Playa de San Miguel, Yucatán: What to do to ensure its long-term sustainability?

Playa de San Miguel, Yucatán: What to do to ensure its long-term sustainability?

In Yucatan we continue, to this day with the debate on how to recover our beaches, from the effects of erosion. Unfortunately, as many years ago, the debate returns and is reduced to the discussion of the  the groins (breakwaters) are the solution or are harmful to the beaches. The approach to this discussion is precisely the origin of the problem, since the groins are neither good nor bad by themselves. The debate that must be carried out should be focused on either putting sand in circulation or retaining it to recover the beach.

In this way, the conclusion of the debate becomes simple: the only opportunity to recover the beaches in a sustainable way is NOT to retain sand in EXCESS, but to favor that it passes in front of our beach in sufficient quantity so as not to affect others. This generates a slow but stable recovery. It is very evident in the area of ​​Yucatan summer estates that the best beaches coincide with a minimum or total absence of structures.

What is happening on the beach of San Miguel confirms the above. Only insofar as we ensure that we do not retain excess sand, we will ensure a sustainable beach recovery and the non-impact of nearby beaches. In other words, when we intervene on a beach, what we really have to worry about is not to affect the neighboring beach.

Figure 1 image exemplifies the foregoing. However, without going into what works were executed in this section, what is important and conclusive is that now only the MINIMUM NECESSARY of structures are being put in place (leaving aside the debate of which type of structures they are) therefore it is partially retaining sand, while making sure  the sand circulates. This is the key to a sustainable recovery.

Figura 1. Comportamiento de la playa de San Miguel en zona libre de estructuras.

Figure 1. Behavior of San Miguel beach in free of structures zone.

In Yucatan, there is the circumstance that beaches recover ONLY from east to west (see figure 2). This is so because this is the average natural movement in which the sand circulates (EAST to WEST) throughout the year. A great lesson that we have all learned (government, researchers, consultants and beach users) is that we cannot force the speed with which nature recovers a beach since nature is the one that takes care of itself if we leave it alone and, instead of waiting for nature to adapt to our timeframe. Intervene a stretch with groins, parallel breakwaters or any other alternative without ensuring that the circulating sand comes from the East is a bad idea. Pretending to accelerate the natural recovery times is even worse.

Figura 2. Comparativa de imágenes aéreas en zona de San Miguel

Figure 2. Comparison of aerial images in San Miguel area

Our opinion is that groins are the last solution that should be proposed in Yucatán. It is something similar to doing surgery to a patient when he only needs rest. But, if the decision is to use groins, it is more important to ensure the circulation of sand towards the West than the retention at a specific point. Both in San Miguel and in the entire Yucatan coast, although every intervention must be evaluated, the most important thing is the sustainable circulation of sand that comes from tens of kilometers to the East. Likewise, what is done in San Miguel should consider the stability of the beaches along several kilometers to the west.