For some time now, Ronald Guzmán and his family have been using rainwater to wash clothes, flush toilets and clean the house.
“We are in a constantly growing community and there is often a lack of water here, even though we have a good aqueduct. That is why it is important to make the most of what nature gives us, in this case, the rains,” said the neighbour of Bahia Ballena, a community located in the South Pacific of Costa Rica, about three hours from the capital.
To do this, in the back of the house, Guzman installed a system that allows to store the liquid after a downpour. “It is a very practical system: it consists of canoes that direct the water from the roof to a 450-liter tank and from there the distribution goes to the areas where it is going to be used,” he explained.
The technical term is SCAPT or Roof Rainfall Collection System, and its objective is to take advantage of the elevated and inclined position of the roof to direct rainwater towards a tank. Like no other surface (such as the ground), the water collected is considered of good quality and suitable for use in domestic activities and even for watering gardens, orchards and animal troughs.
According to Guzmán, the house did not even have to be changed. All that was required was to put a canoe, downpipes and the structure of the tank with its pipe. In fact, by placing the tank on top, gravity was taken advantage of to avoid pumping, which would entail a cost in electricity. In total, the work amounted to 215,000 colones (about US $358).
“The main benefit I see in paying the bill. Previously we paid, on average, about 15,000 colones (US $25). What we pay now is 9,000 colones (US $15). But you have to keep in mind that in this property there are two houses and the minimum charge is 5,000 colones (US $8.34). So, what we are really paying for water consumption is just 4,000 colones (US $6.67),” Guzmán said.
The 450-liter tank is additional. The family of five still needs water from the community aqueduct, which must supply more people day by day.
About seven years ago, when Tania Calderón began as a director of the Association of Administration of the System of Aqueducts and Sewers Communal or ASADA of Bahia Ballena, the spring was no longer sufficient and water was scarce in the community, so they had to resort to cuts in supply by the hour.
They had two wells, but “around those wells what happened was that they had built many houses and that worried us about the issue of water quality, as well as how expensive it was to be pumping. It cost us about two million colones (about $3,335) a month for electricity,” Calderón said.
According to data from the Osa Municipality, as of February 2015, Bahia Ballena had 3,306 inhabitants in an area of 160 square kilometers. In total there were 2,017 homes, but the number continues to increase due to second homes or beach houses.
For that reason, in 2017, the ASADA captured a new spring to supply the demand and the wells were left as backup. “At the moment we have enough water for the entire population and we calculate that for the next five years, but the community is still in constant development,” Calderón said.
The community also borders the Ballena Marine National Park, which is the fourth most visited protected wilderness area in the country with about 143,000 visitors a year.
This national park is recognised as a humpback whale breeding site, which has become the attraction of the area. In fact, in the last 20 years, tourism has displaced agriculture and fishing as economic activities.
“In coastal areas such as Bahia Ballena, the activities of the tourist and commercial sector demand large volumes of water for cleaning offices, lodgings, boats, vehicles, swimming pools and the irrigation of green areas, which puts at risk the availability of drinking water for human consumption. This demand could be met with secondary sources such as rainwater, for example,” said Catalina Molina, president of Keto Foundation, a non-governmental organisation working in the area since 2009.
In addition, visitors don’t necessarily have a water culture geared toward rational use. “Tourists are not aware of the waste they cause. I’ll give you an example: on the beach there is a public fountain that was placed there to give water to the surrounding houses and tourists use it to wash cars, surfboards and to remove sand. What’s more, one of the neighbours told us that they usually leave the key open. That is drinking water that is being wasted,” Calderón said.
The concern of both Molina and Calderón is that the problem of water scarcity is exacerbated by climate change and the first signs are already showing.
“The issue of climate change is one of the concerns we have as ASADA. The spring that we had was enough to supply the entire community and now does not even give for 50 houses. We’ve really felt the decrease in the amount of liquid,” Calderón said.
What the ASADA directive perceives is backed by scientific evidence. According to the “Analysis of vulnerability of the oceanic and marine-coastal zones of Costa Rica to climate change”, technical series 06 of the BIOMARCC-SINAC-GIZ project (2013), Costa Rica has a high probability of decreasing annual precipitation in the coasts by at least 50% by the end of the century.
