Nine months since the National Green Tribunal (NGT)passed an interim order to stop use of underground water for construction in Noida and Greater Noida, it has taken cognizance of the violation of its orders against 12 developers. Sources reveal that this is just the tip of the iceberg and that if the Tribunal’s orders are properly implemented, work on more than 95% projects will come to a halt.
Dewatering a must for basements
Many architects are of the opinion that the Tribunal’s order to stop groundwater extraction during construction is inconsistent with the construction plan approved by the development authorities. No basement, especially in projects close to river beds, can be constructed without dewatering the foundation.
“If you are building a 20-storey structure, you have to dig at least four metres under the ground for a basement. If you go higher, you need to dig deeper. How can a developer construct an apartment in projects close to the riverbed without dewatering the foundation,” asks AK Jain, a well-known architect and developer who has recently launched a luxury project, The Jewels of Noida, in Sector 75.
Pile foundation is an expensive alternative
On there being a viable alternative to dewatering for basements, Jain says pile foundation is the only technique in civil engineering which can work, but the drawback is the high cost involved. “If a developer utilises this pile foundation technique for a high-rise, he will not need to dewater the foundation. The problem, however, is that the cost of laying the piles is one-and-a-half times more than the cost for basement construction. So the total cost of the project will go up and buyers will not be able to afford it,” says Jain.
It is also suggested that since raft and pile foundations (and sometimes a combination of both) decrease the possibility of water extraction, this should be made mandatory in areas where the water table is quite high. As far as the requirement of parking in buildings is concerned, it should be provided in the upper floors of the apartment.
Says Pradeep Kharbanda, an architect and town planner, “In India any one can misuse natural resources in the name of development to earn high profits. Why do we need to go for basements and why can’t we make provisions for multi-storey parking by building one or two towers (blocks) in project/townships which will take care of all the residents’ parking requirements? Unfortunately, developers will not like this as it will reduce the saleable area.”
“Some environmentally-conscious builders are taking precautions and are working towards logically dewatering through their own efforts,” says Kharbanda.
Amend construction plans
Many civil engineering experts hold the development authorities responsible for the violation of the NGT order. “First of all, the approval of building plans for any area should be assessed on the basis of its water table.
“No project should be approved in areas where construction permits interfere with the water table. The development authorities should keep this in mind while giving approvals to any project in future,” says a senior professor of civil engineering from IIT, Delhi.
He adds, “Now when a lot of projects have already been approved and are under construction, the development authorities should take up each project and assess whether they can be constructed in compliance with the NGT’s order.”
Inadequate water supply from STP
Another challenge in the implementation of the NGT order is the lack of adequate water supply from sewage treatment plants (STP) for construction. In its order delivered in January, 2013, the NGT prohibited developers to use underground water for construction purposes.
Though the concerned authorities claim to have enough STP water to fulfill every need, the developers dismiss it. “Most of the sewage treatment plants are defunct in Noida and Greater Noida. Those which are functional are unable to meet the huge water demand, so everyone is facing a difficult situation,” says Jain.
Many developers, who do not want to be named, admit that due to constant pressure by homebuyers to deliver projects on time, they cannot help but violate these norms.
“Authorities are unable to present the correct picture to the Tribunal. The industry is already under pressure due to several new developments. We are also accountable to homebuyers to deliver the project on time. The delay in delivery will invite penalty. Even if I get my building plan amended and adopt the combination of raft and piles foundation practice, how will I construct a building if I don’t get enough water supply from STPs,” asks a real estate developer.
International norms are against dewatering
Is dewatering for construction a common practice in other countries too? Experts say no. According to Rajesh Gulati, an NRI architect and one of the partners in DDG, an internationally renowned planning, architecture and design firm based in the US, developers should look for more innovative solutions instead of choosing the easiest way out – which is more often than not likely to be harmful for the environment.
“We have designed mixed- use projects across the globe, which are close to the ocean front/riverbeds with high water table. Building any basements in such spots is virtually impossible and definitely not practical. Diverse projects such as supermarkets, hotels, apartment towers and office buildings have been successfully accommodated in the same structure without resorting to a ‘dug-out basement’ concept,” says Gulati.
It is very common in the West to have an integrated approach to mixed-use planning. Typically, a structure incorporating parking entry ramps, lobbies of residential buildings/offices/hotels are all planned at the ground level. This practice is complex but highly successful and cost-effective, he adds.
Building experts say that there are quite a few places where height restrictions are in place, which necessitate underground construction. However, it is done with a lot of caution. “Authorities in some countries know that the cost to dewater and waterproof the basement is very high. The retaining walls too need to be designed to take water pressure from surrounding areas,” says an IIT Delhi professor from the civil engineering department.
For example, within the federal triangle area in Washington DC, no building can be higher than the Capitol Dome. Therefore, most builders have to pursue basement construction for parking. Also, there are areas close to airports where the height of buildings is restricted.