Consultancy Topographical Survey for Urban Rainwater Drainage Design Tender, Somalia - 50881632

Procurement Summary

Country : Somalia

Summary : Consultancy Topographical Survey for Urban Rainwater Drainage Design

Deadline : 11 Mar 2021

Other Information

Notice Type : Tender

TOT Ref.No.: 50881632

Document Ref. No. :

Competition : ICB

Financier : Other Funding Agencies

Purchaser Ownership : -

Tender Value : Refer Document

Purchaser's Detail

Purchaser : CONCERN WORLDWIDE
BANADIR REGION
Somalia
Email :procurement.mogadishu@concern.net / haron.emukule@concern.net / paz.lopez@concern.net

Tender Details

Tenders are invited for Consultancy Topographical Survey for Urban Rainwater Drainage Design in Yaqshid and Karaan Districts (Banadir Region), Somalia.

TERMS OF REFERENCE FOR

CONSULTANCY TOPOGRAPHICAL SURVEY FOR URBAN RAINWATER DRAINAGE DESIGN IN YAQSHID AND KARAAN DISTRICTS (BANADIR REGION), SOMALIA

Job Description

TERMS OF REFERENCE FOR CONSULTANCY TOPOGRAPHICAL SURVEY FOR URBAN RAINWATER DRAINAGE DESIGN IN YAQSHID AND KARAAN DISTRICTS (BANADIR REGION), SOMALIA

1. BACKGROUND

Concern Worldwide is a non-governmental, international, humanitarian organization dedicated to the reduction of suffering and working towards the ultimate elimination of extreme poverty in the world-s poorest countries. Concern engages in long-term development work, responds to emergency situations, and seeks to address the root causes of poverty through development, education and advocacy work.

2. CONSULTANCY SERVICE

Concern Worldwide is a member of the Building Resilient Communities in Somaliland (BRCiS) consortium and is currently implementing theprogramme Somaliland Humanitarian and Resilience Programme (SHARP) funded by the UK-Government Foreign and Commonwealth Development Office (FCDO) for the period 2018-2022. The programme goal is to enhance the resilience of vulnerable and marginalized communities to recurrent shocks and stresses and engage in sustainable nutritionally sensitive livelihood strategies.

In Banadir region, Concern Worldwide and the implementing partner, Youthlink, engaged with five communities in 2019 to lead a vulnerability and risk analysis and a participatory process to prepare Resilience Community Action Plans in coordination with district authorities. The Community Action Plans consider in Sahan community (Yaqshiid district) and Bulo Eyle community (Karan district) consider mitigating the recurrent risk of urban flash-flood through improvements in the storm water drainage infrastructure. The purpose of this consultancy is to conduct a topographical survey and related assessments in the preselected urban communities to establish the topographical conditions that will inform construction of drainage channels aimed at draining the accumulated storm water during rainy seasons. This will improve the sanitary conditions of communities living in the area, reducing the transmission of water related diseases and the negative impacts of recurrent flooding on urban poor livelihoods.

