Principal C.E-cum-Secretary,
Water Security & PHE Deptt.,
Government of Sikkim, Gangtok

Minister,
Water Security & PHE Deptt.,
Government of Sikkim, Gangtok

(a) To provide safe and sufficient water for all the consumers.
(b) Developing strategies to meet the increasing demand for water & Sewerage system.
(c) To ensure effective service and timely realization of revenue.
(d) Developing customer’s services and delivery systems so as to collect the revenue and make efforts to see that the system is sustainable in future.
(e) Take into account suitable strategies and adopt suitable means to consider the environmental concerns thereby avoiding environmental degradation and pollution mainly while disposing the treated waste.

a. Construction and maintenance of Water Supply, Sewerage and Sanitation facilities in the Urban Towns, selected (Semi-Urban towns) Bazaars and their peripheral rural areas.
b. Formulate and implement Sewerage services and Water supply tariff.
c. While implementing various development schemes, ensure that the water sheds, sources of water supply and environment as a whole are properly conserved.

The Department is headed by the Principal Chief Engineer Cum Secretary, assisted by one Additional Chief Engineer and two Superintending Engineers. There are 4 Divisions and 7 Sub-Divisions for executing various project works. They are also responsible for Operation and maintenance of completed Schemes. An Organization chart of the Department is as follows:-

WATER SUPPLY SYSTEM IN THE STATE – (UNDERSTANDING OF WATER SUPPLY SYSTEMS OF HILLY ARES AND ITS ECO-SYSTEM)

a. Tapping of water sources located at higher ridges.

b. Transporting the same (raw water) through gravity mains from the source to the lower reaches, treatment to render it harmless and potable, storage and finally distribution to consumer points through Zonal Distribution Systems.

c. Spring flows from the water reserved in the underground bowels of rocks. These bowels in the rock strata have to be charged with rain water. Charging takes place only if there is vegetation, otherwise ground will not soak water and the water will quickly flow down the valley and be lost.

d. Surface water sources are very sensitive to pollution and degradation of environment. In the state at many places these sources are drying up. South and West districts of the state are comparatively dry areas. It is noticed that snowline at Bermeli source for Namchi is gradually receding causing reduced discharge.

e. PHED has been successfully supplying water to all its consumers, however, there still exists scope for improvements in the present system for which a forward Planning and implementation of well carved policy based programs is essential to obviate any unforeseen future catastrophe of water shortage in the state.

WATER SUPPLY, SEWERAGE AND SANITATION SYSTEMS OF THE FOLLOWING UNBAN, SEMI-URBAN AND RURAL CENTRES ARE UNDER THE PHE DEPARTMENT :

Gangtok is the capital of the state with population of approximately 125,000-150,000 consumers.

Glacial fed Lake Tamze (altitude 12,500 ft.) is the source of Gangtok water supply. Ratey Chu rivulet emerges from this lake which is tapped at about 5000 ft. downstream (altitude of 8200 ft.).

From this Tapping Point or Water Supply Head Work (altitude 6800 ft.) 36.36 million liters (theoretically) of water is transported to a distance of 17 Kms to Selep Water Treatment Plant site through 3 numbers of 6” dia, one number of 8” dia and one number of 14” dia Raw Water Trunk mains.

Selep water treatment plant presently has treatment capacity of only 36 MLD daily. Expansion of treatment facilities to accommodate the entire volume of 36.36 million litres of raw water is being presently taken up at the cost of Rs. 500.00 Lakhs. This work has been completed.

Treated water is reserved in the reservoirs of 45.45 million liters capacity at Selep. From here, water is transported to over 20 nos. of Zonal Reservoirs and thereafter distributed to the consumers through the network of over 150 Kms of Trunk lines, feeder mains and distribution lines.

Existing demand of water is estimated at 27.00 million liters per day, therefore, presently quantum of water being brought from the source is sufficient, however. There is a pressing need to increase the capacity of many raw water mains within the consumer areas to remove the bottleneck and to facilitate transportation of water to various water deficient areas.

