Shared rainwater harvesting heritage | Thirsty Cities

Many so called 'Small Island States', like the islands of the Dutch Caribbean, have always struggled with their fresh water supply. Surrounded by salt water with often little or mainly brackish groundwater its inhabitants needed to be very resourceful in securing water supply. In this rainwater harvesting played an important part. Due to their extreme vulnerability to the impact of climate change and natural distaster the UN has a special focus on increasing the resilience of Small Island States. In that light my Thirsty Cities research focuses on water supply heritage of the (former) Dutch territory in the Caribbean.

Ruin of a water cistern used to store rainwater in Oranjestad, Sint Eustatius (photographer: Saskia de Kock | source: RCE)

 

The last and only Sint Eustatius farmer told Dutch Newspaper Trouw in februari 2019 that he could supply the whole Island with fresh vegetables if he could store rainwater underground. Interestingly Sint Eustatius used to store a lot of it’s rainwater in cisterns. Unfortunately this knowledge and heritage has been largely forgotten. So it is high time to shed some light on the subject.

Drinking water and rainwater harvesting heritage

Rainfall varies greatly in the islands of the (former) Dutch Caribbean. Due to the tropical Monsoon on the ‘bovenwindse eilanden’ rainwater cisterns or ‘waterkelders’, ‘waterbakken’ and ‘regenbakken’ or ‘regenputten’ can be found scattered around the islands of Sint Maarten, Saba and Sint Eustatius. Aruba, Bonaire and Curacao (ABC islands) are semi arid with dry spells but may experience heavy rainfall during hurricane seasons, on these islands to a lesser degree smaller ‘regenbakken’ can be found.

The ABC islands used to be covered with dry tropical forests. Human activities from the first Amerindian settlers point to a slash and burn agriculture on a small scale. They used groundwater wells and potholes or waterkuilen to harvest rainwater.Some of these wells have been in use until this day but little is known about this subject and more research needs to be done to understand the pre-colonial watersupply system. An invaluable inventory has been made by an inhabitant of Curacao, Mary van Soest, of these so called ‘waterkuilen’, ‘karstputten’ and plantation wells.

Less rainfall due to deforestation

Deforestation on a huge scale in the ABC islands started with the export of brasilwood by the Dutch (from the 16th century) to Europe (for its red textile dye). Introduction of cattle to roam freely prevented the  green cover from recovering. Also mangrove forests along the coast were cleared. The last wave of large scale land clearing took place in the 20th century to make way for sisal and aloevera cultivation. The loss of green cover led to soil erosion and a different hydrological cycle and decreased rainfall. The erratic dry and wet spells are expected to become more frequent and extreme in the region due to climate change.

Ancient well or so called ‘karstput’ on the Noordkant of Curacao. (photographer: Mary van Soest | source: MOWIC)

Typologies of drinkwater supply heritage

The Rijksdienst voor Cultureel Erfgoed (RCE) made an inventory of its shared heritage in the Dutch Caribbean in 1995. From this inventory it seems most relics of rainwater cisterns can be found on Sint Eustatius. The cisterns to store rainwater were built on plantation complexes, near the port, military forts along the coast, churches and public and governmental buildings. Interestingly, the cisternes are not always built below the main building, as we are accustomed to in the Netherlands, but slightly elevated above ground level. They have more in common with Mediterranean cisterns than with the Dutch waterkelders. As the islands were first colonised by Spain this could be an explanation, but more research needs to be done on that part. Thanks to the rainwater cisterns Sint Eustatius could become an important trading port in de region.

To summarise the findings of my first exploration of drinking water en rainwater harvesting related heritage on the small island states of the Dutch Caribbean:

  • Larger cisterns like waterbakken and waterkelders can be mainly found on Sint Eustatius and to a lesser extend Sint Maarten
  • Smaller regenbakken and regenputten were important for domestic use and can be found through out the Dutch Caribbean, also on the semi-arid islands. On Saba rainwater harvesting in so called ‘tanki’s’ is still important for domestic use.
  • Surface water reservoirs also called ‘tankis’ or dammen where areas to collect rainwater en recharge the (karst-)putten. Earthen or stone walls were erected around it. Water was recharged through the ground or via natural or artificial wells. When sufficiently recharged, wind powered mills pumped up the water to open stone reservoir from where cattle could drink or water could be diverted to the fields and orchards.
  • Large ‘waterputten met pomp‘ with wind powered mills to yield water from deep below the surface. To catch enough wind they were erected on elevated structures and have become modest vertical landmarks
  • Ancient wells like karstputten, waterkuilen and plantageputten have been extensively inventoried on Curacao but more research on the subject is needed

Wind powered wells or waterputten in a ‘tanki’ surrounded by earthen dams to catch rainwater on Plantage Savonet 1890-1920 (Photographer: Soublette et Fils | source: Het Geheugen van Nederland)

 

Dwelling built in 1872 with regenbak to harvest rainwater from roofs for domestic use in Bonaire 1995 (photographer: Saskia de Kock | source: RCE)

 

Waterput with wind powered pump on Sint Eustatius in 1995 (photographer: Saskia de Kock | source: RCE)

 

Waterput or well with wind powered pump in Bonaire 1964 (Photographer: Boy Lawson | source: Het Geheugen van Nederland)