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rag I' The Criteria Options' and [valuation

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4 Preservation Options and Evaluation Criteria THE OPTIONS The committee identified and evaluated ten principal options, some of which foreclose others. For example, relo- cation would eliminate from immediate consideration the con- struction of a seawall, and a seawall would make subsequent relocation difficult or impossible. Other options, such as beach nourishment or breakwater construction, could be used in combination. The committee did not evaluate every pos- sible option, but selected the following as worthy of consid- eration: Incremental relocation of the lighthouse intact Rehabilitation of the groinfield without revetment Rehabilitation of the groinfield with revetment Seawall/revetment Artificial- reefs Offshore breakwaters and groinfield rehabilitation Deployment of artificial seagrass Continuing beach nourishment No action New lighthouse CRITERIA TO EVALUATE PRESERVATION OPTIONS To evaluate the options, the committee developed a set of criteria or tests against which to judge the options. The 47

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48 committee then discussed appeared relevant. Each respect to each criterion. The criteria the committee used are: Criteria, Options, and Evaluation and listed those criteria that option was then discussed with Technical feasibility. Can the option be implemented suc- cessfully from a technical or engineering standpoint? Long-term reliability. Will the option protect the light- house for at least 100 years? Short-term reliability. house for at least 20 years? Initial cost. the option? Will the option protect the light What is the approximate cost to implement Long-term cost. What are the likely recurrent future costs to maintain the effectiveness of the option? Protection of natural resources. What are the potential effects on ecological, hydrological, geomorphological, and related natural systems and processes in the vicinity of Cape Hatteras Lighthouse? Aesthetic impact. What is the visual effect of the option? Local public considerations. How are residents of the Outer Banks, specifically Buxton, N.C., likely to view the option? Protection of historical values. What is the implication of the option for preserving the lighthouse, its associated build- ings, and its historical milieu? Will a precedent be set for protection of other historic structures similarly endangered? Public access and recreation. What is the effect of the option on public enjoyment of the lighthouse site, including the beach in front of it?

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Options and Criteria 49 Risk of damage to the lighthouse during implementation. What is the likelihood of damage to or destruction of the lighthouse due to or during implementation of the option? Preservation of other options--short term. To what extent does the option immediately foreclose alternative pres- ervation options? Preservation of other options--Ion" term. ervation options foreclosed after 20 years? Are other pres Construction time. How long will it take to achieve effective protection after an option is chosen? Coastal Barrier Resources Act. Although NPS is not covered by the CBRA, to what extent is the option consistent with the act? NPS shoreline-management policies. Is the option consis- tent with NPS policy not to obstruct natural processes on coastal barriers? North Carolina coastal policies. Is the option consistent with state policy on response to shoreline retreat? Flood-hazard mitigation. How does the option relate to the national goal of reducing flood hazards through adjust- ment of land use in floodplains, the National Flood Insurance Act, and Executive Order 11988? Wetlands effects. What is the option on wetlands and other U.S. Section 404 of the Federal Clean Water Act? potential effect of the waters regulated under Fisheries. What are the potential effects of the option on commercial and recreational fish habitats? Navigation. How would the option affect commercial and recreational navigation? The criteria fit into four general categories. The first contained crucial criteria: if an option failed to meet these

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50 Criteria, Options, and Evaluation criteria, it was not considered further. The crucial criteria were technical feasibility, short-term reliability, initial and long-term cost, protection of historical values, and risk of damage to the lighthouse during implementation. Options that met the criteria in category 1 then were considered against criteria in category 2. This category con- tained important criteria but not so important that failure to meet one of them automatically excluded an option from fur- ther consideration. Some of these criteria are relative-- although no option would guarantee protection under all cir- cumstances, some would offer better protection than others. All options that would provide at least some protection would cost a substantial amount of moneY. but some would cost more than others. . . . . . . - ~. ~. . . - . ~ ~ , The criteria in category 2 were long-term ready, Nag and ~ong-~erm cost, protection of natural recreation, lone term. _ resources, aesthetic impact, public access and preservation of other options in the short and construction time, and NPS shoreline-management policies and North Carolina's coastal policies. The third category consisted of criteria that overlapped with one or more in category 2: Coastal Barrier Resources Acts flood-hazard mitigation, and wetlands effects. Although these criteria were not identical to any in category 2, every time the relevant category 2 criteria--i.e., protection of natural resources and relevant coastal-management policies-- were met, these criteria also were satisfied. Category 4 contained two criteria that did not appear to be affected much by any option--fisheries and navigation-- and one criterion, local public considerations, which is impor- tant to decision makers but outside the committee's purview. Six options failed criteria in category 1. Deployment of artificial seagrass is not technically feasible in that it does not work, and the committee was uncertain of the effective- bullulng a new light- nouse would not protect historical values as required by NPS's mandate. Beach renourishment would incur excessive long-term costs, and no action or rehabilitation of the groin- field without a revetment would not provide reliable short- term protection for the lighthouse. The committee's evaluations of the remaining four options were based largely on criteria in category 2 and are dis- cussed in detail in Chapter 5. In brief, relocation would not , . . ness of artificial reefs at this site.

