The accelerated disappearance of Portocristo beach

ManacorIf you haven't been numbed by yet another alarming and sensationalist headline, I think we can agree that the overall appearance of the beach is quite different from what we all have after a few decades, as can be seen in the attached photographs (we don't know history, and personal memory is very reputable). Unfortunately, this is not a phenomenon exclusive to Portocristo, and many coves in our area are already suffering the effects of coastal regression to a greater or lesser extent. As with the vast majority of phenomena, this situation is not due to a single cause; multiple factors influence, interact, and magnify it.

If you want to get (more) nervous, just look on the Internet at some of the models of the evolution of the beach profile under different scenarios of sea level rise over time (such as the one from the CAIB, available at https://ideib.caib.es/visor/ of the projectPIMA-ADAPTA-COSTA). Without knowing what parameters have been taken into account or what variables have been used to model the forecasts (beyond anthropogenic global warming and coastal geography), I believe these estimates are even optimistic, since it is possible that local causes and factors have not been sufficiently taken into account and that the situation will soon be even faster and worse.

If we focus on the specific case of Portocristo, I believe that the local factors are mainly due to anthropogenic causes and that I consider that, from greatest to least importance, they would be these three facts:

Construction of the hammer

The existence of this emblematic structure for some 70 years, presumably to avoid the action of the incident easterly waves at the mouth of the Riuet, has caused the wave front to refract towards the Cuevas Blancas area with virtually no loss of energy (and so fortunately, a bridge was later built). This causes the waves to reach the beach pavement with full force, since the profile of the submerged beach is very steep. This phenomenon is aggravated by the fact that the storms are usually "wind sea" (waves with quite banked and continuous waves, since the wind field where they are generated is very close) and by the small continental shelf we have in Mallorca (the waves reach the beaches with greater force, since there is great depth and close distance from the coast, and the force increases as the depth of the water column decreases). This energetic and disorderly swell, even more so in Portocristo Bay where its natural shape already causes the wave to undergo reflection, refraction, and diffraction phenomena—the sunken Roman boats are a testament to this—has been exacerbated by the hammer. All of this causes sediment to move to the submerged part of the cove and toward the mouth of the Riuet River.

Construction of the Coves Blanques promenade

The beautification and construction of the new promenade in 2000 has exacerbated the beach retreat, not only by reducing the free beach area but also by worsening the effect of waves in the area. The wall has taken up space available to dissipate wave energy on the natural beach—which, it must be said, was already minimal—and, even worse, during large storms, the waves directly rebound and are reflected back out into the bay, aggravating sediment loss and accelerating erosion.

Waterproofing of the urban area

Another important issue is the progressive transformation of the natural environment of the beach into a human-made one, with the progressive paving of the urban center with asphalt streets and, even worse in this regard, the tiled walkways that hinder the absorption of water into the ground. This turns part of Portocristo's core into a large funnel that drains rainwater to the beach. In addition to the flooding, the influence of a regular pattern of intense rainfall, with less water absorption on land, and other issues must also be taken into account, such as possible errors in the design or poor maintenance of the water pipe network, both stormwater and sewage. For all these reasons, a large amount of water, whether solely from rain or also from sewage, drains directly onto the beach and carries sand into the submerged part of the bay. This amount of displaced sediment can be considerable, as can be seen after some torrential rains. Furthermore, all of this, including the rainwater runoff and subsequent sand erosion, poses a significant challenge for the proper condition and functioning of beach services, especially with regard to sun loungers and walkways.

Regarding measures to be applied directly to the beach and the sand, various restoration methods exist and are currently being used, both natural and artificial. A comprehensive approach to this problem is gradually being applied, considering that each beach is unique (what may work for one beach may not work for another), that perhaps different techniques should be applied depending on the situation, and that traditional mass sand regeneration "is useless," often a waste of time, often a general problem), even though they make people believe that "politicians already do things."

We may not be able to reverse the situation (waiting for a miracle), but we can at least minimize the more or less unpleasant and immediate changes that will come (such as, for example, the soon-to-be reduction in income because they've had to remove sun loungers because there's no more room). I'd like to believe that in a few decades, the beach won't be a tiny fraction of what it is today if we act quickly and decisively. If anyone is interested, simply has something to say or make a correction in this regard, or, better yet, has some decision-making power on the subject and finds it useful, I'd be more than satisfied with this writing.