The polders in Suriname

With an area of 16.4 million hectares, Suriname is the smallest country in South America. In 2024, it had a population of 630,000. The country has a very warm and humid tropical climate, with temperatures ranging from 29 to 34 °C. There are two wet seasons, from April to August and from November to February, and two dry seasons, from August to November and from February to April.

Like its neighbours, Suriname has a relatively flat coastal plain, approximately 120 kilometres wide in the West and 40 kilometres in the East. The fertile clay soils, its location near rivers with ample, high-quality water, and the absence of storms and natural disasters made the coastal plain, among other things, very suitable for rice cultivation. However, there were also unfavourable conditions: the inaccessible mud coast, moisty swamps with many mosquitoes, a high risk of disease, salt water intrusion, an unstable coast, and soft clay soils.

In Suriname, too, as I described in the Guyanas, raised fields and mounds were originally constructed. However, after Dutch colonization, thousands of hectares have been reclaimed since 1675, considerably more than in the other Guyanas. Part of this area was reclaimed by slave labourers. For example, in 1668, there were 23 sugarcane plantations, and by 1800, there were 641 plantations along the Para River and the downstream sections of the Suriname and Commewijne rivers. Hundreds of hectares of polders were also developed along the Cottica River.

Ehrenburg and Meyer described how the first polders were constructed for the cultivation of expensive tropical crops such as sugarcane, coffee and cotton. Especially in the western Nickerie District, the polders housed not only rice but also banana plantations. These plantation polders had an advanced and multifunctional water management system. They were therefore considered a model for polder construction in the neighbouring countries.

As early as 1787, agriculturalist Anthony Blom described how plantation polders were constructed. During the dry season, the land where the dike was to be built was first cleared. Then, a clay dike was constructed, along with a surrounding ditch. Blom also noted that peat could not be used for the dike. Subsequently, the land within the polder was reclaimed, raised fields and ditches were made, and a culvert for the discharge was installed at a suitable location in the dike.

In line with Blom's description, Ehrenburg and Meyer, as well as Da Costa, provided detailed descriptions of the plantation polder infrastructure. They also described the steps involved in the construction phase, which lasted at least four years. Most plantations covered an area of between 215 and 430 hectares. Within the plots, approximately 0.90 metres deep ditches were dug at 6 metres intervals, creating a domed system of fields. Each plot contained 100-150 beds, and adjacent to each 6-9 hectare plot was a clay road or dike, which could only be used during the dry season. In addition along the edge of each plot a ditch was made.

Excess water was discharged via ditches and submain canals to a main canal, from where it could be discharged via a sluice - often combined with a pumping station - and a regional canal, from which, at low tide, the excess water could be discharged via a discharge sluice to a tidal river. Fresh water was supplied from the upstream marshes by gravity. From the beginning until the 20^th century, the polders were constructed manually. In the 20^th century, mechanization was introduced. Based on a water balance calculation for rice fields in the Wageningen polder, Kamerlingh determined a required discharge capacity of 20 millimetres per day.

The Group Polder Development of Delft University of Technology mentioned the following polders in Suriname:

• in the Western District of Nickerie near Jaricaba, two polders of 450 and 550 hectares;
• in Northwest Suriname, a polder area of approximately 10,000 hectares in 1950 grew to over 40,000 hectares in the early 1980s;
• since the 1980s, the polder area in Nickerie has expanded to 57,000 hectares, involving the following projects:
• Nanni Polder 9,000 hectares;
• Coronie Polder 2,000 hectares;
• Multifunctional Corantijn Project 33,000 hectares.