3. OBJECTIVES
To carry out the topographical (topo) survey using latest topographic
survey equipment (Total Station, Auto Level, Digital level, differential
GPS (DGPS), and Global Navigation Satellite System (GNSS)),
preparation of layout map and digital terrain model for construction of
drainage in Sahan community in Yaqshid district and Bulo Eyle
community in Karan district. The terrain between these locations is
gentle sloping and highly populated with limited access along the
existing route. The proposed drainage will be along the existing road, or
be in close proximity, to the existing road determined by the topography.
The survey will be carried out in stages, with the lower level alignment
carried out initially and higher elevations carried out at a later stage. The
subsequent stage of topographic survey will be completed within 20
days.
Topo mapping shall be carried out for a minimum width of 20m from
centerline on each side of the road (total width 40m) along the proposed
stretch estimated distance of 2km, for each village. The survey shall
cover any possible seasonal stream section adjacent/ parallel to the
road.
Also, the survey extent shall be increased based on consultant
requirement.
If additional survey will require during the detailed design stage due to
changes in alignment or any other purpose, the consultant shall perform
the survey based on Concern Engineer requirement.
Coordinates of proposed alignment shall be provided to the survey team
for all required areas.
The contactor shall fulfil any changes required in Topo Survey during the
design stage.
The sections shall be taken every 10m spacing along the proposed
alignment. The UTM coordinates system shall be followed for the survey
work.
Due to the nature of the terrain and climatic conditions along the
proposed alignment the site works will be carried out within
Carry out Environmental Impact Assessment (EIA) for the proposed
boreholes to ensure that proper planning is done and that likely potential
negative impact that might arise from developing the project are
identified and that appropriate mitigation and monitoring measures are
included in the project design.
4. LOCATION
The geographical scope of the project covers two distinct urban
communities:
Name of the site N
o E
Sahan community in Heegan subdivision on Yaqshid district. 2° 3-17.79″N 45°21-8.06″E
Bulo Eyle community in Nageyle
sub-division of Karan district. 2° 3-32.09″N 45°22-1.77″E
Within each community, YouthLink and Community Resilience
Committees (CRC) have identified the high flood-prone areas and
vulnerable households affected, estimated to 200 household in Bulo
Eyle and 150 households in Sahan.
5. METHODOLOGY
The Consultant shall provide details of resource (professional surveyors
and labour), specialist survey sub-Consultants (if required) and plant
(calibrated and sufficient to provide the specified accuracy along with the
bid.
The Consultant will submit a program of the site survey teams, which are
anticipated to be a minimum of 4No, such that the works can be
completed within the limited time period available for site access. The
program, including plant and survey teams will be submitted with the bid
to provide assurance that the Consultant is capable of completing these
works within the limited access period.
The topographical survey shall consist of the following:
o Fixing of Primary survey control with static method use GNSS
adjustment and GNSS salutation software;
o Fixing of Secondary survey control with RTK fixed and AutoCAD
Civil 3D 2018 & related Software;
o Vertical Controls by Auto level/ Digital level machine;
o Details topographic survey, and
o Data analyse and preliminary survey drawing provide A3 Size
(including plan, profile and cross sections).
Level Traversing shall be conducted using Auto level/ Digital level and
having accuracy of +/- 5mm in 1 km double run. Benchmark pillars shall
be connected to nearest bench mark. Benchmark level also to be
transferred on major permanent structures at least once in every 250m
with sequential numbering and as per the instructions of the Engineer in
charge of the site.
The Total station traverse shall be closed with the nearest pillar.
Traversing shall be carried out using (having an accuracy of two sec.) to
fix the co-ordinates on the benchmark pillars. Two rounds of angle
measurements to be taken on both left and right face in both clockwise
and anticlockwise direction. The angle spread between observed round
shall not be more than 5 sec. Traverse shall be closed within an
accuracy of 1 in 20000.
Topographic survey is to be carried out using latest topographic survey
equipment (Total Station, Auto Level, Digital level, differential GPS
(DGPS) and GNSS), the horizontal and vertical accuracy shall be +/-
5mm. The equipment shall be checked periodically for horizontal and
vertical collimation. Vertical control must be done by Auto/ Digital level
machine.
For the Primary survey control point, Dual reference pillars shall be
established once in every 1 km using GNSS Static method having valid
calibration certificate. Reference pillars shall be in the form of concrete
blocks of size 40 X 40 X 120cm with proper foundation as per the
instructions of the Engineer in charge of the site and shall be embedded
to a depth of minimum 40cm in to the ground. The transfer time shall be
such that the accuracy achieved shall be better than 1 in 20000.
Regarding the Benchmark Pillars Specifications, Benchmark (BM) pillars
shall be established at 250m intervals in the form of precast concrete
blocks of size 30 X 30 X 60cm and shall be embedded to a depth of
30cm in to the ground. The BM pillars shall be painted in yellow and
details such as BM number and reduced level shall be clearly marked on
it with red paint. All BM pillars shall be numbered sequentially as per the
instruction of the Engineer in charge of the site. Wherever the new
benchmark pillars are laid, the level traverse shall be closed.
5.2 Environmental Impact Assessment
Conduct an environmental impact assessment for the project which
includes;
o Nature of the project, location of project area
o Activities that shall be undertaken during the construction of the
drainage channel
o Project design, materials to be used and by products, and
disposal methods.
o Identified environmental impacts of the project (both positive and
negative) during the i) survey phase and ii) the drainage
construction phase.
The assessment should consider impacts on:
-Water resources
-Soil/land
-Vegetation
-Land use
o Economical and socio-cultural impacts associated to the potential
environmental impacts identified.
o Any other information the authority may require.
5.3 Production of designs Drawings and Bill of Quantities
Based on the data collected, produce detailed drawings, BOQ and
technical specifications of the works to be undertaken.
6. DURATION OF WORKS
The duration of the consultancy will be decided by the consultant in
agreement with the WASH and construction Coordinator but should not
exceed 20 days from the date of signing agreement. A proposed work
and travel plan will be developed during the consultation meeting above.
The consultant will prepare a tentative work plan for the study and
include this in their offer. The work plan should set out the timelines of
the following activities;
o Acquisition and review of secondary data in the office;
o Assess

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