ANNEX II - SCOPE OF SERVICES
The selected contractor shall be required to carry out engineering topographical survey of
pipelines, site surveys and other works described herein and Annex IIA to the following
specification, and will involve topographic surveying and leveling (longitudinal, cross sections,
site survey at bridges, stream and other crossings and layout plan) along the pipe traces and
selected other locations and preparation of drawings on electronic files and hard copies.
1.1 GENERAL
 The topographical survey shall be carried out using Total Station technology and profiles
with Dumpy / Engineering Level.
 The contractor shall establish Temporary Bench Marks (TBM) from established Bench
Marks (Government or otherwise) in all significant locations such as intakes, treatment
plants, reservoir locations or any other important locations and selected places in
pipelines. The locations for TBM for pipelines shall be agreed with UNOPS in such a
manner that no two TBM are more than 2km apart, measured along pipe routes or roads.
 All TBMs shall be established with concrete poles, securely held in ground to be used
during construction, and numbered in sequence. The contractor shall produce a drawing
showing designated number of TBMs, its co-ordination and elevation.
1.2 PIPELINE PROFILES
 A closed traverse survey showing and identifying all important features such as bridges,
culverts, underground electric lines, electric posts, telephone posts, existing utilities,
manholes and any other shall be carried out and shown on drawings for each of the
pipeline route. The existing utilities (if any) such as telecommunication manholes shall be
clearly identified in the drawings with an appropriate abbreviation for utility agency.
 When pipelines traverse along roads, full road width shall be shown on the drawings
clearly demarcating paved edge (if any) and all utilities described above. The stretches of
roads belonging to different authorities shall also be indicated with chainages.
 For surveying pipelines and production of drawings, the contractor shall use the same
node numbers that UNOPS incorporates in the map in Annex IV or to be provided during
surveys. The survey shall always commence from lower node to a higher node.
 The levels shall be taken at least every 20m intervals for longitudinal section and shall
include the junctions of by-roads and points of change of gradients such as soffit and
invert levels of culverts, soffit and invert levels of bridges and water levels of relevant
rivers and streams.
 The level lines shall always be closed with a fly-back.
 The levels shall be determined with reference to bench marks established by the accepted
country surveys (National Grid).
 Cross sections along the pipeline routes up to 10m on either side of the centerline of the
road shall be taken at special locations where culverts, bridges, water courses, etc. are
encountered. For pipelines traversing along roads, levels shall be taken at the edge road to
facilitate pipe laying on shoulder. The contractor shall at all times verify the side of the
road for proposed pipeline or follow instructions from UNOPS prior to commencement
of surveys for each route.

All important features along the pipeline route shall be identified and plotted while
performing the survey work with particular emphasis on the following items.
–
Existing utilities, manholes (shall be marked with utility), culvert and bridge
details (width, length, invert level, type, size of opening, depth between road
surface and top of structure, etc.)
–
Important buildings (schools, mosques, government buildings, etc.)
–
Rivers and streams
–
Details regarding existing water supply pipe lines or other (diameter of pipe, type,
side of the road along which it is laid, etc.)
–
Details relating to other underground service installations (sewers, electrical
cables, telephone cables, storm water drains, etc.)
–
Location of electricity and telephone poles.
–
Details of any property which is likely to be damaged or affected by pipe laying.

The starting point and end points of all pipelines shall be carefully selected so as not to
miss any pipe stretches in the middle. (e.g. when pipelines originate from intake to
treatment plant, the start and end of the pipeline shall be taken as the boundary of intake
and treatment plant)
All existing pipeline ground levels shall be plotted against longitudinal distance
(measured along pipe route) versus elevation to a scale shown in 4.6 using AutoCAD or
similar engineering drafting software.

