Pre-Hispanic Hydraulic System of the San Jorge River

Description

Municipality of San Marcos, Sucre N8 39 36.28 W75 7 48.15

Municipality of San Benito Abad, Sucre N8 55 45.37 W75 1 35.78

Municipality of Mompox, Bolívar N9 14 17.53 W74 25 29.01

The Hydraulic System of the San Jorge River occupies an area commonly known as Depresión Momposina (Momposina Depression) or La Mojana, where approximately 430.000 people live spread over eleven municipalities, of which nearly 80.000 live in rural areas and whose economic activity is based on fishing or agriculture, in a region with a relative humidity of 77% and an average temperature of 28.4 °C. This important ecosystem of the northern part of Colombia is made up by rainforests  and tropical dry forests, swamps, wetlands, rivers, canals in an area that covers approximately 500.000 hectares of the provinces of Bolívar, Córdoba and Sucre, at the junction of the rivers Cauca, Magdalena and San Jorge, three of the country´s main waterways. Therefore, this is an internal delta whose importance can be compared with Mato Grosso in Brazil or the Senegal River located in the Southern Sahara.

The Depresión Momposina is one of the largest flood zones in the American continent; it covers nearly 80% of the marshes of the Caribbean Region. The origin of its environmental conditions goes back at least 10.000 years, meaning that the inhabitants of the region had to adapt from the very beginning to the particular characteristics of the region. The geological nature of the region´s soils, separated from the sea by rocky formations from the Tertiary period and made up by lime and clay result in poor drainage, which combined with the high water tables that exist as a result of flooding, lead to a difficult evacuation of water from the soil. The area is located 25 under sea level and it has a history of soil subsidence, which consists in progressive sinking of a meter of soil each two hundred years as the result of the weight of sediments carried by the rivers and which are likely to have destroyed archaeological evidence. Most of the Hydraulic System is found along San Jorge River and the channels of Mojana, Panseguita and Rabón which cross the Depression.

Archaeological research, which is concentrated specially in the area located to the southern part of the Municipality of San Marcos (province of Sucre), indicates an occupation of the zone between the X BC and XII AC , divided in turn in two non contemporary periods which are related to two different human groups. The oldest occupation moment corresponds to the development of ridges and drainage systems, terraces for housing and burial mounds where gold and ceramic pieces have been found. However, the region´s height was between the 5th and 10th century AC.

The contribution of silt derived from periodical flooding makes this a very fertile zone, a quality that was well used by the first inhabitants and by the Zenú indigenous people to establish terraces and ridges of approximately three meters high to move the waters. These structures were built progressively and used to dominate an extensive area with great environmental contrasts where the dry season would only last four months (November to March) making them spend the remaining of the year between extensive marshes and flooded plains.

The terrace and ridges system they had developed enabled the generation of a model of sustainable use of the land which we have also seen in other places and countries such as Bolivia, Ecuador, Mexico, Peru and Venezuela (to cite only countries in the area. The San Jorge system being the largest in the continent) which shows that although a high initial investment is required in terms of work to prepare agricultural terraces and housing, such investment is later compensated with minimum maintenance and high rates of agricultural productivity by maintaining the required moist levels throughout the year.

The ridges and channels network is built in marshes and rivers and covers extensions that may reach four kilometers long with an average of ten meters wide. They form patters varying from those that run perpendicular to the rivers and those that have a fish bone like shape (located in internal meanders of the rivers), there are others that are fan-shaped (located in the external meanders of the rivers) or chess game shaped (located in the outer part of the marshes). After extensive archaeological research, it was evidenced that these networks were part of an extensive drainage system designed according to the dynamics of the bodies of water and the geomorphological conditions of the site.

Thorough examination of the Hydraulic System has led to conclude that the existence of channels that run from the outer part of the Depression (Caños Carate, La Pita and Rabón), both in the eastern and western side, allowed for the evacuation of waters from the intermediate zone, which was then fitted to house the inhabitants´housing and crops being always protected from major flooding.

The Zenú civilization was divided into three groups, strategically located in the region. The Cenufana Group was located in the southern zone and was specialized in the extraction of raw materials; the Fincenú Group lived in the Sinú River basin and was specialized in the elaboration of gold and silver work, while the Pancenú Group was located in the San Jorge River lower area, where the largest remains of ridges have been found evidencing their agricultural and fishing vocation. One estimates that during the maximum agricultural exploitation period of the zone, a population density of up to 180 inhabitants per square kilometer was reached whereas currently there is hardly one resident in the same proportion.

At present, some towns, such as San Andrés de Sotavento (province of Córdoba) preserve the footprints of the settlement patterns of the first inhabitants of this area.

The housing platforms cover areas ranging from 4.000 m2 (in the case of the detached houses) up to 200.000 m2 (where evidence of small villages housing up to 600 people has been found) with a linear settlement pattern. In the outer areas, cotter elevations have been found with heights varying from two to six meters used as burial sites. garbage was not disposed of in the channels, instead it would be deposited on the terraces in places that would not hinder access to the house; several ceramic samples have been revered from these sites. Similarly, the presence of domestic vegetable gardens has been detected on the shortest ridges, located near those ridges occupied by housing. Today, although various trees have grown in the fertile terraces, the latter preserve the residential use and one presumes that some current buildings preserve features of the original pre-Hispanic houses such as the rectangular plate, mud walls, palm leave roof, the round timber structure and the spatial division of activities such as cooking, sleeping or socializing in average areas of 2600 m2 for each one, between covered and open areas.

