In Puglia, as in many regions of southern Italy, there are long periods of summer drought which cause problems to agriculture. Thus ancient rainwater collection systems have always existed for both irrigation and civil use or for watering animals.
Until the last century first decades there was not water running in the houses and only noble palaces and farms had private rainwater collection reserved for the family.
Before the invention of irrigation techniques men exploited atmospheric humidity and water from the soil sediments: close to basins there were waterways and piles of stones to favor supply of water vapor; alluvial soils and dry courses of the ravines stored water reserves in the upper layers. These geographical areas became the habitat of the first Neolithic societies.
Catchment features
Aligned stones – capture the water released by the humid winds and the condensation that forms during the night
Harrah – stone dams used in Sabaean and Nabataean agricultural systems
Dams along the ravines – dams that block the underground flowing water along the ravines and drain the sediment water through channels that irrigate the terraces at the edges of the riverbed
Specchie – piles of limestone scattered across the countryside, generally conical in shape, which work as humidity condensers: as the night temperature drops, it gives rise to the phenomenon of condensation, allowing the accumulation of water. In the absence of a cave or a spring, the creation of the mound of stones allowed the protection of a water reserve from evaporation as well as the production of water through the condensation of dew.
Tu’ rat – crescent-shaped stone mounds. By taking advantage of the mists and humid winds of the Ionian coast, it is possible to grow plants and trees inside them due to the accumulation of rainwater.
Dry stone walls – used in agriculture to fence the fields. They also work as dew collectors. Thanks to large gaps among the stones capture the moisture-laden wind.
Surface cisterns in rock architecture – Cisterns carved into the limestone rock have been found in the Apulian territory since the Neolithic. They reached the maximum constructive complexity in the proto-medieval phase, with the development of the rock architecture of the Ionian-Matera arch. The distribution and use of water occurs according to a rigorous property division criterion.
A complex system of channels cut into the ground and along the limestone walls of valleys and ravines allows a large number of cisterns to be fed in series, arranged at different levels and often positioned inside caves. The caves were used as residences or workshops.
At the same time, rainwater was conducted into courtyards around which there were housing units that have the right to use this water reserve. The water was used cyclically, passing from more valuable uses to others, progressively less pure.
The pescare – underground piscine (pools). It is common to find them near the iazzi (ancient shelters for sheep and goats), farms or shallow erosive furrows which favored the flow of water towards the tanks.
They are characterized by a flat or sloping roof which usually hides a vault inside.
They are characterized by those architectural features:
– a roofing often at street level
– the collection basin
– a room made of stone or dug into the rock
– the supply channel to fill the chamber
– the drain channel for the overflow
– the settling tank used to make the water drinkable
– the well for drawing water.
The walls are made of limestone or dug directly into the rock and are usually coated inside with lime mortar to increase waterproofing and protect the building from the constant action of water.
The extrados of the pescare is usually walkable and made of limestone slabs.
Cisterns – architectural and landscape features arranged close to depressions in the ground, in the middle of agricultural fields or close to farms and various kinds of buildings to collect water from roofs and terraces.
A well for water extraction is connected directly with the cistern. Aside the wells there were often tanks for watering the livestock.
Underground ice house – thermal insulation is obtained through the wall mass and large volumes of earth which simulate the behavior of an underground structure. This typology is a hybrid between mound structures and more advanced tholos typologies.
Water harvesting in the masserie (farms) – Generally the first founding act of the settlement was the search of a significant water reserve around which, later, the community of the farm was developed.
The water problem was solved by collecting rainwater through a series of gutters which, set at different levels, convey it into the underground cisterns.
Water flowed in the cisterns also from the paved courtyards. The cisterns take on considerable dimensions and construction complexity and were characterized by the presence of a well.
The huge size of the cistern may have been determined by the exigence of surviving barricaded within the walls of the farm, in the event of an enemy attack.
Rainwater collection system in a field cultivated with citrus groves and vineyards. There was a drainage layer of the soil and a perimeter canalization to guarantee the simultaneous supply of the different levels of the agricultural terrace.
Final conclusions
In the lates 100 years we have lost this kind of knowledge of building which ensured to alter as little as possible the natural circulation of water at a local level, reuse precious water and prevent excess rainwater from leading to catastrophic events.
In many urbanized areas of our region the situation is so compromised that it requires comprehensive interventions to re-establish the lost water balance.
It is necessary that such a sage usage of natural resources inspire the planning and regulation of land uses and into the technical projects of settlements and infrastructures.
What we need now is:
- reducing surface runoffs;
- lighten the sewerage collectors and treatment plants;
- reduce the hydraulic loads concentrated on natural watercourses and reclamation canals, which constitute the terminal receptacles of the sewerage networks;
- increase local recharge of underground aquifers;
- improve the urban micro-climate by increasing evaporation;
- preserve and restore, as far as possible, the natural function of the soil
- prevent the formation of surface runoff from rainwater at a local level, reducing impervious surfaces or choosing permeable or semi-permeable forms of paving;
- implement measures for the use and/or percolation of rainwater, as close as possible to the place of formation;
- create local or central reservoirs to reduce flow rates.
Sustainable management must be extended to existing settlements and infrastructure and that certain choices must be shared and accepted by the property owners.
Their implementation requires attention not only to the technical aspects but also to the cultural and social ones.
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