01
Site reconnaissance & planning
The team reviewed the survey area, site conditions and requirements for the proposed jetty to plan land and water-based data capture.
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Project case study · Lake Naivasha, Kenya
Integrated Bathymetric & Topographical Survey for Jetty Design
How Skymap Africa combined single-beam echo sounder (SBES) measurements, a remote-controlled survey boat and GNSS RTK ground surveying to map the lakebed and shoreline for Rubi Ranch Lake House.
Discuss Your Bathymetric SurveyLake NaivashaLakefront engineering site
SBES sonarUnderwater depth mapping
GNSS RTKShoreline and ground control
Integrated DEMLand-to-lakebed continuity
Project overview
Reliable site data for lakefront engineering
Skymap Africa was engaged by Rubi Ranch Lake House to undertake a combined topographical and hydrographic survey to support the design of a proposed jetty on Lake Naivasha, Nakuru County.
The engineering team needed a coherent understanding of both the landward shoreline and underwater terrain near the proposed jetty alignment. Surveying the lakebed alone would not provide the full context required to relate proposed structures to the shore.
Skymap therefore integrated terrestrial elevation measurements with sonar depth soundings, resolving the reference differences between land elevations and lake depths to create a continuous representation of the site.
Survey methodology
A joined-up workflow from shoreline to lakebed
Ground control, sonar measurements and coordinated processing were combined to provide engineering-ready topographic and bathymetric information.
02
GNSS RTK ground survey
A CHCNAV multi-constellation GNSS receiver, used with the MUYA CORS network, captured shoreline topography and relevant terrain features.
03
Single-beam sonar survey
A calibrated Chirp single-beam echo sounder on a remote-controlled survey boat recorded depth measurements along planned survey lines, synchronized with GNSS positions.
Data processing & integration
Connecting terrestrial elevations to underwater depths
After field acquisition, the ground survey points and sonar depth records were cleaned, checked and compiled into a unified geospatial dataset. Time, position and depth information from the boat was synchronised to support spatially consistent bathymetric mapping.
The processing team reconciled the reference levels for the land and water datasets to establish a continuous elevation model across the shoreline transition. This integrated digital elevation model (DEM) represents both the lakefront terrain and the lakebed in a common engineering context.
Combining the two datasets helps designers understand the relationship between the proposed jetty, the shore profile and the underwater ground conditions.
Project outputs
Engineering information delivered for design
The final survey products translated the field measurements into spatial information that can be interpreted and used by design teams.
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Integrated topographic & bathymetric map
A combined map of the land and lakebed, presenting the surveyed area in one consistent layout.
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Longitudinal profile
A profile extracted from the integrated model to support assessment of the proposed jetty alignment.
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CAD-compatible drawings
Digital mapping and PDF plots prepared for use in common CAD-based engineering workflows.
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Integrated elevation model
A continuous representation of shoreline topography and underwater terrain for engineering interpretation.
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GNSS-referenced ground data
Terrestrial survey points tied to the project’s coordinate reference approach for a reliable landward baseline.
✓
Safer water-based acquisition
The remote-controlled boat allowed sonar data collection without a surveyor needing to operate the boat directly.
Project workflow
From field measurements to design-ready data
01 / PLAN
Understand the site
Review the jetty design needs, access and survey limits.
02 / SURVEY
Capture land & water
Measure shoreline terrain with GNSS RTK and lake depths with sonar.
03 / INTEGRATE
Unify reference levels
Process the terrestrial and hydrographic datasets into one elevation model.
04 / DELIVER
Prepare design outputs
Produce maps, profiles and digital files to support engineering interpretation.
Bathymetric survey services
Mapping below the waterline across East Africa
Skymap Africa combines hydrographic survey methods and land surveying to provide site data for lakefront developments, dams, reservoirs and other water-related infrastructure.
- Bathymetric surveys using single-beam sonar
- Remote-controlled and unmanned survey boat workflows where suitable
- GNSS RTK shoreline and ground surveys
- Integrated land-and-water elevation models
- Longitudinal profiles and CAD-ready survey mapping
- Repeat bathymetric surveys for dam volume and sedimentation monitoring
Frequently asked questions
Bathymetric survey FAQs
What is a bathymetric survey?
A bathymetric survey measures underwater depths and represents the shape of a lakebed, riverbed, reservoir bed or other submerged terrain.
Why combine bathymetry with a topographical survey?
Combining both methods links the underwater terrain to the shoreline and surrounding ground, giving engineering teams a more complete site model for design.
What equipment was used at Rubi Ranch Lake House?
The report describes a calibrated Chirp single-beam echo sounder, a remote-controlled survey boat, and a CHCNAV multi-constellation GNSS receiver used with the MUYA CORS network.
What can the outputs be used for?
The integrated map, elevation model and longitudinal profile provide site information to support jetty engineering design. Final design decisions remain with the appointed engineering team.
Planning a jetty, lakefront or reservoir project?
Speak to Skymap Africa about bathymetric mapping, shoreline surveys and integrated engineering data.