The ceramic remains found in the area correspond to three groups: the first one made up by a group of artifacts consisting of globular cooking pots, glasses and bottles with zoned incisions and prints as decoration, while the second group shows a light colored ceramic and decorations with “shaped motifs and geometrical designs in red paint”. A third group is made up by sober-shaped artifacts with fine incision decorations, where there is no difference between daily use artifacts and funerary artifacts; this type of ceramic was used during the XIII and XIV centuries AC and it determines different cultural patterns as burials would take place inside the houses and at times the human remains would be deposited in funeral urns.

Goldsmithing, in turn had been developing from the 2nd century BC, reaching its height towards the 5th century AC, and it would be connected to the religious life of the communities residing in the area. The Zenú People reached a high level of purifying in gold transforming techniques. Gold was found in abundance in the southern part of the Depresión Momposina, in Córdoba and Antioquia.

Among the crops identified in the area where archaeological excavations have taken place we have pumpkin, peppers, sweet potatoes, squash, coca leave, corn, passion fruit, nolí and cassava and in general easy reproduction plants with a high level of resistance to plagues. Small vegetable gardens would be combined with large extension crops, especially roots, constantly using fertilizers based on the sediments that would be moved periodically and by hand from the lower to the upper part of the ridge. Similarly, evidence has been found of intensive fishing exploitation of numerous species that would contribute proteins to people´s diet at the same time taking advantage of the upstream fish migration.

After more than one thousand years of Zenú occupation, towards the 14th century, the area was occupied by the malibúes group who did not expand the ridges system. After the Spanish Conquest, one observes the progressive abandonment of the area by the malibúes and the introduction of livestock farming, leading to an important reduction of vegetation reaching a minimum level of 6% during the XVIII and XIX centuries.

Justification of Outstanding Universal Value

The crop and housing terraces and ridges system located to the western part of the area known as Depresión Momposina or La Mojana, was an alternative adaptation to the surrounding environment used by the indigenous communities that occupied this flood area of the continent over a period of more than two thousand years leaving numerous archaeological remains made up by samples of ceramics, gold smithing and in general by evidence of their daily activities. Due to its extension, this is the largest transformation undertaken by pre-Hispanic man in the continent.

Many of these structures are preserved today in spite of the advancement of livestock activities and they are a real and feasible alternative to improve the life conditions of the current residents, who continuously suffer material losses caused by flooding that occurs periodically in the area within a natural cycle which until today has not been understood and used adequately.

Criterion (iii): Although this type of drainage system was also used in other flood areas of the continent such as Bolivia, Mexico, Ecuador or Peru, the drainage system of the San Jorge River is the largest of South America, becoming the most important example of landscape transformation carried out by a human group in this area of the world.

Criterion (iv): The hydraulic system is a work of Pre-Hispanic engineering of large extension whose construction saw the use of rudimentary tools combined with mathematic calculation of great precision which transformed a large percentage of the northern part of Colombia and that was used continuously during two thousand years. It’s a system that can be use today.

Criterion (v): This land occupation model was extensively used in America and it is characteristic of amphibian communities that find in this type of system, a way to interact with the environment.

Statements of authenticity and/or integrity

In spite of the abandonment of destruction of part of the terraces and ridges due to the expansion of the agricultural and livestock borders, an important percentage of the structures have remained standing until today and can be used as a sustainable development alternative. Some of the spatial characteristics of Zenú´s indigenous houses are found in the current residents´ homes, which show the continuity in the building tradition of the region. A good part of the archaeological evidence found in the Depresión Momposina is still under the custody of the Gold Museum and can be seen by the public, in addition to being protected as cultural heritage by the legislation.

The Pre-Hispanic Hydraulic System of San Jorge River stands out due to its being the largest transformation made by Pre-Hispanic man in their territory, an effort that has no comparison in this part of the world. This is an efficient system that uses the site´s environmental conditions and although it entailed huge initial efforts in the number of cubic meters removed and hand labor and tools used, they were later compensated by sporadic maintenance works and high levels of productivity. Moreover, this is an infrastructure that can be re-used as a real and sustainable economic alternative for those currently living the Depresión Momposina.

Comparison with other similar properties

Chaco Culture (United States)

The park is inscribed on the World Heritage List under criterion iii, the Chaco Anasazi culture located in the south western part of the United States in the Chaco Canyon not only left exceptional architectural remains represented in public ceremonial buildings but it also developed between the I and IV centuries BC an extensive irrigation system handled by gates that moved the water between the Salado River and its crop growing areas located in far and dry zones.

Historical Center of Mexico and Xochimilco (Mexico)

The Center is inscribed on the World Heritage List under criteria number ii, iii, iv y v. Xochimilco is located 28 kilometers to the south of the city of Mexico and is made up by a network of channels and artificial islands built by the Aztecs; it remains as the testimony of the occupation of an originally lacustrine territory that was dried after the arrival of the Spaniards and on which the current city of Mexico was founded.