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Options and Criteria 51 fail any criterion. The seawall/revetment option would con- flict with coastal management policies, historic preservation, long-term cost, public access and recreation, aesthetic con- siderations, risk of damage during implementation, and pres- ervation of other options. Rehabilitation of the groinfield with a revetment and offshore breakwaters with groinfield rehabilitation would not satisfy criteria concerning long-term reliability and shoreline management policies. The types of conflicting considerations faced by the com- mittee (such as conflicting public policies and the desirability of minimizing cost while maximizing protection) also might arise in other NPS decisions regarding historic preservation and conservation. The committee suggests that an approach similar to one it used--developing a set of relevant criteria and studying options against those criteria--would prove use- ful for other decisions that involve conflicting considerations.

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5 Evaluation of the Options The committee provides cost estimates for the options discussed below (except for artificial reefs, for which too many variables are involved, and artificial seagrass, for which no effective level of application can be determined). In some cases, estimates from other sources were used as the basis for the committee's estimates. In other cases, the committee developed its own estimates. The committee's cost estimates are conservative, and should be considered as guides, within a range of perhaps +20%. The actual cost of each option can be determined only by receiving a specific proposal from a contractor. Variables not included in the committee's cost estimates include com- petition, experience, expertise and equipment already owned, and time involved in obtaining necessary permits and insur- ance. Several options imply costs of maintenance and repair or of rebuilding or choosing another option in the future. In addition, an appropriate discount rate must be applied when considering future costs. - For example, if OMB's current dis- count rate of 10h per year is applied, a cost of $5 million 30 years in the future is minor compared with a similar cost next year. Except in the case of beach nourishment, the committee did not attempt to account for inflation in future costs, and all estimates of future costs are in present dollars. In addition, the committee made no attempt to adjust pre- vious cost estimates from other sources. Thus, the dollar values of all previous estimates are valid for the dates of the estimates. 53

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54 Criteria, Options, and Evaluation INCREMENTAL RELOCATION: THE PREFERRED OPTION Overview The committee concluded that the best option is to relo- cate the lighthouse a minimal distance--400-600 feet (122- 183 meters)--to the southwest, which will ensure protection for approximately 25 years. Thereafter, the lighthouse should be moved further as advance of the sea requires. Steel lifting beams for the move would be left in place (concealed by sand) to facilitate future moves. Subsequent moves would be less expensive than the first, because much of the work required need be done only once. * The current groinfield would not be repaired under this option. Choice of the initial resting site should be made by NPS; the committee favors an area close to the southwest corner of the present parking lot. This and other areas are dis- cussed under "Site Selection." The committee recognizes that methods for relocating the lighthouse other than the rail and track method described below are available. However, based upon the information currently available to it, the committee believes this method will minimize cost and will minimize cost and ecological damage. Detailed confirmation of the correctness of this approach and the technical details of any relocation must be determined by a contractor, retained by NPS. A conceptual description of the committee's suggestion is outlined below. In preparation for the move, the building's structure would be assessed and minor repairs and reinforcements made as needed. The foundation of the lighthouse would be tun- neled for insertion of a series of needle beams. Then the lighthouse (minus part of its below-surface foundation and The three groins were constructed by the Naval Facilities Engineering Command to protect the U.S. Navy facility north of the lighthouse, although the south groin was installed south of its originally planned location to extend protection to the lighthouse (U.S. Army Corps of Engineers, 1985~. The present committee was asked to consider options to protect the lighthouse, not the Navy facility. If the groins were maintained, they would probably continue to reduce beach erosion in front of the Navy facility and the lighthouse.

