In Puerto Rico: Water Recovery Depends on Forest Recovery

by Marielena Alcaraz
Edited by Alison M. Jones, NWNL Director

Our guest blogger, Marielena Alcaraz, born and raised in Puerto Rico, experienced  2017’s Category 4 Hurricane Maria and its aftermath firsthand. Currently, she is obtaining a Master of Science degree at Columbia University in Sustainability Management. Her future plans are to work in environmental protection and social equality.

Picture1.jpgHidden Treasures of El Yunque National Forest (by Shirley Enid, Instagram: @paradojalogiica)

Puerto Rico

Puerto Rico is my home.  After the Spanish-American War in 1898, Spain ceded Puerto Rico to the United States. At that point, its set of Caribbean islands represent a United States Territory. By 1917, every Puerto Rican received U.S. citizenship.1 The US Census Bureau estimates that 3.3 million people populate the island, as of July 1, 2017.2

On September 20, 2017, Puerto Rico was hit by Hurricane María. Its Category 4 winds caused the death of close to 3,000 people.3 The storm compromised Puerto Rico’s electrical and water systems to a great degree for months. The entire island was left without electricity.  Over half the population had no access to potable water.4 When I left the island in January 2018, only around 55% of customers of the Puerto Rico Electric Power Authority (PREPA) had their power restored;and only 86% had access to potable water.6 This summer I returned to the island to visit friends and family and see what progress had been made since the hurricane. Although most have access to water and electricity now, services were interrupted throughout the summer by blackouts and water services were halted.

Water Sources in Puerto Rico 

According to the USGS, Puerto Rico’s water systems receive 83% of their fresh water from surface water sources, such as rivers, streams, ravines, and lakes – all now damaged by Hurricane Maria. Only 17% of Puerto Rico’s water delivery comes from groundwater, pumped from wells.7 According to the NRDC, before the hurricane, Puerto Rico’s water system, managed by the Puerto Rico Aqueduct and Sewer Authority (PRASA), violated more EPA regulations than any other U.S. state or territory. PRASA served 99.5% of customers with water that did not measure up to Safe Water Drinking Act standards.8

Water conditions worsened after Hurricane María hit. Raw sewage and sediments flooded rivers and reservoirs as power outages kept sewer treatment plants and pumping stations out of service.9 Without treatment, water in Puerto Rico is considered undrinkable. Thus, residents were instructed to boil their water for 10 minutes before consumption, due to risks of E. coli and other bacteria.10 Without operational water utilities or access to safe drinking water, residents relied on ravines and streams. Many streams and ravines were infected with rat urine, causing spikes in gastrointestinal issues and leptospirosis cases.11 Although water is now restored and considered drinkable by authorities, most people in remote areas distrust the service and continue to boil water or strictly stick to bottled water.

El Yunque National Forest: A Critical Water Source 

Screen Shot 2018-09-18 at 11.47.13 AM.pngMean Annual Precipitation map (from USDA report)12

El Yunque National Forest covers 28,900 acres [11,695.415 ha.] in northeastern Puerto Rico. Resting in the mountains of Luquillo, it is a national treasure for Puerto Ricans and the only National Forest in the U.S. Tropical Forest System. The highest peak stands at 3,281 feet [1,000 m.] above sea level.13 El Yunque’s lush, forested land contains one of the greatest biodiverse plant ecosystems in the U.S. Forest Reserve.13

Have you ever looked at a Magnolia portoricensis? Doubtful, as it is one of 23 plant species found only in this tropical ecosystem. This magnolia is located in the Luquillo mountains near the Rio Grande Municipality.14

Picture3.jpgMagnolia Portoricensis (Creative Commons)

Eight rivers originate in the mountains of El Yunque National Forest.  When combined, these rivers are one of the major water providers of the island.  The structure of the forest creates a unique, natural water filtration system. Moss and plants around the tree trunks collect rainwater and filter it as it runs down mountain paths and rivers.

