Are Laguna’s hot springs losing steam?

| Written by Fred Dabu

Researchers, mostly from the University of the Philippines, have pointed out that over-extraction of groundwater by hot spring resorts in Calamba and Los Baños in Laguna Province can cause a variety of problems, such as a drop in groundwater level and competition for water supply in the near future. Will Laguna’s hot springs also “lose steam” or cool down due to over-consumption?

 

Municipalities of Calamba and Los Baños located at the foothills of Mt. Makiling and Mt. Banahaw. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)
Municipalities of Calamba and Los Baños located at the foothills of Mt. Makiling and Mt. Banahaw. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)

 

Among the tourist attractions that Laguna is known for are its hot spring resorts and water spas sprawling in areas endowed with plenty of groundwater made warm by geothermal activities in the foothills of Mt. Makiling and Mt. Banahaw. The researchers were concerned that “the increasing number of hot spring resorts in the area and the increasing number of visitors entail greater demand for groundwater to be used in the pools,” especially during the summer months from March to May, and in December, peak periods for these business establishments.

The research team comprised Karen Ann B. Jago-on of the School of Urban and Regional Planning (SURP) in UP Diliman (UPD); Fernando P. Siringan of the Marine Science Institute (MSI) in UPD; Rosana Balangue-Tarriela of the National Institute of Geological Sciences (NIGS) in UPD; Makoto Taniguchi of the Research Institute for Humanity and Nature in Kyoto, Japan; Yvette Kirsten Reyes of SURP; Ronald Lloren of MSI; Maria Angelica Peña of NIGS; and Elenito Bagalihog of the National Water Resources Board (NWRB) of the Philippines.

In an article published in the Journal of Hydrology: Regional Studies, Volume 11, June 2017, these researchers warned of over-consumption of groundwater in selected areas in Laguna for domestic, agricultural, commercial and industrial uses; and, of possible negative effects of unregulated water use on affected populations, such as conflict or competition over the use of available water.

Through their study, they are calling for improvements in the implementation of existing water use regulations and the strengthening of partnerships for the sustainable management of groundwater resources. The researchers are also asking for the crafting and implementation of specific water use regulations for hot springs. The article was one of the team’s research outputs under a bigger research project on human environmental security funded by the Research Institute for Humanity and Nature (RIHN).

Their study, “Hot spring resort development in Laguna Province, Philippines: Challenges in water use regulation,” projected the impact of the activities of hot spring resorts in Calamba, where 466 of these were registered, and in Los Baños, where 42 were registered as business establishments with their respective local government units. Only a handful of them, however, were registered with the NWRB.

 

Location of private pools and resorts based on online search and actual survey. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)
Location of private pools and resorts based on online search and actual survey. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)

 

The NWRB is the lead government agency that “coordinates and regulates all water-related activities in the country that have an impact on the physical environment and the economy.” Estimates on water consumption were made based on data from government agencies and at least 65 resorts surveyed. The researchers further warned that any increase in the population and in commercial and industrial activities in these areas also leads to increase in water use and demand.

According to the study, most of the resorts, typically having one adult pool (usually 6.8 meters × 11.12 m in size and about 1 m to 2 m deep) and one children’s pool (about 3.12 m × 3.82 m in size and 0.6 m to 0.9 m deep), were built only in the past 13 years and operate without water use permits. These “use 1 or 2 motor pumps, and it usually takes about 7 hours to fill the pool with water. The depth of the wells ranges from 3 m to 100 m. The average depth of the wells is about 29 m.” Since the “swimming pools are drained of water every booking of new guests, which on average is about 3 times a week during peak periods of tourist arrivals, the estimated average volume of monthly water consumption per pool is around 1,500 m3 during peak periods and about 700 m3 during lean periods or during the rainy months,” the study reveals.

 

Used water are drained on the streets. (Photo courtesy of research team)
Used water are drained on the streets. (Photo courtesy of research team)

 

The researchers reported a “huge demand of groundwater from these water resorts” based on the estimated total monthly water consumption of registered resorts during peak season in Calamba (around 665,260 m3, or up to 77% of the domestic consumption serviced by the Calamba Water District) and in Los Baños (about 59,959 m3). Furthermore, new data on the pools’ water temperatures, gathered from previous and recent research initiatives, point to a general “decrease in temperature through time”, such as an observed cooling down by 5 to 8 degrees.

 

Estimated monthly water consumption (cu.m.) of surveyed resorts in Calamba and Los Baños during peak season. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)
Estimated monthly water consumption (cu.m.) of surveyed resorts in Calamba and Los Baños during peak season. (Source: Journal of Hydrology: Regional Studies, Volume 11, June 2017, https://doi.org/10.1016/j.ejrh.2015.11.020)

 

There have also been some reported changes in the volume of water, such as a “decrease in water yield and flow rate from pumps; increase in the time to fill the pools; and decline in water level making it necessary to dig deeper wells,” due to “unrestrained exploitation of groundwater.”

If water extraction from Laguna’s hot springs is left unregulated, as the study warns, water resorts might also “lose steam” (a metaphor for possible consequences, not due to geothermal activities), or could literally cool down (as new data suggests), due to decreasing groundwater supply and over-exploitation of the resource now and in the future.

That’s worrisome—but if you take that hot dip now, will you be contributing to the problem down the road?