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Evaluation of the Options 55 the timber mat) would be vertically raised by hydraulic jacks to clear the below-surface foundation that remained. The lighthouse would be lowered onto rollers that rest on multiple horizontal steel-rail beams supported by precast con- crete piles. The entire lighthouse structure would be moved on the tracks with hydraulic jacks and pulled to its new site , where it would be placed on a newly constructed foundation, such as a pile-supported concrete mat (Figure 9~. The total time estimated for the move, including engineering analyses, is approximately 1 year; preparation and relocation of the lighthouse would take fewer than 3 months. The actual relo- cation should not occur during hurricane seasons--summer and fall. It is expected that the light will be nonfunctional during this 3-month period. The keepers' quarters could be moved using standard housemoving techniques. Before relocation, the external structure would be strengthened and reinforced as an integral unit by vertical and circumferential prestressing as discussed in "Risks to the Lighthouse," and as shown in Figure 10. The foundation tun- neling would involve no movement of the tower. Needle beams would be inserted immediately into 3-foot (91 cm) tun- nels; thus, the base of the lighthouse would not be weakened. During lifting, hydraulic jacks would be equipped with mechanical locknuts, and cribbing would be placed close behind; this would limit vertical displacement to less than inch ( 1.3 cm) in case of jack failure. Were a jack to fail, the center of gravity would move about 11 inches (3.2 cm) horizontally. The top would move more, but such displace- ment should have little effect on the stability of the light- house. _ ~. ~. . ~- - - - - , . Cost of First Move The MTMA Associates report ( 1980) described relocation of the lighthouse in one piece to an area approximately 2,800 feet (850 meters) southwest of the present location at a cost of $2.7 million. The NPS Environmental Assessment ( 1982) estimated $5.9 million, and the Move the Lighthouse Commit- tee (Fischetti et al., 1987) estimated $3.2 million to move the lighthouse to the same area.

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90 Criteria, Options, and Evaluation Beach Nourishment Sand from nearby sources could be pumped to the beach in front of the lighthouse. Beach nourishment has been applied to eroding shorelines north of the lighthouse in amounts of 312,000 cubic yards (240,000 cubic meters) in 1966, 200,000 cubic yards (153,000 cubic meters) in 1971, and 1.25 million cubic yards (960,000 cubic meters) in 1973 (MTMA Associates, 1980; U.S. Army Corps: of Engineers, 1985~. Cost MTMA Associates ~ 1980) estimated an initial cost of $2.9 million to pump 500,000 cubic yards (380,000 cubic meters) of sand to the beach in front of the lighthouse. Supposing a need for an additional 300,000 cubic yards (230,000 cubic meters) every other year and 300,000-500,000 cubic yards after every major storm, the long-term cost was estimated at more than $120 million (not discounted) over 100 Years. NPS ~ , , (1982) estimated an initial cost of $3 million and a 50-year cost of $60 million. To nourish the beach with 1,000,000 cubic yards, the committee estimated an initial cost of approximately $2 million and further estimated that the maintenance cost--initially about $700,000 per year--would increase with time. Even applying OMB's discount rate of 10% per year, a maintenance cost of $700,000 per year over the next 20 years is worth more than $5,000,000 in present value. Evaluation Beach nourishment, achieved by transporting sand from near Cape Hatteras or from Diamond Shoals, is one techni- cally feasible response to the erosion problem at the light- house. This approach -has the merit of requiring no visually obtrusive structures at the lighthouse except those related to pumping sand. Furthermore, the sand to be taken for place- ment at the lighthouse is not needed to maintain a developed the virtually permanent . - downdrift shoreline. ~i, ~. . . Nevertheless,

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Evaluation of the Options 91 pipeline and pumping equipment necessary for the repeated nourishments would intrude upon the natural setting and interfere with beach use by visitors to the seashore. ~^ ~ ~ 11- sand were taken from the beach near Cape Hatteras, the huge borrow pits might interfere with beach access and reduce nesting sites for birds. However, the benefits of beach nourishment are short lived. Therefore, large quantities of new sand must be applied frequently to counteract erosion. The decisive criterion that this option fails is cost. The costs of beach nourishment are prohibitive, as described above, and, as the shoreline continues to retreat, the costs of maintaining an increasingly large artificial promontory at the lighthouse would grow disproportionately. Within 50 years, this option may become technically unfeasible as well as prohibitively costly. Furthermore, this option to control erosion at the lighthouse does not ensure against loss of the lighthouse during a major storm. ,, , . . No Action Although the committee was charged with evaluating options to preserve the lighthouse, it includes! no action as a management alternative, consistent with the National Envi- ronmental Policy Act. No action would lead to loss of the lighthouse within the next few decades, or possibly sooner, in the event of a direct hit by a severe hurricane or series of lesser storms. The option of doing nothing was eliminated from consid- eration because it would expose the lighthouse to a high risk of loss. The lighthouse probably would not be standing today without the present groin system. An additional risk is deterioration of the lighthouse foun- dation if no action is taken. The top of the existing timber mat is now approximately +2 feet (61 cm) MSL. When the lighthouse originally was constructed, the fresh groundwater level was above the top of these timbers, protecting them from dry rot. As the sea approaches, the groundwater level will continue to drop closer to MSL, exposing the timbers to dry rot and the lighthouse to serious settlement and possible collapse, if it remains in its present location (Lisle, 1985~.

