Recommendation for Reef Ball Submerged Breakwater
with Beach, Safety, Aesthetic and Biological Enhancement
With Partners Including:
Coastal Reef Builders, Inc.
LEE E. HARRIS, Ph.D.,
Recommendation for Reef Ball
with Beach, Safety, Aesthetic and Biological Enhancement
Jan. 2001 photo of collapsed breakwater section near end of groin.3
SAJO contacted the Reef Ball Development Group, Ltd. to provide an assessment of possible ways to correct these problems in an aesthetically pleasing, functional and biologically safe way. Due to the uniqueness of the site, Reef Ball Development Group, Ltd. recommended that SAJO contact a renown world expert on submerged breakwaters, Dr. Lee Harris of the Florida Institute of Technology, to get an objective 2nd opinion of options available to address these issues. Dr. Harris and the CEO of the Reef Ball Development Group, Ltd., Todd Barber, visited the site and performed an initial assessment on April 2-3, 2001. This report is our recommendations as a result of the visit and subsequent analysis of site data.
The property is unique in its character, history, and desired use goals. Therefore, Dr. Harris, and Mr. Barber developed a unique solution that includes traditional technologies, Reef Ball submerged breakwater technologies, and a combination of known techniques by partner companies with unique, but proven skills.
We balanced the required emphasis on beauty; enhancement of the uniqueness of the property; long term stability; safety for water entry/use; reduction in wave run up, physical protection of the <<Name Protected>> during storm events; and functionality, (i.e. the creation and retention of desired beach width and slope).
As an added bonus, our approach will also create a richly diverse biological reef system that will contribute an estimated 225,000 pounds of biomass to the island of <<Name of Island Protected>> each year of which 30% will be fish life. 4
Left: 3 Years Natural Growth
Below: Reef Ball without base
The Reef Balls will provide the property with a beach 400-450 feet long (or more) with a 20 feet wide beach at high tide. The beach area will be characterized by a light lapping of waves that are attenuated by 5 rows of prefabricated Reef Balls™ 5 embedded in a custom concrete base 32 feet wide permanently attached directly to the seafloor bedrock.
The base will have a natural looking, lava like, appearance made by using free flowing concrete techniques so that even to a scuba diver, the submerged breakwater will be attractive. The Reef Balls will create a lagoon like environment in front of the property, safe for swimming and wading. The Reef Balls will allow small waves to pass to the beach retaining the sound of the beach and a true beach feel. Natural accumulation of sand will occur after the beach has been renourished as a result of the Reef Balls. This natural growth will bring a finer grain, softer sand than is on the beach today; this will contribute to a more comfortable beach. Additional options could include creation of a snorkeling area, spectacular underwater lighting effects, coral re-planting on the submerged breakwater, and further extension of the area to protect the entire length of the property. Your solution is designed to last for hundreds of years and can be considered a final solution to the problems facing the waterfront area of the <<Name Protected>>.
The next three pictures show the property, as it is today, the next two show our rendition of the property after treatment with the Reef Balls. The rendition shows the entire length of the property protected; the proposed project will protect only the first 425-450 feet from the groin side of the property which is the area most used by the current owners. The last picture is a full-page blow up of the rendition whereas page 4 shows before and after on one page for easier comparison.
View of current groin and rocks on beach from breakwater destruction by storm. [Photos by RBDG, April 2000]
After Reef Balls, Photo Rendition by RBDG, Ltd [Photo © 2001, Todd Barber
Due to the uniqueness of the <<Name Protected>>, we believe that aesthetics is one of the most important engineering requirements. The Reef Balls are symmetrical domes that would only be exposed during low tides about 6 inches above the waterline. (The tops do not have to be exposed during the low tides, but a great deal of protect from waves would be lost and therefore our recommendation is for a minimum of 6 inches of exposure at low tide).
Ultra Reef Balls being deployed at Gran Dominicas Hotel in the Dominican Republic, note the appearance of the Reef Ball submerged breakwater as only a dark line in the water. This would be the same look generated at the <<Name Protected>> at all but the lowest tides when 6 inches of the tops of the Reef Balls would be exposed.5
The Reef Balls could be internally lighted during evening low tides (or even when submerged) for a spectacular effect if desired. If the tops of dome shaped Reef Balls are exposed during the low tides for greater protection, they will match the domed architecture of the <<Name Protected>> and will be visually complementary rather than distracting like traditional rock breakwaters. One of the choices that must be made is the degree of protection desired; the client must make a final determination of the height exposed at low tide since the appearance of the breakwater is an important component of the property’s visual architectural style.
Physically, the site experiences a significant wave climate and <<Name of Island Protected>> faces threats from hurricanes.6 Although Reef Balls can be engineered heavier, with anchoring systems, and/or with modular bases for extra weight, we conclude that the use of a locally poured footer, directly attaching the Reef Balls to the ocean floor has significant advantages.
