Landscape Elements refer to the variety of artefacts found in the landscape. One such landscape element is a pond. In the larger general landscape, water bodies refer to all forms of water seen on the earth’s surface. These include rivers, streams, waterfalls, lakes of many types and ponded water. In Sri Lanka, these large bodies of ponded water are called ‘vila’ or ‘villu’ occurring naturally mostly in the North-Western and North-Central Provinces. The ‘Region of Ponds’ is Wilpattu. Ponds occur in a shallow depression in the ground, are rain-fed, often vegetated and not connected to any other type of body of water. They should not be confused with the wewa, the connected reservoirs of our irrigation system.
In a garden a pond is similar but often an artificial construct. A good design may locate the pond at the lowest level within the site. Natural ponds may occur on large sites. The topography or landform will naturally allow drainage towards the pond. This type would sit comfortably on the land, take the existing contours and appear natural.
Other ponds may be located due to the functional needs of the site and not necessarily follow the landform. The water will have to be artificially constrained so as not to allow it to ‘escape’ as drainage. These are often reservoirs or tanks located in close proximity to requirement as a stored source of water supply. Supply may be made by gravity feed or pumped depending on the pressure head required.
Historically, Anuradhapura is host to the Twin Ponds (Kuttam pokuna) for use of Royalty and the Lotus pond among many others. These were cleverly constructed functional pools used for bathing with seating elements, steps and edges aesthetically articulated. The Ranmasu Uyana, is shown to have had showers and a terraced arrangement of pools each different in outlook according to functional need. This was possible due to the landform and the pressure head of water available as the supply was from the Tissa reservoir (wewa) at the highest level allowing for gravity flow.
Many other ponds were appurtenant to the dwelling place of the bhikkus (aranya, or aramaya) and the hot baths (jantaghara). Often, the dagaba (chaitya) when situated on high rock formations overlooking the landscape, had an adjacent rock pool. These can be seen at Maligatenne in Gampaha, Thiriyaya, Eastern Province, or Colombo at Balapokuna Raja Maha viharaya. This was a rain-fed catchment of water in a depression in the impermeable rock and was adorned with lotuses or nymphaea spp. With water skaters, a tiny insect, skimming the surface and darting between leaf stalks. At Balapokuna, the pokuna (pond) is under threat of possible fracturing of the rock thus draining the water due to roadworks.
Famously, Sigiriya Rock abounds in ponds of great variety from the highest level on top of the rock to the gardens on the plain below, the ‘Water Gardens’ of varying scales. Discussion of these will require a treatise by itself and much is already recorded.
Ponds or Pools
The words pond and pool are often used interchangeably but differentiated in that the appearance of a pond is very much different to a modern swimming pool. Ponds are more nature-based while modern pools will have tiled surfaces and water treatment equipment. The swimming pool is not considered in this article.
The choice to have a pond in a garden should stem from function or the topography. It is unnatural to have a pond on a sloping or flat site which is not subject to water-logging or the collection of water on such a site. However, the slowing down or moderation of water flow has been cleverly exploited in such terrains by design and the inclusion of ponds at intermediate levels. The early English gardens of William Kent (1685 – 1748), the Japanese and Chinese traditions, the delightful waterworks of the Italian Renaissance gardens of Villa D’Este and Villa Lanté and our own cascade system of wewas (elango system) are a series of connected ponds. Varied functions may be attributed. As a sensory attribute ponds may visually reflect its surroundings or be a focus for contemplation and mental reflection. As an environmental attribute cascade systems may be used for water purification, sediment traps and other physical functions. Both promote health and well-being for individuals and communities.
Formal or naturalistic
Returning to ponds in parks and gardens, they may be formal or naturalistic. The formal pond would often be of geometric form with a clearly seen edge, either plain or decorative. Formality would demand attention and likely be on an axial layout. Formal ponds are linked with the culture or style of a particular landscape. Roman styles, Moorish or Persian styles may dictate shape and proportion. Cultural inflections may require golden carp swimming in a pond in China, while Italy may encourage coins being thrown into the pond. The very linear narrow formal pond in Washington D.C. is meant to reflect the Washington Monument in its still water when observed from the Lincoln Memorial over a kilometer distant. While common in the Mediaeval periods to be a feature or reflective, the current trend is to respect nature and natural forms.
Natural or naturalistic ponds are a delight, and host to vegetation and fauna. The form of the pond would be organic shaped with gently curved edges, following the natural topography. As a pond has still water the bottom may have silts and other sediments with rooted plants. It is unlikely to have a base of pebbles or stones as found in flowing streams. Even rock pools have a monolithic continuous surface rather than small components. The vegetation around a pond would allow it to bind to the general landscape, with perhaps a low ground cover or grassy edge on visually seen or accessible edge and a backdrop of plants in keeping with the locale. The main fauna in a pond would be a variety of fish with pond snails, water skaters and perhaps frogs (if allowed). Kingfishers and egrets may benefit with an occasional meal of fish. A large pond, especially close to marsh areas may attract water monitors (Varanus salvator).
The dynamic nature of a naturalistic pond contrasts strongly with the static, imposing elegance of a formally designed pond.
Technical Applications for Ponds
Whatever the design the technical aspects are imperative. The pond must essentially be impervious to hold the water and not allow for leakage, the edges require careful choice in scale to make the water surface visible. The choice of materials, textures and colours in keeping with the other elements in the vicinity and the scale proportionate to the overall visual scene. Rain gardens must necessarily have a balance between the ponded water and the adjacent seasonally drier areas, allowing for increased ponding during wet seasons. The areas where water is always found being the retention area. The detention area allows for access and use during dry seasons which during wet seasons is covered by water taking up flood water and temporarily increasing the size of the pond. This changing scenario has an influence on the vegetation and fauna.
Whether natural or formal, either type requires the appropriate landscape management. Water quality is monitored for clarity, colour and unwanted material. Surfaces may require periodic scrubbing depending on the material. Siltation may result in reduced depth which may affect fauna. Even drastic measures such as de-watering and re-stocking may be required. A good landscape manager will know when to leave the decaying log on the water’s edge and where to be pristine and neat.
Plantsmanship is an important factor. Some formal ponds may be devoid of planting, others may have containerised plants near the surrounds, formally positioned lending a Mediterranean style. The naturalistic ponds require more attention to the choice, compatibility and arrangement. Water plants, edge plants, usually rushes or grass, herbaceous plants in the near areas harmonize a pond with its surroundings and perhaps shrubs or canopied trees give structure and shade. Ponds in landscapes worldwide show great variation whether vernal pools in USA or a billabong at the bottom of a meadow in dry Australia. In temperate zone countries springtime snow melt and minor flooding cause ephemeral pools to form. The number of trees and placement matters when binding these to the landscape. A small copse of trees or a single majestic one spreading its branches over the pond may stand back from the margin, while in our very Sri Lankan landscapes, shady groves of Kumbuk trees (Terminalia arjuna) would dabble their purifying roots at the water’s edge.
Skilled professionals would carry out an assessment and through a design process decide on the requirement for a design element such as a pond. Perhaps there are existing ponds on the site or potential for such. The most appropriate outcome would be an asset in the hands of an expert and proficient landscape professional.