenhoj Formation which
underlies the island of St. Thomas to the east and much of the northwestern portion of St. John.
Donnelly (1966) suggested that the Louisenhoj Formation was deposited unconformably on the
Water Island Formation after a period of emergence, tilting and erosion, on the slopes and
environs of a sub aerial volcanic island located roughly between St. Thomas and St. John, an area
now occupied by Pillsbury Sound. The youngest layered deposits on St. Thomas are
volcaniclastic rocks of the Tutu Formation. Fossils contained in the Tutu Formation suggest that
those deposits are of the Early Cretaceous (Albain) Age (Donnelly et. al. 1971). It appears that all
of the volcaniclastic rocks of St. Thomas were deposited in a relatively short period of time
spanning 10 to 15 million years approximately 100 million years ago (D. Rankin 1988).
The Puerto Rican bank which was created by the volcanism as described above during the
Cretaceous became emergent through orogenic movements in the lower Eocene (Meyerhoff,
1933). Sea level has been variable, and during the Oligocene sea level was 150 meters lower than
present day sea level which made Puerto Rico and the Virgin Islands (less St. Croix) a continuous
landmass.
The seafloor between Puerto Rico and St. Thomas is relatively shallow, and level. There are
scattered coral reefs and small rises. No trenches or significant changes in depth occur along the
routes. The seafloor is also relatively shallow and level around St. Thomas and through the island
chain to Tortola. There is a significant trench between St. Croix and St. Thomas, the presence of
this trench has resulted in the cable being routed to the east to avoid extreme depths.
SEISMIC ACTIVITY
Puerto Rico and U.S. Virgin Islands lie in one of the most earthquake prone areas of the world,
and are susceptible to ground shaking, earthquake-induced ground failures, surface fault ruptures
and tsunamis (tidal waves) (Hays, 1984). The activity is mostly associated with large-scale
tectonic activity or faulting, originating in the Anegada Trough to the northeast of the islands. The
trough and its related scarp apparently were thrown up by block faulting during the late Pliocene
8
or early Pleistocene. It is oriented generally northeast to southwest, separating St. Croix from
Puerto Rico and the other Virgin Islands. Based on shallow focus earthquakes, the Anegada Fault
Trough is estimated to be more than 400 miles in length. There are indications that strike slip
movement is occurring, with St. Croix shifting northeast relative to Puerto Rico (Puerto Rico
Water Authority 1970). The year 2010 marks the 143th anniversary of the last major earthquake
in the Virgin Islands. This quake, which occurred on November 18, 1867 had an identified
intensity of VIII on the Modified Mercalli Scale. Earthquakes of this magnitude have generally
been associated with epicentral ground accelerations of between 0.05 and 0.35 gravities. Since the
1867 quake, there has been continuous low intensity activity, all below 6.0 Richter. The last
destructive shock in Puerto Rico was in 1918 (7.5 Mercalli Scale), did not occur along the main
seismic zone, but rather on an intraplate fault near Mona Canyon off the northwest coast. A
possible great earthquake in 1787 (8 to 8.25 Mercalli Scale) appears to have occurred along the
main seismic zone near the Puerto Rico Trench to the north of the island, but data for the event are
scarce. Thousands of tiny earthquakes are encountered every year in the islands. This activity is
associated with the volcanic eruptions that have been occurring to the southeast on the island of
Monserrat.
Seafloor morphology, microearthquakes, and the record of historic earthquakes define a zone of
deformation extending from the Puerto Rico Trench, northeast of the Virgin Islands, trending
southwest along the Anegada Trough and then westerly along the Muertos Trough. The Muertos
Trough is the locus of convergence between the floor of the Caribbean Sea and Puerto Rico.
Maximum dimensions of future large earthquakes are inferred from sizes of blocks in the
Anegada and Muertos Troughs as well as Mona Canyon. Shocks as large as 7.5 Mercalli Scale can
occur on these intraplate faults. Although strain rates on these faults may be an order of magnitude
less than on faults in the Puerto Rico Trench, the large number of potential sources suggest that
damaging earthquakes in this part of the Caribbean can come from either the Puerto Rico Trench
or the intraplate faults with nearly equal probability.