A directly adhered base has virtually no chance of being disrupted by waves. Physical adherence to the seafloor by casting the pad around the existing hard bottom adds incredible resistance to waves not obtainable by any other method. Additionally, compared to the cost of the anchoring systems and extra base weight, it is comparable in cost. We had to consider that casting on site would be disruptive to the property, but this is overcome by the use of a mini-concrete plant and concrete pump(s) installed on the barges. Therefore, on-land resources will not be required. After all of our analysis, the overriding reason to choose the poured base approach is that with the irregular bottom at the site, this is the only method that can insure all the Reef Balls are at an exact height to the water line. We felt this is a critical component to the visual appearance and function of the breakwater. An exact elevation allows minimal exposure during low tide events with maximum reduction in wave energy.
We realized that there were other advantages to the poured base. The task of removing debris rocks in the site would have been sizable, but by pouring a pad we actually take advantage of these rocks to displace concrete and create monetary savings. Additional rocks that are currently polluting the site will be incorporated into the bases to save concrete and eliminate disposal costs. There is also a significant savings in concrete since the Reef Balls can be made to weigh 4000 pounds each instead of the 6000-pound units typically used in submerged breakwater projects. The height of the poured base only needs to be high enough to level the Reef Balls to the appropriate height; extra concrete was not needed for stability of the units in storm events. And finally, this approach allows us to choose the exact layout of the Reef Balls rather than having to work around the bottom structures that might have given the submerged breakwater an uneven look.
Reef Ball has a long history of using high tech concrete to engineer structures designed to last centuries rather than decades. Our work has required it because longevity is an important design criterion when building coral reefs that potentially last for thousands of years. By using specially designed, high strength concrete and using W.R. Grace admixtures, we will create a high strength, abrasion resistant concrete, (without iron rebar in the modules), that will have an engineering life of hundreds of years. Therefore, the client can consider this solution a final one. Appendix A contains the typical concrete mix design used to build our modules. We will use a similar custom mix for the bases.
There are three options to obtaining the beach sand; sand nourishment, natural accumulation of sand, or a hybrid approach of seeding some while accumulating the rest.
Environmentally, a natural accumulation of sand is desired and Reef Ball submerged breakwaters are normally set up with this system.
Right: Natural accumulation of sand in the Reef Ball Dominican Republic Beach Creation Project after 4 months.5
However, there are not optimal sand reserves in the nearby sand sources. Even if possible, the client desires a more immediate beach solution. Because of a sizable daily wave climate, the sand found on the beach is a relatively large grain size. The sand reserves offshore are much finer. Too fine of sand is easily moved by storms but the large grain sizes are not as comfortable as a beach. Ideally, we believe a medium sand grain should be added to create a beach that would be stable in the new calmer wave climate generated by the Reef Balls, yet nicer for the beach users.
Fine sand reserves do exist in the area, but the complex shelf system does not distribute these sands evenly, especially over time. Previous reports concluded that two or more sand reserves are supplying the sand to Plantain Bay,7 The report also indicates that sand building events are dependent on a complex wave climate which are not predictable nor stable. Nonetheless, it is likely that this fine sand will work its way into the new beach from time to time as a result of the natural buildup of sand from the Reef Balls. On the good side, the beach would be even more luxurious for the feet, however fine sand might also pose an additional cleaning burden on the staff as winds may carry this onto the property.
Our understanding is that the ideal beach for the client would be 20 feet of sand at high tide with a gentle slope providing comfortable beach activities. We conclude that the best way to accomplish this is a renourished beach using medium grained sand with the submerged breakwater protecting it from loss during storm and tidal events. Finer sand would then build up over time as a top layer and be regulated in volume by the sand gate (see next paragraph) installed near the end of the groin.
This is the basis for our recommendation to conduct a hybrid sand renourishment and natural replenishment project rather than relying solely on the natural build up of sand over time.
Because the Reef Balls will still foster the natural build up of sand, a special gate has been proposed that will allow for the release of some of the sand from the beach should the beach become too large and take up too much of the swimming area. This gate will also be used to “vent off” the finer sand allowing the medium grained sand to stay if blowing sand becomes a nuisance. The recommended sand renourishment process will allow the placement of sand to the desired
1 month after a category III direct hit from Hurricane
Georges showing natural replenishment by Reef Balls.
specification (slope and width) of the client’s ideal beach. Additional sand losses from storms would be offset by the accumulation properties of the Reef Balls configured as a submerged breakwater. Therefore, a goal of the submerged breakwater is to make a protected lagoon environment in front of the property with enough wave action to augment sand reserves but not so much as to strip away the renourished sands.