The El Yunque forest has served up to 780,000 citizens,12  providing 20% of drinking water to the island.12 There are over 34 water intakes on the island that collect water naturally filtered en route down through the forest. That water is then distributed through pipe systems to treatment systems. To find one of those intakes, located inside the forest, it took six days of debris removal.15

On September 21 after Maria moved on, the forest awoke barren, broken, and brown. The breaking and uprooting of trees caused over 300 landslides. It affected the water quality, eliminating El Yunque as an important source of drinking water.  As Hurricane María stripped the forest bare, it killed over one-fifth of the trees.16

Research updates on “disease spikes” due to Maria were released this summer while I was on the island.  In June, the U.S. Center for Disease Control released the numbers of leptospirosis deaths caused by contaminated stormwater carried by rats. Lab statistics show these cases doubled after Hurricane Maria. The Centro de Periodismo Investigativo (CPI) and CNN together stated that seven medical experts agreed that an unreported “epidemic” occurred after Hurricane Maria.20

Picture4.jpgEl Yunque Falls (Creative Commons)

Picture5.jpgThe Aftermath of Hurricane Maria in El Yunque (USDA)

Shrimp Filter Forest Waters?

The good news is El Yunque’s trees don’t work alone. There are other filtering factors in El Yunque’s water.  In upstream flows of its rivers, Caribbean dwarf shrimp (Micratya poeyi) feed off sediments and algae that float in the streaming water. Areas in the forest with higher counts of these shrimp show higher qualities of water.  This confirms the important impact these small critters have on the conservation of the forest and the water cycle.  If this species of shrimp disappeared because of a hurricane or other reasons, water quality would deteriorate even if the trees of El Yunque rebound and grow.

Although we can’t yet establish the long-term effects of Hurricane María on wildlife and flora, we can predict the presence of the dwarf shrimp, based on past hurricanes. In 2006 a study conducted in El Yunque’s Luquillo Mountains17 focused on the effects of Hurricane Hugo (1989 Category 4 landfall in Puerto Rico) and Hurricane Georges (1998 Category 3 landfall in Puerto Rico). The study shows little change after these storms on the abundance of shrimp and other microorganisms that migrate up rivers. Thus, we can infer that the shrimp population will not be affected by the devastation of Hurricane María.

Recovery efforts continue today to reestablish the water quality of the rivers in El Yunque. Such efforts include clearing debris from trees and landslides to diminish sediments in the water and open trail access to tourists and citizens. However, scientists estimate that it will take years before the forest completely recovers.18

Picture6.jpgForest Loss in El Yunque  (Via Instagram @carlalopezlloreda)

This month, the Puerto Rico Aqueduct and Sewer Authority reported that 99% of Puerto Ricans using their service (covering 97% of the island) have water restored to their homes. However, families not connected to that water utility company rely on local wells that were damaged before the hurricane.19 These families, in 230 rural neighborhoods, currently use bottled water for drinking and natural springs with high probable risk of contamination. Hopefully, restoration of El Yunque will proceed quickly, so that all families on the island will have clean fresh water on which they can rely – in good weather and bad – in the near future.

Note: Revised Oct 4, 2014. Three phrases reworded for more accuracy (in 3rd, 4th and 9th paragraphs). Feel free to contact us for more information.


