Water Treatment Plant


Objective of the WTP       New Picture
The main objective of the Water Treatment Plant is to treat raw water from the Melamchi River to potable standards according to the current World Health Organization Guidelines. Planning and design of the Water Treatment Plant shall take in to account for the proposed future expansion of capacity. Upstream of the Water Treatment Plant is the Melamchi Diversion Scheme and downstream of the WTP is the Bulk Distribution system.

Raw water diverted through 26.0 Km tunnel from Ribarma at Melamchi River to Sundarijal will be treated to produce drinking water of WHO Standerd. The ultimate capacity of the water treatment plant will be 510 mld. The plant is to be developed in two phases, i.e. of 170 MLD in 1st phase of project and the other 340 MLD in 2nd phase when additional 340 MLD water will be diverted from Yangri and Larke Rivers.

The water treatment plant is to be located near Mahankal, a village on the left bank of the Bagmati River about 12 km northeast of Kathmandu city at an elevation of approximately 1400 m, such that the plant will be able to distribute treated water by gravity to existing and proposed storage reservoirs in the Valley. A conventional treatment process is proposed and which includes pre-treatment, sedimentation, lime dosing, rapid sand filtration and disinfection

The second stage will be accomplished by duplicating the major facilities of the 1st  phase, preferably the performance and design will be enhanced depending upon the loading on the facilities constructed under phases 1 and 2.



The Comonent of the Melamchi Water Supply Project is funded by the Japan Bank for International Co-operation (JBIC). The designed capacity was 170 mld with provision of the future expansion. In the first phase of project. The design of phase 1 allows for the complete development of the site over the three phases, and some facilities are, therefore, sized for the ultimate capacity. Now the project is implemented in two phases. Under the 1st phase of WTP the capacity is scaled down to 85 MLD in recommendation of JICA.

The work under this Contract will include, but will not be limited to, furnishing all labor, materials, appurtenances, tools, equipment and construction technology necessary for the Melamchi Water Supply Project, Contract No. WTP/01, Construction of Water Treatment Plant at Sundarijal and which includes both civil and electrical/mechanical work to construct:

  • the connection to the pipeline laid under the Melamchi Diversion Scheme (MDS) from the end of the tunnel to near the water treatment plant;
  • Construction of the Water treatment plant includes the receiving chamber, mini-hydro power generation(200KW), distribution chamber, flocculation basins, 3 sedimentation basins, 8 filtration units, pipe gallery, 1 clear water reservoir (13.8ML), 2 sludge lagoons, Central Building Complex comprising chemical facilities, maintenance facilities and administration facilities and on-site pipework;
  • the treated water transmission main from the treatment plant to the connection with the bulk distribution system (BDS);
  • all ancillary works including roads and site works; and
  • Testing, commissioning and training of MWSDB (or other designated) personnel for the works under the Contract.

Sundarijal Water Treatment plant is designed as the SCADA system operated largest Water Treatment Plant in the country.

Progress till December 2017

On 31st December 2017, all the facilities considered to be critical to operation of Sundarijal Water Treatment Plant were complete and had been operated over extended periods.

WTP was subjected to 168 Hour Test on completion, which was completed on 11th November 2017.Test on completion was performed with raw water from Baghamati River supplied through twin 355mm OD gravity pipelines.

In January 2016, the installation of piping, valves and gates in the various structures is commenced. NEA connected the mains power supply to Sundarijal WTP on 10th August 2017. The 11kv/33kv transformer and HT panel, which enable the project 33kv/400V transformer to be connected to the 11kv network available with NEA. During December 2017 the building services installations were completed.

Up to date training for 18 people is provided for Operation and Maintenance of the treatment plant.

Total expenditure under the contract is 3,45,24,82,000.00 NPR.

Remaining works under the contract

Relocation of Shrine inside the WTP complex construction of community building are some extra works remaining which are associated with contract WTP-01. These works has not any impact on operation of Water Treatment plant. The operation of Water Treatment Plant will be started immediately after receiving water from Melamchi Diversion Tunnel.




ADB has been provided additional financing (loan 3255) to MWSDB for construction of 85 MLD water Treatment Plant as a capacity expansion of Sundarijal Water Treatment Plant from 85 MLD to 170 MLD.  NJS and associates have prepared design reports and bid documents for part -2  of WTP (WTP-02). The work has been awarded and contract signed with the contractor Tundi Construction Pvt.Ltd. and-Pratibha Industries JV. The contract agreement was made on 7th November 2016. The scheduled completion date is 23rd July 2018. The total contract price is NPR 1375155063.86 without VAT.

Eptisa Servicios de Ingenieria SL (Spain) in association with Tech Studio of Engineering (Nepal), SILT Consultants (P) Ltd. (Nepal), TEAC Consul P Ltd.(Nepal) and GeoCom Nepal Consult Pvt. Ltd (Nepal) have been awarded contract for design review and construction supervision of WTP-02, Capacity Expansion of Sundarijal WTP from 85 MLD to 170 MLD.