Note: For this site, we recommend bringing in sand from another source rather than attempts at pumping. Being an island with no rivers and limited biogenous sand available, this is the only reasonable alternative. Purchasing sand also gives us the opportunity to select the grain size and color desired.
This project has a few activities that will impact the surrounding reef. The building of the bases will destroy the rock habitat below the breakwater, however the Reef Balls placed on this area will, over time, provide more habitat than is being lost. If pumping is used, the beach renourishment process will create some siltation and therefore silt guards should be used. (Placement of sand by land-based trucks is therefore preferred but possibly cost prohibitive). To offset this collateral damage, we recommend that a community mitigation project be undertaken. <<Name of Island Protected>> Water Sports, a <<Name of Island Protected>> Company venture, has already conducted a Reef Ball project about 450 yards away from the <<Name Protected>> in 30 feet of water where tank grown corals were transplanted onto 30 Reef Balls by Applied Marine Technologies.
The next 2 photos are of Reef Balls in <<Name of Island Protected>> about 450 yards from the <<Name Protected>> Property in 30 feet of water and transplanted with corals.
(See Photo on page 6 for location of Reef Balls deployed in November of 2000)
<<Name of Island Protected>> Water Sports staff has expressed an interest in adding more Reef Balls to this site and to obtain training from the Reef Ball Foundation on how to transplant local corals rather than purchasing tank grown corals. Since the added cost for this is so low, we recommend that the <<Name Protected>> donate 30 or more transplant ready Reef Balls and two days of coral transplant training to <<Name of Island Protected>> Water Sports.
The <<Name of Island Protected>> pictures were taken during the installation of corals in November 2000 by <<Name of Island Protected>> Water Sports.
Over a 3-year period, these Reef Balls will turn into a natural coral reef.
Photos Courtesy of <<Name of Island Protected>> Water Sports
Right: A small sized Reef Ball
(3 feet x 2 feet). This Bay Ball sized Reef Ball was deployed in Cancun, Mexico. This picture was taken 3 years later and shows only natural growth (no coral transplants were added to this Reef Ball).
The Reef Balls in <<Name of Island Protected>> will look similar to this photograph with much larger corals in 3 years. The smaller size Reef Balls could be added to the lagoon to make a snorkeling trail.
[Note: It would also be a relatively small add on project if the client desires that the Reef Balls used to create the submerged breakwater have built in coral transplant receptors so that corals could be transplanted now, or in the future on the submerged breakwater.]
Another environmental issue is the sedimentation and salinity changes created by the run off of the outfall pipes on the property. They have disrupted the life within the bay adjacent to the beach. Extending the larger pipe to the outside of the breakwater will reduce the impacts on the marine life within the protected lagoon but will move this problem to the near shore coral reefs.8 The second smaller discharge near the wading pool also contributes to the sediment in the lagoon. Installation of sediment traps and piping both offshore was recommended in prior reports as an environmental approach to the project. However, a sediment trap on the larger line near the groin is likely impractical due to the high volumes of water ejected during storms. Further mitigation may be the only option. Even without traps, impact can be reduced by discharging as close to the surface of the water as possible and not directed down toward the reef so that the fresh water is diluted sufficiently with the salt water to avoid salinity issues with the coral reefs on the bottom. Both of these pipes contribute to the sand erosion problem when they are flowing heavily and therefore redirection into deeper water is recommended at a minimum.
We believe the small costs associated with addressing these issues and the associated mitigation project(s) will help insure the work done at the <<Name Protected>> follows the philosophy of good stewardship that is part of the <<Name of Island Protected>> island culture.
Reef Balls were initially designed to be biologically active and to be stable in hurricanes. Essentially Reef Balls needed to be the base of a natural reef. To do this, we had to design our holes to create whirlpools so that corals could be fed better by passing currents. Additionally, we created a large hole in the top of the Reef Ball so that waves and currents would be jetted from the top, adding to the stability of Reef Balls. Our goal was to use the least amount of concrete to make a unit that was stable in hurricanes.
Traditional and barrier submerged breakwaters work by making waves break. As a wave breaks, it loses much of its energy. The problem with these systems is that if the wave does not break, very little energy is lost. And as the wave is lifted over the submerged breakwater, if it does not break, then the acceleration, as it goes down on the other side of the breakwater, can create washout.
Reef Balls work on an additional principle. Being full of holes that create whirlpools, and
offering a variety of angles of reflection from the round shape, any wave that
traverses a field of Reef Balls has to “fight itself” and therefore looses energy
in relation to the number of
Wind tunnel demonstrating whirlpool effect of Reef Balls
rows of Reef Balls that are traversed. The original wave keeps its shape; it just gets smaller and continues to the beach without washout. Therefore, it does its normal job of carrying sand, at the lower energy level, to the beach.