Seismic information from 1990 to 2003 from Puerto Rico Seismic Network is presented below:
2003
During 2003 the PRSN located 947 tremors, which represents a decrease of 2.07%
compared to the previous year (2002, 967 tremors). This level of seismic activity is
considered normal assuming an average of 2 ± 1 tremors daily. Like the previous year, the
month with the most activity was March with a total of 115 tremors (2002, 98 tremors),
while the lowest was January with only 51. Of all the seismic activity, only 26 tremors
(27%) were reported as felt. Of these 26, 2 tremors (May 14 and September 22) were
generated outside of the PRSN, and were located by the NEIC/USGS. The tremor of the
greatest magnitude (6.5 on the Richter scale) occurred on the 22nd of September at
00:45:50 (local time). This tremor was felt throughout the entire Dominican Republic and
in Puerto Rico. It was located 15Km northeast of Puerto Plata and approximately 410Km
northeast of Mayaguez, at latitude 19.847° N and longitude of 70.666° E, with a depth of
10.0 Km. The maximum intensity was VII (Modified Mercalli Scale) in Puerto Plata,
Dominican Republic and V in Puerto Rico . The majority of reported seismic activity this
9
year ocurred in the southeast region of Puerto Rico, with a total of 9 tremors, followed by
the Virgin Islands platform, which registered 7. The month with the most tremors was
March, with a total of 9.
2002
During 2002 the PRSN located 967 earthquakes, a number exactly equal to the number of
earthquakes in the previous year. Of the total seismicity, only 22 earthquakes (2.2%) were
reported felt. The month of greater seismic activity was March, with a total of 98
earthquakes, and the one with smallest activity was February with 61 earthquakes. The
earthquake of greatest magnitude (4.7 in the Richter Scale) happened on the 13 of
November at 16:27:49, and was felt in the Virgin Islands and in all Puerto Rico. This
earthquake was located 35 km to the Northeast of Anegada, at the latitude 18.97° N and
the longitude 64.17°W, with a depth of 25.6 km and a maximum intensity of IV (Modified
Mercalli Scale) in Anegada. The earthquake of greatest intensity (V in Modified the
Mercalli Scale, the central area and east of the island) happened on the 20 of June at
11:24:24, and was felt almost all over the island of Puerto Rico. This earthquake was
located in the municipality of Naranjito, latitude 18.244° N and longitude 66.286°W, with
a depth of 6.2 km and a magnitude of 4.0 in the Richter Scale. Most felt earthquake were
concentrated in the Virgin Islands and the Seismic Zone of the Sombrero, although the
month with more felt earthquakes was June. Seismicity was widely distributed this year,
although there were, as usual, greater concentrations in The Sombrero seismic zone and in
southwestern PR. October to November saw the greatest amounts of seismic energy
release.
2001
During the year 2001, 967 seismic events were reported, representing an increase of 30%
relative over the previous rear. The month with the greatest amount of activity was
October with a total of 204 events, while the month with least activity was June with only
51 events. Out of the total seismicity for this year, only 2% were reported as felt (a total of
20 events). The earthquake of October 17 was the event of highest magnitude (5.2 on the
Richter scale) and the most intense (V on the Modified Mercalli scale). The areas with the
highest concentration of seismicity were the Sombrero seismic zone, the area north of
Culebra and Virgin Islands, and the southwest region of Puerto Rico. 54.6% of the total
energy released during this year was released during October in the swarm at the
Sombrero seismic zone.
2000
During year 2000, 735 events were located, representing an increase of 20.2% relative to
the previous year (586 earthquakes in 1999). The month of greatest activity was May with
51 events. Of these, only 2.3% were reported as felt. The earthquake on December 11, was
the event of greatest magnitudes (4.9 Richter Scale) and intensity (IV Modified Mercalli
Scale). The seismicity in the region was quite scattered, although with a greater
concentration in the Island and towards the north, east and west of the local region. Within
10
the island, the most active region is to the south of an imaginary line that connects Rincón
to Guayama.
1999
Five hundred and eighty six earthquakes were located by the PRSN in 1999. The month of
highest seismic activity was November, with a total of 65 events; the month of lowest
seismicity was April, with 37 earthquakes. Nineteen felt events were reported this year.
Two (February 27th and March 7th) had magnitude of 4.7, the highest for the year. The
strongest felt event was the January 18th earthquake, with a maximum intensity of V on
the Modified Mercalli Scale. The seismicity for the Puerto Rico region during 1999 was
distributed rather evenly, with a slightly higher concentration of events on the on the
northern, eastern and western portions of this area. Inland, the southwestern part of the
island showed the highest seismic activity.
1998
The PRSN located 622 earthquakes during 1998. There were concentration of earthquakes
north of the Virgin Islands in the Sombrero Seismic Zone, to the north of Puerto Rico,
south of Vieques and within the island, in the south. Thirteen of the earthquakes were felt,
the one of largest magnitude (5.6) occurred December 7 and was located just south of
Anegada, while the earthquake that was felt strongest (MM=V) occurred just offshore of
Manatí on August 28 and had a magnitude of 4.4.
