As the site falls under Costal Regulation Zone I, according to the CRZ norms, 200m from the beach is to be a No Development Zone. There shall be no new constructions in this zone. Pumping of ground water is also prohibited in this zone. Almost 65% of the site falls under this zone. There were 3-4 existing shallow wells in the region but unable to yield the water to required quantity and Gokarna does not have any centralized water supply network.

The only other source is water supplied by private tanker lorries; but this, besides being extremely expensive, is also untreated water with uncertain quality.

After considering the various options, M/s ‘Inspiration' recommended that the best option would be to integrate the concept of Total on site water management for the project at the design stage itself: which would focus on

Detailed cost estimates for each of the above items were taken. In comparison to a reservoir with ferrocement or RCC lining, the cost for the lake at Swa swara claims the following significant merits.

Construction of the Lake
The construction of the lake was started in April 2004. The bulk of the excavation was done with the help of four JCB excavators. The final leveling and shaping of the lake was done manually.

The entire excavation was completed in 45 days. This was followed by laying the underdrainage network on the northern side and base of the lake. The underdrainage consisted of perforated corrugated flexible HDPE pipes wrapped in non woven polypropylene filter fabric. After laying the under drainage network, a 50mm thick sand layer was provided on the sides and base of the lake.

This was followed by laying of the 1 st layer of liner fabric in Lake 1 – the 150 micron LDPE liner. By this time, we were overtaken by the monsoons which arrived almost two to three weeks ahead of normal. To protect the liner laid in Lake 1, it was covered with a layer of sacrificial fabric – slit tape HDPE. With this, we could harvest rain water during the monsoons in Lake 1 and use it for construction and other uses in the site. This helped us save almost two to three lakh liters of water used for construction.

After the monsoons, we resumed work on Lake 2. This involved reshaping of some of the sides which got damaged during monsoons. This was followed by laying of the two layers of liner fabrics. The 150 micron LDPE was given cold seal joints with bituminous sealants. The 300 micron fabric was given heat sealed joints. After the two layers of liners were laid, the base of the lake was given a layer of 100mm sand. Along the base, laterite masonry toe wall was built. The sides of the lake was then pitched with random laterite masonry in a lean cement mortar.

Subsurface filter drains
The rain water falling on the roofs as well as the surface run-off from the site is channelised to the lake for recharging it. The conventional storm water drains for surface drainage, besides being expensive; need recurring cleaning and maintenance for satisfactory performance.

To overcome this limitation, it was decided to opt for sub-surface drains. Subsurface drains, when properly designed and constructed need no maintenance and are also capable of draining the soil mass below ground in general. This would prevent water logging.

Considering the catchment area and quantity of water to be drained off, a network of filter drains of various sections have been provide as per drawings attached.

A typical sub surface filter drain consists of a trench lined with non woven polypropylene fabric, filled with graded filter media having a perforated drainage pipe inside. After wrapping the media with PP fabric, the top part of the trench is filled with coarse sand and random laterite. The top surface is finished with a layer of rounded pebbles and where the drains cross vehicular roads, dry open jointed laterite pitching is provided.

To tap rain water from the` larger catchment outside the site, which has the natural drainage through the site, drainage trenches were dug along the compound wall to guide the drainage, then chanelised through a rain water filter and diverted to the lake. The rain water filter has an overflow system which ensures that during very heavy rains, the excess flows out of the site causing no unplanned scouring/ erosions.

The lake ecosystem
The lake has been developed as close to a natural ecosystem as is possible. There is very restricted activity in the lake. While swimming is totally avoided, passive recreation like boating on small coracles can be tried.

Controlled aquaculture with grass carp takes care of the algae control; to ensure that the fish feed on the algae, feeding of fishes by guests / staff is to be totally discouraged.

Purification of water from the lake
The purification system for the harvested rain water consists of a simple pressure sand filtration, activated carbon filtration and chlorination for disinfection.

Treatment and disposal of sewage
In order to optimise the usage of water, the black and grey water (sewage and sullage water from kitchens and bathrooms) is treated and reused for gardening and other non-potable end uses.

Since there is open land available on the site, the main criteria for selection of the system for treatment and recycling of waste water were

The system adopted is known as the DEWATS approach (Decentralised Waste water Treatment System). The black water and grey water from the cottages and various blocks are collected in settler tanks. The primary treatment takes place in these settlers.

Within the settler, two main treatment processes take place. First, a mechanical treatment retains contaminants by sedimentation/ floatation and the waste water from the clarified layer flows through the outlet. Second, through biological treatment, the remaining organic pollutants are partly decomposed by micro-organisms. Through the digestion process the accumulated sludge is stabilized. Storage volume for sludge is provided for 18 – 24 months desludging interval. Average reduction of BOD in the settler is expected to be between 20 and 25 %.

For the Kitchen and the Ayurveda Block, oil separators have been installed prior to the Settler to remove excess of oil from the waste water. The collected waste oil is mixed with other bio degradable solid wastes and fed to the bio gas plant installed.