The scientists’ recommendation is to “reuse and recycle, especially rainwater, especially in areas where rainfall is expected to decrease or be sporadic.
Climate change cannot be avoided, but action can be taken to lessen its impacts and be better prepared to deal with its effects. This is called adaptation.
One adaptation measure is to promote a water culture focused on the rational use of water. According to the Food and Agriculture Organization of the United Nations (FAO), implementing savings actions on a regular basis can reduce the daily volume of liquid by 10% to 40%. This means that a family accustomed to consuming 20,000 litres of water could save between 2,000 and 8,000 litres by applying savings measures alone.
“The conservation and rational use of water is of vital importance. It applies to both neighbours and tourists who visit us,” said Calderón, who commented that the community has been concerned about preserving the forest cover around the springs and properties adjacent to them.
For Molina, another adaptation measure is precisely to collect rainwater to reduce the pressure on the communal aqueducts. In fact, this is one of the lines of action of the project “Bahia Ballena en Osa: construyendo puentes hacia el cambio climático” (Whale Bay in Osa: Building Bridges to Climate Change), which is being implemented by the Keto Foundation thanks to funding from the Adaptation Fund, whose administrative entity in Costa Rica is Fundecooperación.
Within the framework of this project, Keto Foundation is promoting improvements to the infrastructure of homes, hotels and other businesses through the placement of SCAPT. In fact, the architect Ariel Hidalgo Solano was in charge of the technical studies that allowed the design of three SCAPT models for Bahia Ballena.
Taking into account the hydro-meteorological data of the community, where there is an annual rainfall of 3,752 millimetres per square meter, a roof of 36 square meters can capture approximately 135 cubic meters of rainwater per year, that is 135,000 litres of water.
In this community, and according to Hidalgo, the average consumption of a family of four is 219 cubic meters of water per year (about 219,000 litres). The domestic activities with the largest water footprint are: the shower, with 80,640 litres; the flushing of toilets, with 80,640 litres; and laundry work, with 57,600 litres.
According to Hidalgo’s calculations, with a roof that measures 60 square meters, this family can collect 225 cubic meters a year (about 225,000 litres).
Through the project, the Keto Foundation funded three pilot projects in the community. The first was installed in the Bahía Azul hotel, owned by Calderón’s family. Instead of a tank, two were placed at a height of three meters from the ground to take advantage of gravity and gain pressure, in order to spend less time filling the washing machine and pool.
“With that rainwater we are washing the clothes and the sheets. Something curious is that we are seeing a decrease in the use of detergent. Once I was talking to a chemistry professional, he told me that the water in the pipe, having so much chlorine, needs more detergent to counteract the effect of this. On the other hand, rainwater, because it lacks chemicals, needs less detergent,” Calderon said.
Hotel Bahía Azul also uses rainwater to wash sidewalks and clean common areas, as well as an external shower near the pool.
According to Calderón, a “good and big rain” fills the two tanks and that liquid yields from four to five days depending on the use it is given. Future plans are to provide a system similar to the other two buildings that make up the hotel.
“ Yes, we noticed a 50% decrease in the water bill. Our biggest water footprint is in the laundry and in the swimming pool, so the system helped a lot in that sense. In addition, the guests like the initiative very much and many have taken the idea to implement it in their home. That’s very nice, because not only are we helping each other but we’re setting an example and it’s important that people see that you don’t need a big investment to make the change,” Calderón said.
The second pilot project was placed precisely in Guzman’s home. Observing the process at the hotel, Guzman suggested that Hidalgo replace the half inch diameter PVC pipe with one-inch pipes. With that, more pressure was gained.
Likewise, Guzmán’s accumulated experience allowed him to place the third pilot project in one of the residences of the rangers of the Whale Marine National Park.
Guzmán does not think twice: “Of course I would recommend to other neighbours to install a system of these. It is very simple and has a low investment cost. Although there is a good aqueduct in the community, sometimes there is a lack of water, especially during vacations due to the number of people who visit us. This system is a good option.”