1997
The PRSN located 469 earthquakes in the Puerto Rico region for 1997. Of these events,
only six were reported to have been felt, the largest of which occurred March 31 with a
magnitude of 4.7 and was located in the Eastern Dominican Republic. The earthquake was
felt the strongest took place on July 31 at 10:35 AM and had an intensity of IV on the
Mercalli Modified Scale and was located just north of Arecibo. The PRSN also processed
130 regional earthquakes and 307 teleseismic events
1996
The PRSN located 721 earthquakes in the Puerto Rico region for 1996. Fifteen of these
earthquakes were felt, of these, six were located in southwestern Puerto Rico. The largest
felt event occurred May 10 and had a magnitude of 5.1. The event was felt the strongest
(V MM) was located in Cabo Rojo. The PRSN also processed 114 regional earthquakes
and 418 teleseismic events.
1995
The PRSN located 644 earthquakes in the Puerto Rico region. Seventeen of these
earthquakes were felt; of these, eight were located in southwestern Puerto Rico. The
largest felt event had a magnitude of 4.6 and it's epicenter was located 80 Km north of
Isabela, just east of the mouth of the Mona canyon. No earthquake was reported to have
11
caused damage, six of the felt events had maximum intensities between IV-V (Mercalli
Modified Scale). The Puerto Rico Seismic Network also processed 149 regional
earthquakes and 348 teleseismic earthquakes.
1994
The PRSN located 816 events in the PR region. Twelve were felt, the largest occurred
September 22 and had a magnitude 5.0. Nevertheless, the one felt more strongly occurred
September 12 in Boqueron, southwestern PR where it had a maximum intensity of V.
1993
The PRSN located 787 earthquakes in the PR region. Seven events were felt, the largest of
these being one of magnitude 5.0 which occurred in the Muertos Trough southeast of the
island. The Network also processed 127 regional and 248 teleseismic earthquakes.
1992
The PRSN located 678 earthquakes in the Puerto Rico region during 1992. Although the
number of earthquakes located greatly exceeds the earthquakes located in previous years,
they occurred in areas where the greatest seismic activity has taken place historically and
can be related to the oblique subduction of the North American plate under the Caribbean
plate. Only 4 of these earthquakes were felt in the region.
1991
During 1991 there were 364 local earthquakes registered by the network. The largest
concentration of earthquakes occurred on a north-south belt from the Puerto Rico trench to
southern Puerto Rico along longitude 67 W. The seismic network processed 300
teleseismic and 106 regional events.
1990
During 1990 there were 314 local earthquakes registered by the network. The largest
concentration of earthquakes occurred to the northeast of the island. The seismic network
processed 322 teleseismic and 72 regional events.
SEA CONDITIONS
Tides And Currents
Tides in the eastern Caribbean are of low amplitude (on the order of 1 meter or less) as there is an
"amphidromic" point nearby in the central eastern Caribbean around which the tidal wave travels.
At this point, the tidal amplitude is by definition zero. The Caribbean amphidromic point is about
200 km south of Puerto Rico. Tides in the Caribbean are diurnal with one low and one high per
day while tides in the Atlantic are semidiurnal with two lows and two highs per day. Tidal motion
can account for a significant fraction of the total observed current. Tidal currents can be
substantial. Tides are measured at coastal sea-level stations operated by NOAA and the Puerto
Rico Seismic Network.
12
Observed Data and Graphical Predictions are available for the following stations within the
project area:
9751364 Christiansted Harbor, St Croix, VI
9751381 Lameshur Bay, St. John, VI
9751639 Charlotte Amalie, VI
9752235 Culebra, PR
9752695 Esperanza, Vieques Island, PR
9731540, Redhook Bay, St. Thomas, VI
The tidal station located in Redhook Bay (ID 9731540, NOAA 2003) records the mean tide as
0.81”.
The tidal ranges of the station are as follows:
Mean Higher High Water
Mean High Water
Mean Tide Level
Mean Sea Level
Mean Low Water
Mean Lower Low Water
1.09’
0.94’
0.54’
0.52’
0.13’
0.0’
In 1995 during Hurricane Marilyn the Charlotte Amalie (9751639) tide station recorded the
highest tide height 3.98’ above Mean Lower Low Water.
The surface currents throughout the Caribbean are driven by the North Equatorial Current which
runs through the islands west-northwest and then joins the Gulf Stream (Figure 3). These currents
change very little from season to season with the currents coming more from the south during the
summer months. Because of the shallowness of the Caribbean basin, less than 1000 m, mainly
surface water from the Atlantic flows through the islands. The westerly drift of the Caribbean
current sweeps into the passage between Puerto Rico and the Virgin Islands and into Pillsbury
Sound from the southeast, seeking a way north through the barrier set up by the cays to discharge
along the north shore of Puerto Rico, St. Thomas and out into the Atlantic (Figure 7).