Due to existing shortcoming in the system, the Department have to resort to Intermittent System of supply of water. Water demand for year 2001 and beyond is estimated to be approx. 40.90 MLD, therefore, presently available water of 36 MLD shall not be adequate and hence, there is a necessity to further augment the supply.

Gangtok is the only town of its category to have full fledged sewerage system. Of the three phased Gangtok sewerage scheme, first phase was implemented during 1979-80. The system today caters to approx 45,000 people. Gangtok town sewerage system stands timely implemented and has been an immense help for the community. It is also helping to keep river Rongni Chu from being excessively polluted.

The main trunk line is 30” in diameter which has been laid along NH31 A from the center of town to treatment plant site at Adampul and covers a distance of almost 12 km. The town’s Sewerage system consists of collection of domestic sewage from various zones through collections chambers and Submains (6’’ dia to 9” dia). Submains are connected to (12” dia to 24” dia). Sewage is finally transported through trunk line (30’’ dia) to Adampul treatment plant site. Sewage influent is treated here to render it harmless and finally disposed off in to the river body.

Initially over 33,000 ft. of pipe lines had been led to cater to the central business district (New Market, Old Market, Kazi Road and Tibet Road areas), and since then many other developed areas have been included in the system, namely, Development area, GICI area, Diesel Power House area, Arithang area, Church Road area, parts of Sichey area, etc.

Sewage treatment plant is well maintained. It consists of primary treatment unit (Grit Chambers and Primary Sedimentation tanks); Secondary Treatment Units, e.g. Bio Filters and Tertiary Treatment Units (Clarifiers). Solid waste is treated through the Sludge Digester.

The plant has one good Laboratory which monitors that the effluent is treated to acceptable standard before the same is disposed off into the river body. The lab also monitors the health of river Rongni Chu.

Expansion of Sewer System is continuing in more and more developing areas. Considering the expansion, besides the 1.26 M.G.D. T.P., additional T.P. of 1.76 MGD Capacity is being installed to take up the additional load owing to expansion and extension of sewerage network.

Apart from Gangtok town, Water Supply in eight other notified urban towns including three District Administration Centres are looked after by the Water Security & Public Health Engineering Department. These towns are growing rapidly as tourists as well as commercial centers. Namchi, Pelling, Ravangla, Yuksom today attract large number of tourists. Therefore, there is a need for augmentation of Water Supply Systems of these towns.

While all the eight notified towns have been covered by proper water supply systems, of the seven towns, treatment facilities are available in Namchi, Rangpo, Jorethang, Singtam and Mangan only. Therefore construction of Water Treatment Plant with Filtration Systems in remaining towns are urgently required.

Age old distributions system in many of these towns are also required to be revamped.

Most of the Rural Marketing Centers which were, a few years back, small in terms of habitations, are fast developing as small townships, such as Ranipul, Rhenok, Rongli, Pakyong, etc. These Centres are generally located in the proximity of clusters of villages as commercial and economic centers. 31 out of 55 RMCs in the State are looked after by the PHE Department. Water Supply Systems in these Centers basically consist of physical treatment and disinfection by using Bleaching Powders (chlorine). Now with the growth in population water supply systems for many of these Marketing Centers need augmentations and improvements.

Fire fighting infrastructures are being constructed and maintained by the Water Security & P.H.E. Department as per the requirement indicated by the Sikkim Fire and Emergency Services Department. The existing fire fighting system is inadequate due to rapid urbanization of towns and needs to be expanded in these towns. Presently the treated water is being supplied for fire fighting supply mains.

Efforts to provide independent supply lines with raw water is afoot. Considering the need to upgrade the fire fighting system steps are being taken to modernize the fire fighting system throughout Sikkim.

Since 1971, population growth in the State in general has been high. The rate of increase specially in Gangtok town, may be the highest in the country. Therefore, the demand of water supply in the town rose very steeply during past few years. The system also has to bear the pressure of floating population. Impact of increasing population on the water demand is illustrated below: