Vaccarino Associates are the prime consultant for Paralanaturaleza.org in the planning effort. We have proposed a five-pronged approach: 1. Coastal reforestation using endemic and native species missing from the surviving existing trees. 2. Rehabilitation of forest, dunes, and freshwater pond habitats at an ecological level in a highly accessible and visible area, while providing recreation and education for the community and visitors alike. 3. Creation of entrepreneurship opportunities in Culebra that support conservation of habitats while building resilience. 4. Active participation of the community in the recovery, maintenance and conservation of the coastal forest, water, and dune systems, increasing community ownership and long-term monitoring and commitment. 5. The adoption of a mitigation action plan, parallel to the recovery plan, which addresses both preparation and response for future climatic events, through adaptive planning and the development of guidelines for the benefit of visitors and residents.

AN IMPERMANENT LANDSCAPE

Dunes are shock absorbers that protect the coastal environment and back beach, accumulating and storing sand in normal conditions, while releasing it back to the ocean during storms. They act as dikes against flooding and as a reservoir of sand to replenish the beach. Dunes develop and grow with the help of plants that hold and trap the sand coming towards the direction of maximum wind-blown sand source.

Unvegetated dunes are vulnerable to destruction by the same forces that form them—waves and wind. Sand is temporarily stored in various areas of the beach: off shore underwater bars, tidal beach, back beach above normal high tide, and in the dunes.

During the storm season, waves drive high onto the beach and pull the sand off the foreshore, and the back beach, depositing it on enlarged offshore underwater bars. These storm bars absorb the wave’s energy, thus reducing the amount that actually reaches the back beach during smaller storms. During lengthy storms, sand will be removed from the beach further, and an equilibrium profile is eventually reached. The larger a storm, the more sand removed. A constant process of erosion and deposition is therefore causing the impermanence and perpetual motion of the dunes’ landscape: presence and absence are determined by conditions and circumstance.

A RELENTLESS PERSISTENCE

Constantly changing, the beach shoreline and dunes profile provide very unstable growing conditions for the dune vegetation, but many plants are well adapted and even resistant, especially the herbaceous perennials, crawling vines and a variety of grass species that are able to grow in the front and tail of the dune facing the ocean’s wind and salt spray.

In Flamenco, these include Canavallia rosea, Ipomea pes-caprae, Sesuvium portulacastrum, Cakile lanceolata, Scaveola plumeri, Batis maritima, Suriana maritima, Ernodea littorais, Hymenocallis latifolia, among others, and many species of grasses.

Many grasses develop a very deep root system, growing progressively vertically with the dune’s movement, generating new roots at each node. Other plants grow horizontally, using modified stems (stolons above ground or rhizomes below ground), which may also hold nutrients, spreading across and under the sand cover.

In either case, dune plants hold as a smooth infrastructure, formless yet always changing, keeping the sand dune from disappearing. The surface of the sand can be interrupted and moved, leaving no trace if the underground plant stems remain, colonizing a deep layer like an aquifer that sustains life to always return.

THE SHAPE OF EROSION

Vegetation also promotes the accumulation of sand from wind-blown sources around their stems, and over time this causes dune growth. Plants growing close to the ocean reduce the impact of wind velocity and trap the sand, keeping much of it in the immediate vicinity of the beach.

DUNES BEFORE AND AFTER IRMA AND MARIA

The tan color indicates the large sand dune area, which was covered by a very lush dune vegetation plant community with narrow openings in correspondence of the pedestrian access to the beach. In 2004, the vegetation covered almost completely, both the frontal dune and the back dune zone, the latter being amore protected area leeward of the front dune.

The front dune was covered mainly with herbaceous plants, vines and grasses able to resist the most exposure to salt spray, like Ipomea pes- caprae, which was abundant. The back dune zone supported many shrubs, especially Coccoloba uvifera, other trees and vines, as well as grasses and other herbaceous plants.

The front dune system has collapsed in many areas at of habitat. It may take a long time before slow waves push Flamenco with a deep scarp on the foredune and a number the sand, from sediment stored on the lower shoreface of the of blowouts especially in Zone B and Zone C, as well as ocean floor, back into the beach and migrate into the dune Zones E, F, G, and part of Zone H. Sand erosion continues to with the help of wind.