Currents within the Inner Passage are reported to run on average between one to two knots with a
maximum of 7 kt. currents being recorded.
Waves
The deep-water waves off the islands are primarily driven by the northeast trade winds which
blow most of the year (Figure 8). Waves average from one to three feet, from the east, 42% of the
time throughout the year (IRF, 1977). For 0.6% of the time easterly waves reach 12 ft. in height.
The southeasterly swell with waves one to 12 feet high become significant in late summer and fall
when the trade winds blow from the east or
13
when tropical storms and hurricanes pass the islands at a distance to the south. During the winter
months, long length, long period northern swells develop to a height of one to five feet.
Information hindcast at WIS station L1-12 revealed that between January 1990 and December
1999 waves approached from between north and east 98.4 percent of the time. Significant wave
heights were less than 6.6 feet for 63.7 percent of wave cases recorded and less than 10 feet for 96
percent of the cases recorded. Peak wave periods were between five and 10 seconds for 62
percent of all recorded cases. The most extreme wave conditions recorded were in September
1995 when a 44 foot wave with a 15 second period approached from the northwest. This event
was likely associated with Hurricane Marilyn.
Waves approaching through Pillsbury Sound (between 124 and 146 degrees) were recorded by
station L1-12 only 0.11 percent (97 cases) of the time between 1990 and 1999, half of which had a
significant wave height of 6.6 ft. (2 meters) or less. Significant wave heights of 16.4 ft. or greater
were recorded only 0.01 percent (18 cases) of the time. Peak wave periods from this direction
were widely distributed, with the majority of cases being between four and nine seconds.
The number of recorded waves coming from the north, north-northeast, northeast, east-northeast,
and east according to station L1-10, are listed in the table below. Of primarily concern as far as
waves entering Middle Passage are those waves from the north to northeast, between 349 and 56
degrees. While occurrences of such waves were significant between 1990 and 1999, 36.3 percent
of all cases, the majority had significant wave heights of less than 10 feet. Peak wave periods
from the north and north-northeast directions tended to be the longest with the largest number of
cases in the 11 to 14 second range.
DIRECTION
ALL
N (349 TO 11)
N-NE (11 TO 34)
NE (34 TO 56)
E-NE (56 TO 79)
E (79 TO 101)
NUMBER OF
CASES
87632
3573 (4%)
8025 (9.2%)
20229 (23.1%)
36762 (42%)
16833 (19.2%)
LESS THAN 10 FT.
84087 (96%)
2910 (81.4%)
7300 (91%)
19383 (96%)
35907 (98%)
16085 (96%)
Waves approaching the Leeward Passage from the northwest (between 281 and 304 degrees)
seldom occur. According to station L1-10, between 1990 and 1999, only 25 wave cases (out of
87632) took such an approach. Peak wave periods from this direction were significant; 18 of the
25 cases had wave periods equal to or greater than 11 seconds. The largest wave case recorded at
L1-10 came from the northwest (325 degrees).
The majority of extreme wave cases, significant wave heights greater than 13 feet (4 meters),
come from the north, northeast and east. The wave periods for these extreme waves are usually 10
seconds or greater. Between 1990 and 1999, the months from November to March had the
highest mean wave heights, greater than 6.9 feet.
14
Water and Seafloor Temperatures
Water temperatures in the Virgin Islands and Puerto Rico do not change greatly from summer to
winter. In the summer months the water temperature is about 83 degrees and in the winter about
79 degrees. Seafloor temperatures have been found to be equivalent to water temperatures during
Environmental Assessments conducted in the Virgin Islands and during Total Maximum Daily
Load Studies for the Environmental Protection Agency, (Bioimpact, 2009).
Figure 5 Tides recorded in St. Thomas Harbor, IRF 1975.
15
Figure 6. Tides recorded in Christiansted Harbor IRF 1977.
Figure 7 Prevailing currents in the Caribbean, IRF 1975.
16
Figure 8 Prevailing current in the Virgin Islands IRF 1977.
Figure 9. Average sea and swell conditions for Puerto Rico and Virgin Islands Coastal
areas.
17
AREA WIDE ENVIRONMENTAL CONSIDERATIONS
The marine environment surrounding Puerto Rico and the Virgin Islands is one of the richest
environmentally in the world. The tropical systems support coral reefs, and vast seagrass beds.
These systems support a variety of endangered and threatened species, create essential fish habitat
and are critical for commercial fishing. The warm Caribbean waters are home to endangered sea
turtles, manatees and marine mammals.
Large areas around the Virgin Islands and Puerto Rico, as shown below, have been designated
Critical Habitat for Elkhorn (Acropora palmata) and Staghorn (Acropora cervicornis) corals.
Puerto Rico and Associated Islands
St. Thomas and St John
18
St. Croix Area
Marine Mammal Protection Act
The Antillean Manatee occurs primarily in the shallow water near Fajardo, however it is possible
that manatees may be encountered near Vieques or farther east. Whales and dolphins are known
to occur throughout the project area. During the placement of the cables adherence to guidelines
to protect these species will be required. National Marine Fisheries and Federal Fish and Wildlife
have developed Standard Manatee Conditions for In-Water Work, Standard Sea Turtle Conditions
for In-Water Work and Standard Marine Mammal Conditions and Guidelines for In-Water Work
(Appendix C). These guidelines lay out special monitoring, and avoidance measures to ensure the
survival of these animals.
ROUTE SELECTION
The routes selected are the shortest routes available while following the basic guidelines set forth
by the U.S. Army Corps of Engineers, avoiding impacts to marine plants and animals where
possible and where impacts are not avoidable minimizing those impacts.
Where possible extremely depths are avoided, and shallow areas, obstructions and anchorages are
avoided.
Discharges
There are no discharges along any of the routes which should impact the cables.
Fishing Areas
There are no fishing areas or methods along the routes which should impact the cables.
19Navigation Routes
The proposed cable routes are within areas which are frequented by cruise ships, commercial
traffic as well as recreational craft. The West Gregerie Channel, Red Hook Channel and
Christiansted Channel are all heavily used. Lays will need to be coordinated with the Virgin
Islands Port Authority Marine Division, the Department of Planning and Natural Resources,
Division of Environmental Enforcement and the U.S. Coast Guard.
Cable Burial
The burial of submarine cables throughout the region where submerged aquatic vegetation is
present is not looked upon favorably by the permitting agencies. Where inshore sections require
burial mitigative measures must be taken to minimize impact and mitigation is often required.
The cables tend to self-bury over short time periods depending on currents and storm events.
GCN-1 Cable in articulated pipe is buried within 15’ of entering the sand, this self-burial occurred
in less than 2 months (Bioimpact 2006).
The St. Thomas – St. John Power cable has self-buried beneath the seagrass beds.
20
DETAILED DESCRIPTIONS OF INDIVIDUAL ROUTES
FAJARDO, PUERTO RICO TO KRUM BAY ST. THOMAS
The route would originate in Fajardo, Puerto Rico and pass between the reefs around Cayo Icacos
and Cay Lobos to the north before turning to the east towards St. Thomas. The cable has been
routed to the north to water deeper than the designated critical habitat for Acropora and deeper
than the habitat areas which will potentially be designated for 7 additional coral species which are
in the process of being placed on the Endangered Species List (50 CFR Parts 223 and 224). The
cable route goes to the north of areas of concern associated with the Navy’s use of Vieques. As
stated by Stacin Martin, NAVFAC Atlantic EV31, “With regards to Vieques and any restricted or
potentially hazardous areas your locations are well outside or away from Vieques. However, you
should consult the NOAA charts for other restricted areas (some related to past military use). The
locations provided on the photos are in the vicinity of some of these known areas, but it is difficult
to tell exactly without geographic reference.” The route will cross a number of cables which pass
between St. Thomas and Savana Cay off of St. Thomas. The route will stay well off shore of the
Cays off the west end of St. Thomas. The route will then turn north avoiding a designated fishing
area and Porpoise Rocks to follow West Gregerie Channel towards Krum Bay. The route will
cross several old defunct cables coming from Lindbergh Bay and will avoid several sunken
vessels within West Gregerie Channel. The route will be routed to the south of the Krum Bay fuel
pier and to the south of the active St. Thomas Water Island Cable.
21
The following NOAA benthic habitat maps depict the benthic habitats as well as the configuration
of the sea along the route. The vast majority of the route is over sand and only the landing at
Krum Bay is known to be over hard substrate. The hard substrate covers an area of less than
100’from shore.
The deepest depth along the route is approximately 180’.
According to the most up to date charts on the NOAA Office of Coastal Survey website, the route
is outside of the Danger Area 334.140. The route will cross 9 cables near the eastern end of St.
Thomas. The cables the route will cross are: MAC seg 2, St. Croix – St. Thomas Cable, Americas
II Seg A, Americas II Seg B, St. Thomas - Venezuela (2) (1980), St. Thomas – Dominican
Republic, C-1 (1997), GCN-1 (2006) and the JP-VI (1871). It is possible that the route may also
cross the St.Thomas – Martinque cable, however the landing point in St. Thomas could not be
determine at this time. The route will avoid the fish haven to the south of St. Thomas. The route
will also cross up to 3 old cables which originate in Lindbergh Bay, one of which is the JP-VI
(1871). No other obstruction or issues are noted on most up to date charts on the NOAA Office
of Coastal Survey Maps (November 2008) or on their up to date obstruction list (Appendix D).
There are no anchorages or noted fishing areas along the cable route. The area is frequented by
cruise lines and commercial and recreational vessels. Coordination with the Coast Guard and
local marine agencies.will be required avoid conflicts during the cable lay.
22
Chart of cables within the area from PAC Cable Network System, Desk Top Study Chart, 1998.
23
Chart of cables off the west end of St. Thomas from MAC Submarine Cable System Segment 3
(1998)
Chart of the MAC cable system out of the Global Crossing Station (Bioimpact, Inc, 1999)
24
Because of the presence of submerged aquatic vegetation which is considered essential fish habitat
cable burial will be discouraged if not prohibited by the resource agencies. Only at the landing
point in Fajardo where the route will land on a sandy beach will burial be a reasonable alternative
in depths shallower than where the submerged aquatic vegetation exists. If burial is needed to a
deeper depths off shore it is likely that permitting agencies will required special methods to
minimize impacts to the seagrass beds. Articulated pipe should be specified over the length of the
hard bottom in Krum Bay and the resource agencies will require that the cable to secured to the
hard substrate to prevent movement and damage to benthic organism.
25
26
27
KRUM BAY TO RED HOOK, ST. THOMAS
The route originates in Krum Bay to the south of the existing St. Thomas to Water Islands Cable,
the route will follow West Gregerie Channel to south avoiding the wrecks and obstructions in the
channel and Porpoise Rocks. The route avoids the Fish Haven to the south of Porpoise Rocks.
The route traverses to the southeast staying south of Capella Island, Great St. James, Little St.
James and Dogs Rock. The route then turns to the north prior to crossing the St. Thomas – St.
Martin Cable and the Magens Bay – Maiquetia (1966), staying at a depth over 90 ft. and then turns
to the east paralleling the VIWAPA Waterline into the Red Hook Landing. The deepest part of
the route is 108 ft. The route crosses several Innovative Telephone (formerly known as Vitelco)
cables between St. Thomas and St. John; some of the cables are still active, and some area no
longer in use. There are no good records of the location of all the Innovative Telephone cables and
some of the cables have been relocated and damaged by storms.
28
The route will also cross VIWAPA’s Cabrita Power Cable and the Great Bay Power Cable which
both go between St. Thomas and St. John. The route avoids the cable which extends between
Great Bay and Little St. James. No other obstruction or issues are noted on most up to date charts
on the NOAA Office of Coastal Survey Maps (November 2008) or on their up to date obstruction
list (Appendix D).
The cable will stay south of the Cas Cay and Mangrove Lagoon Marine Reserve and east of the St.
James Reserve as shown below.
Marine Reserves in St. Thomas (CZM, 2006)
The habitat maps which also show the seabed conditions for the area follow.
Both terminus of the route are over hard substrate therefore cable burial is not an option.
Articulated pipe should be utilized out to sand on both landings. Cables will need to be anchored
to the substrate to prevent movement and damage to benthic organisms.
29
30
Cables off the East End of St. Thomas (MAC Submarine Cable System Segment 3
(1998))
RED HOOK, ST. THOMAS TO WEST END TORTOLA
31
The route originates in Red Hook to the east of the St. Thomas to St. John utility cable which is
proposed to be lain in early 2011. The route parallels the St. Thomas St. John cable out past Red
Point staying seaward of the near shore hard bottom habitats, the route passes to the north of Two
Brothers following the Windward Passage between Lovango and Durloe Cays. The route stays
outside the Virgin Islands National Park Boundary and Johnson Reef and passes through the
Narrows between St. John and Great Thatch Island. The route passes to the north of Little Thatch
and terminates at an existing cable landing in West End, Tortola.
The deepest point of the passage will be 102 ft.
The route will cross two cable which traverses Pillsbury sound in a north-south direction; St.
Thomas – St. Marteen, and
Magens Bay –Maiquetia (1966). No other obstruction or issues
are noted on most up to date charts on the NOAA Office of Coastal Survey Maps (November
2008) or on their up to date obstruction list (Appendix D).
The following maps show the benthic habitats and the seabed features.
Both landings are over hard substrate so cable burial is not an option. Articulated pipe should be
placed out beyond the hard substrate and should be secured to the seabed.
32
33
KRUM BAY, ST. THOMAS TO CHRISTIANSTED, ST. CROIX
The route will originate in Krum Bay and the route will be established between the cable coming
from Puerto Rico and the cable going to Red Hook. The route avoids the obstructions and wrecks
in West Gregerie Channel and passes out of the channel avoiding Porpoise Rocks and the Fish
Haven to the south. The route traverses to the southeast before turning more easterly to avoid
crossing the deeper portions of the trench between St. Croix and St.Thomas. The route turns
south at a depth of approximately 5350 ft. and slowly turn southwesterly when water depths
shallow to 4500 ft. The route then turns to the west to parallel the St. Croix coastline staying well
outside the National Monument Boundaries and the East End Park Boundaries. The route turns
into the Christiansted Harbor Channel moving to the eastern side of the channel as the water
depths in the channel shallow to 30 ft. The route then follows the Pt. Fort Louise Augusta into the
34
Shoreline to land at the eastern end of Altona Lagoon Beach. According the NOAA Office of
Coastal Survey latest chart of the area the route will cross three other cables, Mac Seg 3a,
Americas II Seg C, and PAC Seg 9. The cable will not cross the St. Thomas – St. Maarten Cable
or the Magens Bay –Maiquetia (1966) cable. The Coastal Survey shows no other obstructions
along the route (Appendix D).
Cables within the area (PAC Cable Network System, Desk Top Study Chart, 1998).
35
Cables originating off the west end of St. Croix (Americas II Cable System, 1999)
The Krum Bay landing is over hard substrate and cannot be buried. The Christiansted landing is
over sandy bottom and the cable can be buried out to the beginning of the seagrass beds. If burial
is required to deeper depths mitigation may be required by the permitting agencies for seagrass
impacts.
The deepest depth of the route will be 7200 ft.
36
PERMITTING REQUIREMENTS
Environmental documentation and permit applications will need to be developed and submitted to
the appropriate regulatory agencies with jurisdiction over the coastal waters for the approval of the
placement of the cables.
The entirety of the Puerto Rico to St. Thomas, Krum Bay to Red Hook and St. Thomas to St.
Croix cables will rest within territorial waters of the United States and federal government has
jurisdiction over such waters. This jurisdiction is exercised by various federal agencies:
•
•
•
•
United States Department of Commerce (National Oceanographic and
Atmospheric Administration - NOAA / National Marine Fisheries Services NMFS),
Environmental Protection Agency (EPA),
United States Department of the Interior (Fish and Wildlife Services – FWS)
United States Army Corps of Engineers (COE) as the leading agency in the
process.
The Puerto Rico Landing and surrounding waters are regulated by the following local agencies
and municipalities of Puerto Rico. These agencies primarily have jurisdiction over the land
portion of the cable. These Puerto Rican agencies are:
•
Department of Natural and Environmental Resources (DNER)
•
Planning Board (PB)
•
Environmental Quality Board (EQB)
•
Institute of Puerto Rican Culture (IPRC)
•
State Historic Preservation Office (SHPO)
•
Subaquatic Archaeological Council (SAC)
•
Ports Authority
•
Municipality of Fajardo
37
The following territorial government agencies from the US Virgin Islands have jurisdiction over
the St. Thomas and St. Croix Landings and cable placements:
•
-
Department of Natural and Environmental Resources (DPNR)
Division of Coastal Zone Management
Division of Environmental Protection
Division of Fish & Wildlife
State Historic Preservation Office (SHPO)
Division of Comprehensive Coastal Planning
•
U. S. Virgin Islands Legislature
In Tortola, British Virgin Islands permits will be required from;



Town and Country Planning
The Planning Board
Conservation Fisheries
Pre-application meetings should be held with both the federal and local agencies of all
jurisdictions noted to present the project and obtain their input.
Environmental Documents will need to be prepared and presented to the applicable federal and
local agencies within the respective districts. Given that the USACE San Juan District has
jurisdiction over both Puerto Rico and the Virgin Islands, a single environmental permitting
document encompassing all submarine routes is desirable by the COE.
In Puerto Rico, if presented and approved by EPA, there will be no need to present the
environmental document to the EQB. According to the EQB regulation governing the process for
the presentation and evaluation of environmental documents, when a federal agency has complied
with NEPA, then the agency will not have to present another EA before the EQB, if the local
agencies with jurisdiction are consulted during the process of the EA approval under NEPA (Rule
241. B of the EQB regulation).
Once compliance with the National Environmental Policy Act is attained, by means of the
environmental document approval, several endorsements, permits and certifications must be
obtained. These permits and certifications include:
Puerto Rico
•
•
•
•
Coastal Zone Management Program Federal Consistency Certificate (Planning
Board),
Water Quality Certificate (EQB),
Consolidated General Permit (EQB),
Concession for the Use of Territorial Waters,
38
•
•
•
•

Submerged Lands
Maritime Zone (DNER),
Joint Permit (COE, DNER)
Endorsements from SHPO, IPRC, SAC, the Puerto Rico Ports Authority, and the
Municipality of Fajardo.
Endorsement Institute of Puerto Rican Culture
Notwithstanding that the above will have significant influence on the projects approval process in
the jurisdiction of the Virgin Islands, each project independently will be subject to applicable rules
and regulations set forth in the permitting process governed by the Department of Planning
Natural Resources and the Virgin Islands Legislature.
These approvals include:
•
Coastal Zone Management Major Land and Water Permit
•
Water Quality Certificate
•
Submerged Land Lease
INFORMATION NEEDED FOR PERMITTING
1. Bathymetric Study-Including Side scan sonar
2. Magnetometer Study
3. Benthic Assessment
a. Identification of Hard Substrate which is potential acropoid Coral Habitat (and of
nominated species)
b. Identification of Coral Reefs
c. Identification of Seagrass Bed
d. Development of Biological Assessment
e. Identification of Essential Fish Habitat
f. Identification of Significant Species within Habitat type
g. Identification of Potential Impacts and Mitigation Measures
h. Development of Monitoring Plans
4.
Identification of all Existing Cables
a. Identify Owner
b. Active or Inactive
5. Identification of Potential Hazards
a. Naval Areas – unexploded ordinances
b. Sunken Vessels – Modern/Historical
c. Designated Fishing Zones
d. Restricted Zones
e. Dumping Zones
6. Archeological Investigation
a. Submarine along marine route
b. Inland along trenching routes
39
7. Turtle Monitoring
a. Prior to Installation
b. During Cable Lay
8. Manatee Monitoring
a. Prior to Installation
b. During Cable Lay
9. Survey of Landing Sites
40
REFERENCES
Acatel Submarine Networks, 1998. MAC Submarine Fibre-Optic Cable System, Segment
3, St. Croix – Bermuda, North-UP Sheet 01.
Bioimpact, 2009, Total Daily Maximum Load study conducted under contract to Cadmus
Group, Inc. for the Environmental Protection Agency, East End St. Croix
Bioimpact, 1999, Environmental Assessment Report for te Construction of the Global
Crossing Terminal Station Estate Northside, St. Croix, U.S. Virgin Islands. Submitted to
the Division of Coastal Zone Management, Department of Planning and Natural
Resources.
Bowden, M.J. et. al., 1969. Climate, water balance and climatic change in the north-west
Virgin Islands. Caribbean Research Institute, CVI,, St. Thomas, Virgin Islands.
Donnelly,T. 1966. Geology of St. Thomas and St. John, U.S. Virgin Islands. In: Hess, H.
(ed.) Caribbean geological investigations. Geol Soc. Amer. Mem. 98:85-176.
Donnelly, T., et al. 1971. Chemical evolution of the igneous rocks of the Eastern West
Indies. In: Donnely, t. (ed.) Caribbean geophysical, tectonic and petrologic studies. Geol.
Soc. Amer. Mem. 130:181-224.
Hays,W.W. 1984. Evaluation of the earthquake-shaking hazard in Puerto Rico and the
Virgin Islands. Paper present at the earthquake hazards in the Virgin Islands Region
Workshop, St. Thomas, April 9-10, 1984.
Island Resources Foundation. 1977. Marine environments of the Virgin Islands.
Technical Supplement No.1 1976. Prepared for the Virgin Islands Planning Office.
Meyerhoff, Howard A. “Physiography of the Virgin Islands, Culebra and Vieques.”
Scientific Survey of Puerto Rico and Virgin Islands, (New York Academy of
Sciences), Vol. IV, Pt. I, pp. 71-141.
Multer, H.G. and L.C. Gerhard (ed.) 1980. Guidebook to the geology and ecology of
some marine and terrestrial environments, St. Croix, U.S. Virgin Islands, Spec. Publ. No.
5 West Indies Laboratory.
TYCO Submarine Systems, Ltd, 1998, PAC Cable Network System, DeskTop Study
Charts, Grover Beach, California to Butler Bay, St Croix, Chart 19.
TYCO Submarine Systems, Ltd., 1999, Americas II Cable System, St. Croix Cable
Installation Segments A, B, and C. Method of Procedures.
41
Whetten, J.T. Field Guide to the Geology of St. Croix, U.S. Virgin Islands,” In: Multer, G.
and L.C. Gerhard (editors), Geology - Ecology of St. Croix, U.S.V.I. Special Publication
No. 5, West Indies Laboratory, Fairleigh Dickenson University, U.S.V.I. 1974.
42
APPENDIX A
APPENDIX B
List of Latest Charts and obstructions
http://www.charts.noaa.gov/OnLineViewer/AtlanticCoastViewerTable.shtml
APPENDIX C
APPENDIX D