1.3 CROSS -SECTION SURVEY
Cross sections shall be taken at every 100m intervals along the transmission pipeline routes
up to 10m on either side of the centerline of the road or up to the road boundary where it
extends beyond 10m from the road centerline. Additional cross sections shall be taken at
special locations where culverts, bridges, water courses, etc. are encountered. The levels shall
be taken at the centre of road, edges of surfaced area, shoulder edges, boundary fences, etc.
as required.
1.4 SURVEY OF E XISTING B RIDGES
 The bridges encountered along the pipe route shall be surveyed separately in detail. A
“bridge” for this purpose is defined as a structure over a water course with and opening of
more than 4m or as indicated by UNOPS.
 The length of the bridge, deck width, type of the bridge and other relevant details shall be
provided.
 A detailed survey at the site, including spot levels on the embankment and bed of the
watercourse shall be included.
 Detailed drawing of bridge surveys covering at least 20m either side from the centerline
of the road shall be prepared to an appropriate scale incorporating the spot levels and
contours.
1.5 SURVEY OF NEW AND EXISTING STRUCTURE AND SITES (I NTAKE, RESERVOIR SITES,
PUMP HOUSE ETC.)
 When a pipeline originates from a Premise such as Intake, Treatment Plant, Pump House,
Reservoir or any other, a full site contour survey showing all structures, important

features, manholes, valve chambers, flow meter chambers, underground utilities etc shall
be carried out and shown on respective drawings for the site with contours at 1m
intervals.
There are two (2) defined lands namely proposed pump house location in Golo and
existing treatment plant in El Fasher. However, depending on the nature of altitude of the
pipeline, a survey of an additional land (100mx75m) adjacent to the pipe trace may be
required. The extent of land for proposed pump house and new location (if any) is
roughly 100mx75m and that for treatment plant is roughly 100mX100m.

The site survey for Golo shall show the location and elevation of existing pump house at
Golo and all important features such as levels of pipe inlets, outlets and top and bottom
levels of manholes and chambers, their inlet and outlet levels and sizes. The contractor
shall further record crest level of Golo main reservoir bund, spill(s), outlet levels to two
Hafiers, their sizes and outlet levels and sizes from Hafiers to existing pump station.

The site survey for treatment plant in El Fasher shall show all important features on the
sire such as structure, manholes, chambers, exposed, underground pipelines and other.
The contractor is also required to record top and bottom levels of all manholes and
chambers, their inlet and outlet levels including sizes and any other. Further, site survey
for existing reservoir locations shall show, in addition to contour map of respective land,
the ground level of the tank, level of tank bottom, level of tank top, level of inlet, outlet,
overflow and washout etc. In the event tank is in different elevations, above data should
be recorded for each component of the tank.
1.6 OTHER REQUIREMENTS
The contractor shall abide by following instructions/ guidelines during the course of survey.
 Contractor shall promptly notify UNOPS of any ongoing or proposed development
activities such as new underground telephone service, electricity service, property
development etc.
 Establish local names of the roads correctly including all byroads and indicate in the
drawings.
 Identify any stretch of pipe route requiring specials attention (e.g. marshy lands, rock out
crops, etc.) and include on the drawings.
 Identify any record any land (other than road reserves) involved along the surveyed
pipeline routes.
 Key plan shall be prepared to a scale of 1:10,000
 Longitudinal sections shall be drawn to the scales of 1:1000 (horizontal) and 1:100
(vertical). L.S and traverse survey shall be drawn on the same sheet.
 Cross sections shall be drawn to a scale of 1:100 (horizontal) and 1:20 (vertical) on
separate sheets.
 Locations and levels of Bench Marks shall be indicated on the traverse. A separate Table
shall be provided indicating all TBMs along the route and their respective locations.
 PBM and TBM used on the survey work shall be marked with an appropriate paint and
photographs submitted for the bench marks both in soft and hard copy.
The bidders are strongly advised to visit the site, obtain local information and get
acclimatized to the project area prior to submission of their bids.
Bidders are advised that UNOPS, prior to course of surveys, may modify the pipeline trace
shown on the map or pump house location if such changes are deemed necessary without
incurring any liability for such changes. Since the work is paid for by measure and pay basis,
in the event of such changes, UNOPS does not entertain any claim of what so ever nature
arising as a result of work quantity being modified due to UNOPS requirements.