With major storm events, the width of the Reef Ball fields must be wide enough to cause a break on the larger waves like a traditional submerged breakwater. This slows them by the Reef Ball Stability Tests at FIT Wave Tanks
normal breaking process and also by fighting the whirlpools/wave reflections as with non-breaking waves. In these major storm events, wash out is possible even with the Reef Balls because the breaking waves always create wash.
(Note: Since the seafloor on the lee side of the proposed position of the Reef Ball is rock or limestone outcroppings, wash out is not an issue for the proposed solution.)
Traditional solid submerged breakwaters may perform better than Reef Balls for natural sand accumulation if the wave climate is very light. This is because Reef Balls will slow down even smaller waves and if there is normally barely enough energy to bring sand to the beach, the Reef Balls may slow the waves too much and cause sand to fall out just past the Reef Balls, rather than on the beach. If average waves are very small and storms also bring proportionately small waves, consider either placing your Reef Balls closer to shore or use a solid submerged breakwater if using a system designed to naturally create sand. If you are renourishing your sand, it is always better to have a lower wave climate so Reef Balls are the best choice. This is because you don’t want waves to carry away renourished sand. At the <<Name Protected>>, the wave climate is anything but small and the recommend solution includes renourishment and this is not a consideration to be worried about.
Non-submerged structures that stick out of the water rely on reflection to stop waves. Reflection puts a huge stress on walls and that is why most reflective structures must be massively engineered and even then failure is possible. Non-submerged structures are also unappealing to the eye in most installations. This reflection effect can also push sand away from the property. This is why the current seawall has accelerated the rate of sand loss on the property. To solve this problem, the renourishment should fill sand significantly up the seawall. Reflection of waves has been blamed on a variety of problems (both physical and environmental) with traditional engineering techniques and therefore Reef Ball Development Group, Ltd. does not recommend reflective technologies.
Safety is another issue for the client. Children and other potential waders/swimmers are present on the property and the dangerous undertow at the site today could create a tragedy. The submerged breakwater is designed to reduce the energy of the waves to make swimming and wading safe. Reef Balls may also provide a physical barrier to reduce the loss of a swimmer to sea. A field of five rows of Reef Balls will provide many opportunities for a swimmer to hold on for rescue before being swept into the sea. However, coral growth and waves breaking on the Reef Ball could still cause injury and therefore only experienced swimmers should intentionally be among the Reef Balls. Consider the breakwater as a last “fence” to the sea, but not a boundary for safe swimming. Safe swimming should only be practiced within the calmer waters of the lagoon created by the submerged breakwater.
Protection from wave run up and damage to the <<Name Protected>> during hurricane or tropical storm events was a goal of previous projects. Because of the low elevation of the house and upland property itself, we cannot claim any hurricane protection! However, if both the submerged breakwater and the beach system are functioning there will be a reduction in wave run-up. More exposure of the Reef Balls at low tide would allow the system to function longer if sea levels rise during storm events.
There will be a variety of companies participating in this project working through the Reef Ball Development Group, Ltd. and contracted through ASJO. ASJO may at its discretion either contract individually with these companies or work through Reef Ball Development Group, Ltd. to manage the construction as a single project. Because of the unique nature of doing business in <<Name of Island Protected>>, it is expected that ASJO & Reef Ball Development Group, Ltd. will work closely as partners to bring the project to a successful completion.
Todd Barber, CEO of the Reef Ball Development Group, will personally oversee this project due to its unique and complex nature. Mr. Barber is the founder of Reef Ball Development Group, Ltd. and has been working restoring reef systems worldwide since 1992. His work in the management-consulting field with the Alexander Group and TPF&C before starting Reef Ball makes him well qualified to manage complex projects. Reef Ball has conducted over 3000 projects in over 40 countries worldwide deploying over ½ a million Reef Balls. Information on the companies Mr. Barber manages can be found at www.artificialreefs.org.
Dr. Lee Harris, Ph.D., P.E., Consulting Coastal, Ocean and Civil Engineer of the Florida Institute of Technology will be doing the engineering, physical modeling, survey work and scientific monitoring of the project. He has worked with submerged breakwaters since the 1980s and has been involved with hundreds of projects worldwide.
Coastal Reef Builders, Inc.
Coastal Reef Builders, Inc. is a Pensacola, Florida based marine contractor with barges, tugs, cranes, and all the equipment that will be required to conduct the in water construction at the <<Name Protected>>. Coastal Reef Builders, Inc. has been a Reef Ball Authorized Contractor since 1993 and they have completed over 20 large-scale projects for the Reef Ball Group. They are licensed and insured and have a great deal of experience with the Ultra Ball sized Reef Ball that is our largest size and has been selected for your breakwater. Dale Minnick will be your barge Captain and the barge owner Bill Carson will also assist the barge crews. They will use a combination of their own equipment and equipment leased or purchased in the Caribbean to minimize barge and deployment cost which are the largest expenses in this project.
Reef Innovations is the largest builder of Reef Balls in the U.S. having built and deployed more than 50,000 Reef Balls. The company has divers on staff that will help with in water operations as well as the construction of your Reef Balls. Reef Innovations has been an Authorized Contractor for Reef Ball Development Group, Ltd. since 1995. The company President Larry Beggs and his production manager Harry Rolfe will be assisting us with your project. They bring a great deal of experience and skill sets to the project.
CEMEX US (D.B.A. Southdown Concrete) will allow a special leave of absence for an employee, Mike Burhans, that has worked with Reef Balls internally for several years to oversee and conduct the concrete mixing and dispensing from the barge directly into specialized molds to create bases for your Reef Balls adhered to the ocean floor. Southdown and W.R. Grace are working together to design a custom concrete mix for your site that meets Reef Ball Development Group’s tough standards for longevity and biological compatibility.
W.R. Grace will supply critical admixtures including Force 10,000 Microsilica, Adva Flow, Grace Microfibers, Darex II and other proprietary admixtures used to insure that your Reef Balls and breakwater will last for hundreds of years and will be strong enough and abrasion resistant to handle the constant sandblasting effect subjected to a submerged breakwater. We have elected to engineer your breakwater with the some of the best concrete technology available today that is also designed to enhance the biological performance of your breakwater as a living reef. Rick Conlin is in upper management at W.R. Grace and will be our liaison with W.R. Grace. He has worked designing special mixes for the Reef Ball Group since 1993.
The Reef Ball Foundation is a 501(c) non-profit charitable organization. Its mission is to help restore our world's ocean ecosystems and to emphasize and protect our natural reef systems through preservation, technology, and innovative public education opportunities, and community involvement. The Foundation works with governments, businesses, schools, research institutes, and community organizations. Kathy Kirbo is the Executive Director of the Foundation and she will assist with the Reef Ball donation to <<Name of Island Protected>> Water Sports, if you elect this option. If you wish to qualify as a Reefs Around the World project, then your expenditures could be a tax write off as a donation to a US based charitable organization.
Qualification would entail a coral transplant program on your breakwater, mitigation of any reef damaged by the project, best efforts to reduce the damages from the outfall drainages and 2 monitoring visits per year for 3 years. If a US based tax write off is important to the client, further discussions with the Reef Ball Foundation are warranted.
There are several steps that must be undertaken in a rapid fashion to meet the window of barge availability and acceptable weather risks in the Caribbean. As such, time is of the essence if you wish to complete this project in 2001. In order to proceed with the development of a detailed project timeline and exact budget, five important first steps must be completed:
· Completion of a scale model
· Site survey of barge equipment (required if equipment is being rented near island)
· Completion of a project kick off meeting with all parties attending
· Refinement of the budget spreadsheet model
· Authorization from client to proceed with project
Some “quick and dirty” in water modeling work has already been accomplished, at our expense, to conclude that five rows was the appropriate width of the breakwater so that our initial costing would be “in the ballpark”.
Model showing wave attenuation properties of 4 rows of Reef Balls.
However, due to the unique nature of this project, we suggest a complete scale model including the poured base and height leveling to tide with generated scale waves. The purpose of this is several fold. Dr. Harris will be able to validate that 5 rows with 6 inches at low tide are required to attenuate the waves to the desired levels. Dr. Harris can also tell us, at this time, if any design modifications might be necessary. If changes from our initial assumptions are required, this could have an impact on costs and our planning of appropriate barge sizes, etc. Secondly, the modeling may reveal simplifica-tions or cost savings to the actual construction of the Pour In Base™ molds, and other projects that may be asked of us such as the installation of the drain pipe, lighting systems, etc. Finally, the scale model will be filmed so that the client can visualize the wave climate at the <<Name Protected>> after protection.
Model with generated waves showing attenuation.
Once you approve the more extensive modeling and the initial, unrefined, budget, then the next step is to have a kick-off meeting where all the sub-contractors and the client(s) get together to discuss the actual methodology of each sub-project, timing and final costing. It is likely that the barge contractor (Coastal Reef Builders, Inc.) would also need to do a barge survey trip to survey potential equipment that might be obtained locally before final costs could be determined. Coastal Reef Builders has been in touch with some marine operators in Bequia that may be providing some of the marine equipment needed. SAJO has provided us with a contact for Phoenix Marine Co. Ltd. that may also provide needed equipment.
Observations on the “quick and dirty” modeling.
· When we made the maximum size waves we could, it was possible to generate a small reflection wave off the seawall when less than 5 rows of Reef Balls were used. 3-4 rows were sufficient to protect the beach when the Reef Balls were at or above the surface of the water. 2 rows or less did not provide adequate protection and we were able to generate beach movement. (Note: Our “quick and dirty” model did not have a poured base, nor Reef Balls that were all at the same height. The outmost balls were at a lower elevation due to the slope of the beach. Therefore, we expect the leveled Reef Balls to perform better than this modeling exercise)
· When waves were generated at just the right angle, it was possible to erode some sand (about 30 feet by scale) from the end of the Reef Balls that did not have a groin. This might suggest that the submerged breakwater needs to be a little longer than the area of the beach it is intended to protect. However, the shape of the island of <<Name of Island Protected>> provides good protection on that side of the property and this protection was not included in our initial model. (See photo on page 6)
· The Reef Balls lost almost all of their ability to attenuate waves when they were, to scale, 4-5 feet below the surface of the water. Given a 1.5 foot tide range and the Reef Balls placed at .5 feet above mean low water, a 3 foot surge occurring with a hurricane event during a high tide could submerge the Reef Balls by 4 feet. This means that the Reef Balls might not provide protection against wave run up. This emphasizes the need to balance the aesthetics of exposure during low water verses wave run up protection during major storm events.
· After 5 days in the water with regular waves plus a twice-daily generation of maximum waves, our model beach is still perfectly intact and shows no signs of erosion.
(Note: Model left for 5 days only had 4 rows of Reef Balls).
After the pre-proposal work is concluded, a final proposal with an accurate project budget and project timeline can then be developed. Upon receiving authorization to proceed and obtaining the appropriate retainers, the project could then commence full scale. We cannot over-emphasize the importance of moving quickly on the project unless a delay until 2002 is acceptable.
We have developed an internal spreadsheet model to help us better estimate the cost involved in your project Currently, our model has not been refined by the pre-proposal work, but to help set expectations we currently believe the total project would cost roughly US $1,500,000 including most options (such as a sand control gate, 5 rows, 450 feet of breakwater, 30 Ultra Balls and training donated to <<Name of Island Protected>> Water Sports, estimated sand at $22/ton, sand placement, and most other aspects of the project).
Our style is to work with you on a line item basis to review the spreadsheet model and develop the exact project that fits your budget and expectations. Although it would be possible for us to provide you with a higher “turnkey” price, we believe that working together to minimize costs would be the best approach given the uniqueness of island work.
With your current authorization, we will begin only the pre-proposal work and begin billing you by our normal consulting terms.
We ask for a deposit of 1/3rd of anticipated fees and expenses in advance that are credited to your final payment, and you will be billed monthly for actual expenses and fees. The anticipated expenses and fees budget for the modeling, barge survey and the kick off meeting are $20,000 (presuming the kick off meeting is held in Sarasota, travel and expenses are not budgeted for SAJO or other client representatives).
APPENDIX A: REEF BALL TYPICAL CONCRETE SPECIFICATIONS
PART I - GENERAL
1.01 Section Includes
A. Concrete proportioning and products to be used to secure concrete, which when hardened will produce a required strength, permeability, and resistance to weathering in a reef environment.
A. ACI-211.191-Standard Practice
for Selecting Proportions for Normal, Heavyweight, and Mass Concrete.
B. ASTM C 260- Standard Specifications for Air-Entraining Admixtures for Concrete.
C. ASTM-C 1116 Type III- Standard Specifications for Fiber Reinforced Concrete or Shotcrete.
D. ACI - 305R -91- Hot Weather Concreting.
E. ACI - 306R -88- Cold Weather Concreting.
F. ACI - 308- Standard Practice for Curing Concrete.
G. ASTM C 618-Fly Ash For Use As A Mineral Admixture in Portland Cement Concrete.
H. ASTM C 494-92- Standard Specifications for Chemical Admixtures for Concrete.
I. ASTM C 1202-91- Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration.
J. ASTM C 33- Concrete Aggregates.
K. ASTM C 94- Ready Mix Concrete.
L. ASTM C 150-Portland Cement.
M. ACI 304- Recommended Practice For Measuring, Mixing, Transporting and Placing concrete.
N. ASTM C 39 (Standard Specifications For Compressive Testing)
O. ASTM C-1240-93 (Standard Specifications for Silica Fume Concrete)
PART II PRODUCTS
2.01 Portland Cement: Shall be Type II and conform to ASTM C-150
2.02 Fly Ash: Shall meet requirements of ASTM C-618, Type F. And must be proven to be non-toxic as defined by the Army Corps of Engineers General Artificial Reef Permits. Fly Ash is not permitted in the State of Georgia and in most Atlantic States. (In October, 1991, The Atlantic States Marine Fisheries Commission adopted a resolution that opposes the use of fly ash in artificial reefs other than for experimental applications until the Army Corps of Engineers develop and adopt guidelines and standards for use.)
