A Zonal Storage water supply system with Hydraulic Isolation Structures and a method thereof.
Conventional water supply is designed for continuous water supply; hence, they are not suitable in the Indian context where intermittent water supply is prevalent. At times, the water tanks are bypassed. Moreover, problems are faced such as unequal water distribution to the consumers, differential pressures in upstream and tail end of service area, and inadequate pressure at receiving end in households.
Water supply methods and pressure management technologies proposed by prevalent practitioners and consultants are not ideal for the Indian context because they are designed assuming uninterrupted water supply with operation and maintenance practices followed in developed.
An innovation in the form of a Zonal Storage with a Hydraulic Isolation Structure (ZS-HIS), which has been tested successfully in settlements of different scales.
In India, the elevated storage reservoir is often constructed outside the residential area it serves, which is not ideal. Additionally, the expansion of the distribution network in response to unplanned development and construction of multi-story buildings within existing areas is not well-controlled as the city grows. Moreover, the population of the zones served by the storage tank fluctuates, and with the current methods, it is difficult to estimate the exact growth.
In this rapidly changing and evolving context, the existing water distribution system cannot deliver water as it lacks the required flexibility and adaptability. This demands a system that can respond to dynamically changing water supply needs. Additionally, there are several situations where pressure needs to be reduced due to topography or local conditions. The uncontrolled withdrawal from the pipes needs to be restricted. Currently, methods and tools which are based on practices that work in developed countries are in use, which are unsuitable for the Indian context and hence there is need for innovative solutions.
The benefits of the ZS-HIS based distribution systems are many, some of which are highlighted below.
- ZS-HIS can be constructed at a much lower cost and needs significantly less land than ESR, resulting in significant cost savings.
- ZS-HIS can reduce the supply hours resulting reduction in energy bills and increasing sustainability.
- ZS-HIS can achieve equitable distribution as the shaft can be constructed at the center of habitation and can have multiple outlets.
- ZS-HIS is simple and easy to implement and can be locally fabricated or constructed.
The benefits of the ZS-HIS based distribution systems are many, some of which are highlighted below.
- ZS-HIS can be constructed at a much lower cost and needs significantly less land than ESR, resulting in significant cost savings.
- ZS-HIS can reduce the supply hours resulting reduction in energy bills and increasing sustainability.
- ZS-HIS can achieve equitable distribution as the shaft can be constructed at the center of habitation and can have multiple outlets.
- ZS-HIS is simple and easy to implement and can be locally fabricated or constructed.
ZS-HIS technology can achieve a more efficient design and tackle the operational problems discussed above, and it will eliminate/limit local interferences affecting water distribution. As shown in Figure , the ZS-HIS system is a unique layout of the Water Distribution Network (WDN) where present storage tanks can be treated as zonal storages. The main water distribution lines can be fed to shafts with multiple outlets to carry forward the available pressure closer to the consumer without significant hydraulic loss. The shaft creates a smaller umbrella influence zone and takes care of equity within the overall influence zone of the main storage. It automatically negotiates undulations and related reduction of pressure levels. The ZS-HIS helps overcome the shortcomings of the large centralized approach and can provide a solution through a decentralized infrastructure approach in both existing and new WSSs. In order to achieve equitable distribution, the ideal location of the shafts with multiple outlets in the ZS-HIS should be such that the shaft is placed at the center of the serving sub-zone. This is possible even in densely built-up Indian cities as the shafts with multiple outlets requires only a small area (about 10 m2) for installation.
In addition, the shaft as part of the ZS-HIS serves as a hydraulic barrier between the actual consumption point and the Elevated Storage Reservoir (ESR). As consumers receive water from the shaft of the ZS-HIS instead of direct tapping from distribution mains, there is an improvement in the overall hydraulics and, ultimately, the system’s performance. The pressure in ZS-HIS is automatically stabilized based on the downstream withdrawal, minimizing the need for several valve operations. As the ZS-HIS serves water to consumers reliably with appropriate pressure, consumer satisfaction is achieved.
This system ensures a continuous 24/7 water supply by stabilizing the hydraulic grade line (HGL) based on downstream demand, reducing consumers' need for excessive water storage. By providing equitable water distribution, the system helps control the overconsumption of water typically seen during intermittent supply hours. Also, it mitigates the operational complexities and maintenance challenges associated with excessive valve operations in traditional systems, enhancing overall efficiency. Consistent water availability and efficient distribution can also relieve the overcrowding of cities, as a reliable water supply supports balanced urban growth and reduces the strain on urban infrastructure.