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92 Criteria, Options, and Evaluation Because no action probably will lead to loss of the light- house, this option is not satisfactory. New Lighthouse This option was not considered in the interim report. A new lighthouse would be built a suitable distance inland from the shoreline. A replica of the present lighthouse would be one possibility; another would be to hold a design competi- tion. Cost It is impossible to provide a cost estimate for this option, because the committee could not predict the designs that would be considered. Evaluation Building a new lighthouse would be consistent with the history of the first lighthouse at this site, which was destroyed when the present one was built (Holland, 1968~. When the original 1803 lighthouse at Cape Hatteras became endangered by the sea in the 1 860s, it was replaced by the current structure. The original tower was destroyed. When the present tower appeared to be endangered in 1936, it was abandoned temporarily, and a steel tower was erected farther inland. When shoreline erosion was reversed in the 1 940s, the steel tower was abandoned, and the 1870 lighthouse was reactivated. This option has several advantages. The beach would not be affected by any new structure, and natural processes would not be impeded. lowed. An example would be set for other problems In coastal-zone management elsewhere, teaching the value of adapting to ecological forces rather than trying to hold fast to difficult positions. However, NPS's purpose is to preserve Cape Hatteras Lighthouse as required by its mandate to preserve historic Historical precedent would be fol ~. ~. ~Ha -

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Evaluation of the Options 93 structures. Construction of a new lighthouse, however imaginatively designed or built to resemble the original, would not serve the purpose of historic preservation. Recon- struction merely suggests the form and materials of the old structure. To replicate the lighthouse in all its detail, using original construction methods and materials, would be pro- hibitively expensive and might not be possible. For this rea- son, this option does not meet NPS's needs.

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6 Practical Consiclerations The committee discussed a variety of practical matters related to moving the lighthouse. Some would apply to any option chosen by NPS, others are specific to the relocation option. CONTRACTING CONSIDERATIONS Because of the unusual nature of lighthouse relocation and the intricacies of federal procurement regulations, the com- mittee believes it prudent to comment on the potential NPS contracting process. NPS must comply with the Federal Acquisition Regulations System ( 1987), as well as its own agency-specific procurement regulations and policies. Within those constraints, two considerations are of great importance in this matter: . . The need to select a well-qualified contractor from the small number of firms technically capable of performing such a project successfully. The need to allow appropriate flexibility regarding spe- cific methods to be used by the contractor to accom- modate realities such as local availability and cost of materials, as well as geological, structural, and engi- neering factors that will be inherent to the methods employed. 95

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96 Criteria, Options, and Evaluation A suitable way to select a contractor is a two-stage, negotiated procurement process such as that used by the U.S. Army Corps of Engineers on similarly complex projects involving potential risk, such as the Wolf Creek Dam cut-off wall in Kentucky. Offerors would submit qualifications (e.g., experience in similar projects, technical and engineering capabilities, and proposed supervisory staff). NPS would carefully screen the technical qualifications of potential con- tractors (with an independent advisory board if necessary) before specific technical and cost proposals for the actual work were solicited. Qualified offerors would provide a detailed technical pro- posal for carrying out the lighthouse relocation. This would include the following: Prepare detailed plans to strengthen the lighthouse to give it full structural integrity. Prepare detailed plans for the permanent foundation of the relocated lighthouse. Prepare detailed specifications for repairs to the gallery, lantern, stairs, windows, and masonry coatings. Prepare detailed plans for moving the lighthouse. Prepare detailed performance criteria for the move, including raising the structure, temporary dewatering and excavation, jacking procedure and controls, allow- able tilt, allowable accelerations and restrictions on jerk, control during the horizontal move, and final set down. With the advice of a board of consultants (and an inde- pendent engineering consultant with structural and geological expertise), NPS would review all submitted materials and select qualified contractors and request a financial proposal. NPS would be permitted to suggest minor modifications in any offeror's technical plans. Selected contractors would submit competitive cost proposals for the total project, which would include assumption of responsibility, and an appropriate insurance policy.