2.03 Water: Shall be potable and free from deleterious substances and shall not contain more that 1000 parts per million of chlorides or sulfates and shall not contain more than 5 parts per million of lead, copper or zinc salts and shall not contain more than 10 parts per million of phosphates.
2.04 Fine Aggregate: Shall be in compliance with ASTM C-33.
2.05 Coarse Aggregate: Shall be in compliance with ASTM C-33 #8 (pea gravel). (Up to 1 inch aggregate can be substituted with permission from the mold user.) Limestone aggregate is preferred if the finished modules are to be used in tropical waters.
2.06 Concrete Admixtures: Shall be in compliance with ASTM C-494.
2.07 Required Additives: The following additives shall be used in all concrete mix designs when producing the Reef Ball Development Group's product line:
A. High Range Water Reducer: Shall be Adva Flow as manf. by W.R. Grace.(ASTM C-494 Type F)
B. Silica Fume: Shall be Force 10,000 Densified in Concrete Ready Bags as manf. by W.R. Grace. (ASTM C-1240-93)
C. Air-Entrainer: Shall be Darex II as manf. by W.R. Grace (ASTM C-260)
2.08 Optional Additives: The following additives may be used in concrete mix designs when producing Reef Ball Development's product line.
A. Fibers. Shall be either Microfibers as manf. by W.R. Grace, or Fibermesh Fibers (1 1/2 inches or longer) as manf. by Fibermesh. Either product can be in ready bags.
B. Accelerators: Either a non-Chloride or Daracell as manf. by W.R. Grace may be used but only when needed due to temperatures less than 40 degrees F. (ASTM C-494 Type C or E)
C. Retarders: Shall be in compliance with ASTM-C-494-Type D as in Daratard 17 manf. by W.R. Grace
2.09 Prohibited Admixtures: All other admixtures are prohibited. Other admixtures can be submitted for approval by the Reef Ball Development Group, Ltd. by sending enough sample to produce five yards of concrete, the current MSDS, and chemical composition (which will be kept confidential by RBDG Ltd.) A testing fee of $2,500 must accompany the sample. Temporary approval will be granted or denied within 10 days based on chemical composition, but final approval may take up to 3 months since samples must be introduced in a controlled aquarium environment to assess impacts on marine and freshwater species.
PART III Concrete Proportioning:
A. General: The intent of the following proportions is to secure concrete of homogeneous structure that will have required strength and resistance to weathering.
Left out as proprietary
*Adva Flow (Superplastisizer):
*NOTE: Adjust Adva dosage as needed to obtain workable, placeable mix (170-250mm / 7-10 inch slump), and to achieve .40 w/c ratio.
Fibers: 0-3# (Max.) as needed to reduce micro cracking 1# (Min.) required if Silica Fume exceeds 50#
Accelerator: As needed to achieve de-molding no sooner than: 3-4 hours for heavy duty molds (All Polyform side balls) 6-7 hours for standard molds (Molds with any tether balls)
NOTE: Silica Fume or Force 10K shall be dosed at a 10# minimum in Bay Balls and Pallet Balls while Ultra & Reef Balls shall require a minimum of 25#. All molds must use at least 50# for floating deployments. All mold sizes must use at least 50# for use in tropical waters unless special curing procedures are followed.
* This product is being specified not only for strength, but also to reduce pH to spur coral growth, to reduce calcium hydroxide, and to increase sulfate resistance. It is a non-toxic pozzalan.
Appendix B: Report from Dr. Lee Harris, Ph.D., P.E.
Consulting Coastal/Ocean/Civil Engineer
Reference site visit with Todd Barber and Carl Field on 2-3 April 2001 and report on “Shoreline Protection and Enhancement of the <<Name Protected>>, Plantain Bay, <<Name of Island Protected>>” by Smith Warner International Ltd. provided on 5 April 2001.
Although the bathymetric survey data shown in Figure 4.1 of the report was reduced to such a small scale as to be unreadable, making it impossible to determine precise project location and design details, the site visit and report do provide sufficient information to develop and confirm the general design concepts. Construction cost estimates can be made using the number of rows of units and breakwater heights as variables, pending further fieldwork and/or data provision and the model study.
The report cites "..approximately 10 beach profile lines" that were surveyed, and it does look like they are shown on the plan drawing of Figure 4.1. However, to use that data to the fullest, the plotted cross-sections of the beach profile data are needed, which is not included in the report. The profile lines need to have their location indicated, and show the seawall location and elevation. Figure 6.1 seems to have the beach profile shown plotted as "depth" but this may be a composite profile line rather than an actual one. Figure 7.5 shows the beach fill, but only on a generic rather than using the actual profile line data. Actual survey data could be used to more accurately determine the volume of sand fill required, as well as to more fully assess the position and design details of our Reef Ball reef breakwater.
