i. Construction
of Tunnel and Headwork The
major work under this scheme is the
construction of Diversion tunnel approximately
26.3 km long excavated by drill and
blast method in order to divert 170
MLD of raw water from Melamchi River
to Sundarijal outlet where the raw
water is treated before sending it
to Bulk Distribution System (BDS).
The contract for construction of headworks and tunnel was awarded on 19 February 2009 with intended completion date of 2 September 2013. Actual physical works started in April 2010. But due to the unsatisfactory performance of the Contractor it was terminated on 25 September 2012.
Other additional works comprises
the construction of:
 |
Headwork diversion
tunnel and temporary cofferdams
on the Melamchi and Ribarma Rivers |
|
Headworks intake structures,
including earthworks, cuts, civil
works and hydraulic steelworks
|
|
Adits from portals at ground
level to the Diversion tunnel
at Ambathan, Gyalthum and Sindhu
Excavated at 18.4 m2 cross sectional
area |
|
Gate valve arrangements at portals
and spillway/bypass flushing system
to Bagmati River other control
works at downstream and portals
and Sundarijal |
|
Tunnel Flushing system at Ambathan
adit |
|
River training and intake at
Ribarma with de-sanding basin |
|
Pipeline (of 1.6 m dia.) from
tunnel portal to WTP, length approximately
235m |
ii. Construction
Maintenance and Management of Access
Roads
Access Roads refer to the roads used
to visit different Adit points (project
sites) including main intake. This
includes the construction of about
43 km of access roads and upgrading
of about 29 km of existing roads making
easier / accessible to visit project
sites (Adit points) round the year.
More specifically these access roads
are categorized as:
Adit Access Road (AAR) – AAR refers
the roads to reach to different Adit
points of the project sites which
include – Sindhu Adit (Bahunepati
– Sindhu Adit ,15.4 km), Gyalthum
Adit (xxxxx to Gyalthum Adit, 4.2
km) and Ambathan Adit (Timbu – Main
Intake at Ambathan Adit, xx km)
Main Access Road (MAR)– MAR refers
the road from Melamchi Pul Bazar to
Timbu which length18 km long including
10 bridges.
Upgrading Access Road (UAR)- Upgrading
of Jorpati-Sundarijal road (6.0 km),
Jorpati Gokarna-Narayantar and Lamidanda
- Melamchi Pul Bazar – Timbu (feeder
road), 22.2 km.
In addition to the above roads,
this package also includes:
|
Maintenance of
Lamidanda-Timbu feeder road the
Headworks access road and the
four Adit Access Roads-Sundarijal,
Sindhu, Gyalthum and Ambathan; |
|
Construction of approximately
235 m length of road as an extension
of the Sundarijal AAR up to Sundarijal
Portal; and |
|
Construction of approximately
45 m length of road to access
the Sindhu Adit portal. |
iii. Construction,
Operation and Management of Camp site
Offices
This is also an crucial part of
the works to be completed by the Contractor
under the Melamchi Diversion Scheme
(MDS). This refers the construction,
operation and management of Camp site
office at Malamchi Pool Bazar (main
Camp) and Other Camps at Ambathan
Adit, Gyalthum Adit, Sindhu Adit and
Sundarijal Adit.
This also includes the operation
and maintenance of camp site facilities
to (Employer/Engineer) such as power
supply, telecommunication/internet,
water supplies, sanitation/sewerage
disposal, garbage; camp roads; buildings;
structures; security; accident &
emergency; safety; fire equipment;
welfare; laundry and recreation facilities
as agreed in the Contract.
This package also covers procurement
of various equipments, vehicles etc.
needed for project implementation
and bear its operational cost including
fuel, periodic maintenance to both
Employer and Project Engineer (DSC).
The responsibility of operation and
management of storage of explosives,
construction materials, testing system
etc. also goes to the Contractor.
Not only at the Adit camps, the contractor
should takeover and operate all existing
services of Main Camp Site office
located at Melamchi Pool Bazar. |