CARRYING CAPACITY

Most beach users at Flamenco Beach want to sit in the shade of palms and other trees, to enjoy the view and ocean breeze while they are at the very top of the front dune. This habit has increased after the hurricanes, because trespassing is easier without plants in place. In the process, people damage the already exposed plant roots and eroded embankments; they scatter litter and leave their impact, day after day. We need to devise a system that prevents access or transit in the most sensitive dune areas before we even attempt to repair the damage, while keeping Flamenco open to the public.

DO WE HAVE TIME TO WAIT?

The question is, with climate change affecting the intensity of future storms and the rise of ocean levels, and with the continuous heavy impact on the dunes of the beachgoers, which accelerate plant loss and sand erosion, do we have time to wait for the ocean waves, wind, and plants to slowly rebuild the eroded dunes at their pace? In other words, should natural processes be the only means of repair when facing worsening impacts of climate change?

How long will it take before another storm carries away another piece of dune infrastructure, our last reservoir of sand available to rebuild Flamenco Beach? We cannot stop hurricanes from impacting our beaches but can adopt regenerative and monitoring systems where vulnerability is reduced and recovery time is identified, assessed, and enhanced.

CONTROLLING ACCESS

We suggest closing off three new access points created by people or by storms and flooding that did not exist before. All the other points of access should be kept open but regulated with signage, by dune walkovers, and by rope railings to limit the impact of foot traffic on the dune vegetation. Access walkways will be made of wood and act as a bridge around or over the dune. Access points not heavily used, can receive quite narrow and less visually intrusive wood boardwalks or structures for access.

Access number 14, 12 and 8 can continue to be used for maintenance vehicles as they are probably located in what was a blowout area and can be kept open at ground level. However, erosion control and sand building devices should be inserted diagonally on both sides of the dune opening, without blocking the passage of vehicles to help keep the access open, oriented at an angle to the prevailing wind direction.

STITCHING THE DUNES IN TIME

We need a careful surgery of all the open wounds left in the dune habitat before it is too late. We cannot restore all at once or recreate something that is constantly changing (the dune system) and which was never fixed in historical time or form.We can, however, envision a framework where individual interventions will create the means to accelerate the progressive healing of the eroded scarp of the front dunes, in whatever form it will want to manifest over time. Are they needles-like temporary insertions that have a use, and that can take abuse?

Are they driftwood-like bars trapped in the dune from ocean surge, to suggest you can pass, or not trespass, according to their direction? Are they walkovers, elevated fragment of broken platforms, or seats or tables scattered about by tides at the same time? As we enter design development, we will assign a specific function and form to these images of structural catalysts or indicators. We envision small and medium wood walkovers that disappear in the landscape, and are notable not by bright color but by directional signage. Seating and tables will be incorporated into the design of the linear platforms, which will come in two sizes for use flexibility. We want the decks to seem as if they float over and above the vegetation, as gently drifting rafts.

WORKING WITH THE WIND

Dunes are intimately connected with the instability of the weather, with the turbulence of the air and wind. They cannot be bound, retained, but can be affected and modified in their growth and form, if we engage and fabricate devices that interact with the phenomena of the wind. Walls set in the bed of a stream slow down the current and cause the silt carried by the water to be deposited in distinct layers, making islands or mounds whose position we anticipate, but whose random shape is not always predictable.

Similarly, the wind, when attracted and channeled with our instigation, designs intimate and ephemeral places in the curves of the sand where we also make our marks. We want people to fall in love with the instability and inner energy of the dunes, to appreciate this fragile landscape in constant transformation. Each group of volunteers that helps re-build a specific zone of the 800 feet of eroded scarp, will also have to adopt and police that zone, while monitoring dune and plant growth. Breaking the task into smaller community projects will make a daunting effort more manageable, more visible, more personal, and in the end, educationally transformative.

FENCES FOR SAND TO TRESPASS

Sand fences are porous, temporary filters that help rebuild the dune much faster. Rather than barriers, they are sieve instruments that, like plant stems, affect and channel wind turbulence and movement. Wind is not blocked in its passage, but its velocity is reduced enough that the sand carried by it drops into, through and behind the fences because of the 50% porosity of their wood slats. Since they are typically made of light, widely spaced wood slats, sand fences can be constructed and installed easily with the participation of volunteers and local community groups.