1. Puerto Rico – History and Heritage. Smithsonian Magazine, Nov. 6, 2007. Accessed August 2018 by MA. Link.
2. United States Census Bureau. Accessed August 2018 by MA. Link.
3. Ascertainment of the Estimated Excess Mortality from Hurrican María in Puerto Rico. The George Washington University. Accessed August 2018 by MA. Link.
4. Hurricane Maria Update. FEMA, November 6, 2017. Accessed August 2018 by MA. Link.
5. Ellis, Ralph and Santiago, Leyla. Puerto Rico: Power restored to 55% of customers, governor’s office says. CNN, Dec 29, 2017. Accessed August 2018 by MA. Link.
6. Galarza, Milton Carrero and Simmons, Ann M. Four months after Hurricane Maria. Los Angeles Times, Jan 30, 2018. Accessed August 2018 by MA. Link.>
7. Source, Use, and Disposition of Freshwater in Puerto Rico, 2010. USGS, July 2015. Accessed August 2018 by MA. Link.
8. Threats on Tap: Drinking Water Violations in Puerto Rico. NRDC, May 2017. Accessed August 2018 by MA. Link.
9. Raw sewage contaminating water in Puerto Rico after Maria. CBS News, Oct 17, 2017. Accessed August 2018 by MA. Link.
10. Kamin, Jennie. Puerto Rico teenagers take post-Maria water safety into their own hands. Grist, March 26, 2018. Access August 2018 by MA. Link.
11. Bascomb, Bobby. With government sidelined, citizen scientists test water quality in Puerto Rico. PRI, Sep 16, 2018. Accessed September 2018 by MA. Link.
12. Quantifying the Role of Forested Lands in Providing Surface Drinking Water Supply for Puerto Rico. USDA, September 2017. Accessed August 2018 by MA. Link.
13. El Yunque National Forest. USDA Forest Service. Accessed August 2018 by MA. Link.
14. Global Tree Specialist Group. Magnolia portoricensis. The IUCN Red List of Threatened Species 2014. Accessed August 2018 by MA. Link.
15. Public Update: Healing El Yunque, Serving Communities. USDA Forest Service. Accessed August 2018 by MA. Link.
16. Assessing The Damage To Puerto Rico’s Rain Forest. Weekend Edition Saturday, NPR, Oct 28, 2017. Accessed August 2018 by MA. Link.
17. Covich, Alan P.; Crowl, Todd A.; Heartsill-Scalley, Tamara. 2006. Effects of drought and hurricane disturbances on headwater distributions of palaemonid river shrimp (Macrobrachium spp.) in the Luquillo Mountains, Puerto Rico. J. N. Am. Benthol. Soc., 25(1):99–107
18. Hurricane Recovery. USDA Forest Service. Accessed August 2018 by MA. Link.
19. Schmidt, Samantha and Voisin Sarah L. Puerto Rico After Maria: ‘Water is Everything’. The Washington Post, Sept 12, 2018. Accessed September 2018 by MA. Link.
20. Pascual, Omaya Sosa and Sutter John D. Deaths from bacterial disease in Puerto Rico spiked after Maria. CNN, July 3, 2018. Accessed September 2018 by MA. Link.

6 thoughts on “In Puerto Rico: Water Recovery Depends on Forest Recovery

    1. Hi Jay,
      Thank you again for your concern. Regarding this rainfall map – it was taken from a USDA study and depicts “the mean annual precipitation of mainland Puerto Rico, averaging years 1963–1995.” Please view footnote number 12 for the full study (Also linked here: to learn more about the methodology used to obtain this data. Any further concerns about the validity of this map should go to the USDA.
      No Water No Life

  1. In my 51 years of working on issues related to the water resources and environment in Puerto Rico, until this paper, I had never read so many misconceptions and erroneous information about these issues in the island. I do not know where Marielena Alcaraz obtained all this falacies and erroneous views about how the water cycle in the island “behaves” and responds to hurricanes and droughts. Certainly not from the scientists in and outside of PR that deal with these issues on a day to day basis. It would take me many pages to refute the many errors in data, procedures and conclusions in this paper. I review serious scientific papers, and this in the category of fiction and media that derives conclusions from thin air. She can start by visiting my web page “Recursos de Agua de Puerto Rico” (, and then talking to the experts such as Dr. Ariel Lugo at the International Institute of Tropical Forests in Puerto Rico. My advice to Allison M. Jones is to delete this post from this blog.

    1. Hi Mr Ferdinand Quiñones,
      I would like to follow up with you and let you know we have made some revisions to the blog. Please contact us if you have any further questions. Thank you.

Leave a Reply