Tide data in the report gives a small tide range of 0.4m = 1.3 feet tide range, making the use of submerged breakwaters applicable to this site. The tide datum is LAT (lowest astronomical tide) so the lowest possible water level due to astronomical tides is LAT = 0.0m; lowest normal water level is MLLW = 0.1m LAT; highest normal water level is MHHW = 0.5m LAT; and then storm surges, wave set-up and run-up create higher water levels during storms or large wave events. There are no data on currents in the report.
From the site visit it is clear that there are two primary beach erosion problems, one that is constantly occurring and the second that is episodic:
Previous coastal construction of the existing groin and offshore-segmented breakwaters have exacerbated the first problem, by channeling and increasing the current flow between the seaward end of the groin and the nearby breakwater. This problem can be addressed by modifying the coastal structures, as described in the recommended design.
The drain outlet should be relocated so that it does not wash the sand off the beach. This can be done through the existing groin, as recommended in the cited report, or extended further offshore than the seaward end of the existing groin.
Our recommended design is one continuous line connecting to the existing groin and extending 400 to 500 feet to the north, without the gaps between the breakwaters, thereby preventing the high current flows between the segmented units (especially from between the seaward end of the groin and the adjacent breakwater, with an optional "gate" to allow sand release in future if needed). If the same 1.5 to 2.0 meter water depths (5 to 6.6 feet depths) as the cited report recommends are used, the breakwater reef can have a base height of 1 to 2.6 feet so with 0.5 feet Reef Ball unit embedment and 4.5 feet high RB units, the top height will be up to the water surface. Moving the structure closer to the
shore and into slightly shallower depths would afford more protection and lower the structure height and quantity of concrete required, which will be investigated with better bathymetric data and the proposed model study.
If we have our design the same widths as the report (30 to 36 feet) it would be 5 to 6 units wide using 6' wide bases. Based on model studies, we may be able to reduce this width to 4 units wide, but price difference may not be that substantial. A rock groin on the north end of the property can be included for future addition to the project if needed, but not recommended for initial project construction.
The recommended design will include beach fill to restore the beach to the desired width for recreational use and upland protection. The design beach fill profile will be developed from surveyed profile lines, so that the elevations and quantity of sand required can be determined.
The recommended design and Reef Ball breakwater will stabilize the beach in the following ways:
Reef Ball breakwater will be cemented to the bottom, providing an extremely stable structure
3 Photo sent by Daniel Polegato of SAJO.
4 Japanese studies [Japanese Artificial Reef Technology, Translations of Selected Japanese Literature and An Evaluation of Potential Applications in the U.S. Technical Report 604, Aquabio, Inc. 1982] have indicated that 4 feet cube blocks with holes create about 400 lbs of biomass per year. Ultra Reef Balls are 6 feet by 4 feet and with greater complexity than scientific control blocks. Therefore it is assumed that the 600 lbs per year biomass expectation is conservative. Artificial reefs have different productive rates in different ecosystems and therefore these are only approximate estimates.
5Reef Ball, Ultra Ball, Pallet Ball, Bay Ball, Lo Pro Ball, Oyster Ball, Reef Cube, Pour In Base, and some other terms are Trade Marked by the Reef Ball Development Group, Ltd. See www.reefball.com/reef.htm for additional trademark and patent information.
6 Photo by RBDG, Ltd. Submerged breakwater is only 3 rows wide, the recommended solution for the <<Name Protected>> is 5 rows wide so the dark band would appear wider.
8 “Shoreline Protection of and Enhancement of The <<Name Protected>>”, June 1996, by Smith Warner International, Ltd.
9 Ibid. The report confirms the existence of nice coral reef patches on the outside of the proposed submerged breakwater.
Table of Contents
Executive Summary 2
Purpose of this Report 3
Recommended Solution 3
Project Details 7
Aesthetics of Project 7 Stability 8
Beach Creation 9
Environmental Responsibility 10
Why Reef Balls Work Better than Solid or Rock Submerged Breakwaters 12
Safety & Property Protection 14
Participating Sub-Contractors & Partners 14
Reef Ball Development Group, Ltd. 14
Dr. Lee Harris 15
Coastal Reef Builders, Inc. 15
Reef Innovations, Inc. 16
W.R. Grace Construction Products 16
Reef Ball Foundation, Inc. 17
Preliminary Proposal 18
Observations on the “quick and dirty” modeling. 19
Appendix A: Reef Ball Concrete Mix Design 21
Appendix B: Report from Dr. Lee Harris, Ph.D., P.E. 25
Consulting Coastal/Ocean/Civil Engineer
Data Provided 25
Erosion Problems and Solutions 25
Recommended Design 26