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Practical Considerations 97 Allowing flexibility in methods to be used implies the need to develop and specify performance criteria for the light- house relocation--rather than detailed methodological require- ments--in the NPS request for proposals. The committee emphasizes that no set of detailed methocls, including the committee's own example of a relocation concept, should be specified at the outset. Rather, performance criteria, such as the desired lighthouse site location, structural and architec- tural rehabilitation and strengthening, measurable damage limitations, allowable displacement of structural components, and other criteria suggested above are preferable for this type of project. INSURANCE Builder's risk insurance is available to cover any physical damage to a structure that results from external events, such as tornadoes and hurricanes during the contract period. Insurance also is available to cover contractor's errors or omissions. Maximum coverage would be limited to replace- ment value of the structure. Professional liability insurance is available to protect the relocation contractor and the engineering consultant from errors in design or specifications, including omissions. Limits are specified, but usually have a maximum of $5,000,000. Project wrap-up insurance can be obtained on a case-by- case basis, which includes the professional liability of all parties involved in design. An insurance company usually will insist on an independent review. INTERIM MEASURES The committee was asked to comment on interim measures for protecting the lighthouse. Such measures should be taken as soon as possible to reduce the possibility of damage or destruction of the lighthouse before long-term protective measures can be completed. However, no interim measure would provide enough protection to justify postponement of a long-term solution.

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98 Criteria, Options, and Evaluation The immediate danger to the lighthouse is the destructive erosion that might occur during a single storm or series of storms, rather than gradual, long-term retreat of the beach. A storm or storms might occur at any time of year, and would provide at most a few days' warning of their arrival. The most cost-effective interim measure--and one that could be implemented quickly--is beach nourishment in the bight immediately south of the southernmost groin. The ~ ~ ~ e ~ ~ ~ ^~^ ___ ~ _ (9 1 0 meters' ot neacn south of the southernmost groin. This would require a volume of sand 3 yards (2.7 meters) deep and 40 yards (37 meters) wide, totalling 120,000 cubic yards (92,000 cubic meters). The estimated cost of pumping this quantity of sand from the vicinity of Cape Point is $530,000. It should be recognized that this measure would be sacrifi- cial--the new sand would be lost in a major storm. But its purpose would be served if it buys enough time to implement a long-term protective option. committee suggests adding sand along Mu varos REHABILITATION OF THE LIGHTHOUSE . . ~. ,~. Constructed of mass brick masonry, the lighthouse is structurally sound. However, long vertical cracks are evident in the interior brick wall on the north and south sides of the lighthouse from the first landing level to the sixth land- ing level, extending intermittently for 150 feet (46 meters). These cracks pass through many points where stair stringers are anchored to the wall and through the sections that con- tain the window openings. Thermal effects probably caused these long cracks. When the outer cylindrical masonry wall of the lighthouse expands, high tensile stresses are induced in the inner cylindrical wall, because the two are tied together by a series of large, brick ribs. Cracks would be expected to occur in the interior wall along its weakest vertical sections. Movement of these cracks under thermal changes was confirmed by field instru- mentation measurements. Additional cracks also have been observed at various loca- tions where metal attachments are fastened to the interior wall. These cracks likely have developed as the result of corrosion of the anchorage for the attachments. _ . . . . . ~

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Practical Considerations 99 Although these cracks do not adversely affect the struc- tural integrity of the lighthouse, the committee recommended that they be cleaned and sealed with a high quality, flexible joint sealant to prevent further deterioration and intrusion of moisture into the wall. These necessary rehabilitation efforts and other preservation measures have been thoroughly defined by an architect/engineer team (Hasbrouck Hunderman Architects et al., 1986) and should be implemented as soon as feasible, regardless of the option chosen for long-term pro- tection of the lighthouse. The committee hopes it will be possible to open the light- house to public access on completion of relocation or other long-term protective measures. SITE DESIGN Before the lighthouse is moved, the future location of the dwellings and other structures that form the lighthouse com- plex must be considered carefully. It would be best to place these structures at the new lighthouse site so that their physical relationship to the tower will continue as it has been in the original location. The present visitor parking and picnic areas impinge on the historical setting of the lighthouse. The committee suggests that additional parking and other visitor facilities should be separated from the lighthouse complex and screened by natural vegetation. Every effort should be made to recreate the sense of isolation of the original 1870 light- house setting.

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