They are placed on the seaward side of the dune to help it grow. They also protect the recently planted dune grasses and ground covers from people walking over them.

We suggest installing sand fence posts seaward of the toe of the new dune scarp we want to heal at least 8-10 feet away from the scarp depending on space and conditions. Additional posts and rope fencing may be installed in the back dune, between walkovers and decking platforms to prevent access in designated areas.

Sand fences will be perpendicular to the direction of the wind and laid out in sections, with a maximum length of 100 feet. Periodical gaps in the fence line will in fact prevent entrapment of storm surge water or rainwater in the trough between existing dune and new dunes forming. If necessary, to accelerate the process, a second tier of fences may be placed later on the back slope of the new dune created by the first fence line. This will increase dune height and fill any valley between existing dune and newly formed dune.

The eroding scarp and exposed roots may benefit if immediately protected with dry Sargasso algae, and other organic matter, held by dead twigs and small branches that can decompose while sand accumulates slowly over, developing the needed sandy soil medium for new roots to grow deep inside the dune. Dune walkovers will be designed and built in different size depending on their location and traffic, from 2.5 to 5 feet wide. They will have railings, and will be high enough to allow the potential growth of the dune and its vegetation underneath. They will be oriented at an angle to the prevailing wind direction, to encourage the accumulation of sand.

EROSION AND DEPOSITION

The back dunes at Flamenco Beach have also lost their sand and organic matter, and much of their sand has shifted on the path or camping ground. We have identified a few areas where we can rake the sand back into the back-dune zone, after proper organic amendment. The new back dunes should not be higher than four feet and never steeper than a normal angle of repose. Since they are typically made of light, widely spaced wood slats, sand fences can be constructed and installed easily with the participation of volunteers and local community groups.

Maintenance guidelines and monitoring will guide volunteers to recognize problems, or to welcome newcomers, as part of the native plant mix; everyone will understand that this is not a static garden that should be fully controlled. The back dunes project will be incorporated with the reconstruction of the walkway.

People will be able to see the plants closely while they walk to reach the campground, the bathrooms, or the food kiosks. To those who were directly involved in the planting effort, the growth and evolution of these plants may carry feelings and an emotional bond that could go beyond visual interest.

WEIRS FOR A FLUID LANDSCAPE

We will not attempt to reconstruct and reproduce the back dunes in a prescribed, immobilized form, stripping their dynamism into a mere abstraction. They should always be free of movement, if they are alive. Conceptually, we are thinking to help their process of self-organization with “ribbons” of vegetation, to partially hold the mounds of sand on one side like a weir or a small check dam would do for turbulent water flowing downstream.

These green weirs will be a “solid” counterpoint that protects the sand from disappearing during storms, but also a device able to register the subtle variation landscape of sand in normal weather conditions, making the changing form of the dune landscape more apparent. The flow of these drifts will echo the rhythmic movement of the bars or splinters- like wood structures and walkovers, which mark and help heal the sores in the dunes from pedestrian use and abuse. The overall experience, when one is part of the dune landscape, will feel like being within the flux of the ocean, yet suspended over the waves or wind current, stirred like a driftwood on the sand blow, slowly returning to the dunes, returning home.

UMBRELLAS FOR SHADE

To prevent people from picnicking and sitting on exposed roots of palms and sea grapes, we are suggesting that ACDEC provide beach umbrellas for rental, as it is commonly done in non-tropical managed beaches across the world. Beach umbrellas will provide the necessary shade taking people away from the dunes zone, closer to the ocean, and thereby speeding up the recovery process. Wood platforms will also be offered on or nearby the crest of the dune in the most popular areas, which may be for rent to provide income. Rope fencing incorporated in the design of the decking will limit foot traffic to the deck areas, only so that compaction and erosion will be minimized.

Beside these planning studies, we produced project design in plans and details for construction of the "needle" deck platforms, wood bridges, bioretention beds, and re-planting for all phased areas of the site. The buildings have been reconstructed but the site recovery implementation is on hold until sufficient funds for construction are secured.