By the end of this chapter, you will be able to:
These skills are essential because they help you create safe, efficient, and client-focused water storage solutions in real civil engineering projects.
Water tanks are essential infrastructure components in civil engineering projects, especially in Kenya where water storage and distribution are critical due to variable rainfall and urban demand. Quantity Surveyors must accurately interpret and prepare water tank drawings to ensure precise estimation, procurement, and project management. This chapter focuses on the types of water tanks commonly used and the determination of pipe layouts necessary for efficient water delivery and structural integration.
Water tanks vary by location, purpose, and structural design, impacting their drawings and costing. Quantity Surveyors in Kenya encounter mainly elevated and underground water tanks in construction projects ranging from residential estates to institutional facilities. Correct identification and detailing of these types influence material take-offs and labor cost estimations.
Elevated water tanks are raised above ground level to provide water pressure by gravity, commonly used in urban housing estates and hotels.
Definition and purpose
Elevated tanks store water at height, enabling gravity-fed water supply without continuous pumping. This reduces energy costs and ensures steady pressure in distribution networks.
Structural components
Key parts include the tank body (usually circular or rectangular), supporting columns or pedestal, access ladders, and overflow pipes. Each component must be dimensioned correctly in technical drawings.
Materials used
Common materials are reinforced concrete, steel, or a combination. Concrete tanks offer durability and resistance to corrosion, while steel tanks allow faster construction and easier relocation.
Design considerations
Load calculations for water weight, wind forces, and seismic activity must be integrated into drawings. Accurate representation of these factors ensures structural safety and compliance with Kenyan building codes.
Typical drawing standards
Drawings follow BS 8887 and ISO 128 standards for line types and symbols. Scales commonly used are 1:50 for general layout and 1:20 for detailed sections.
Underground tanks store water below the earth surface, commonly used to save space and protect water from contamination and evaporation.
Definition and applications
These tanks are buried and connected to water supply and distribution systems. They are widely used in schools, hospitals, and county government offices where land conservation is critical.
Construction materials and methods
Materials include reinforced concrete and polyethylene. Concrete tanks are cast-in-situ or precast, requiring waterproofing and corrosion protection detailed in drawings.
Structural design elements
Design must consider soil pressure, hydrostatic forces, and access for maintenance. Drawings need to show reinforcement details, access openings, and ventilation pipes.
Ventilation and overflow systems
Proper ventilation prevents anaerobic conditions and maintains water quality. Overflow pipes direct excess water safely, all of which must be clearly indicated on drawings.
Drawing conventions and scaling
Use of sectional views and detailed reinforcement drawings is essential. BS 8000 standards guide the representation of underground structures and associated fittings.
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Create a free accountThis chapter focused on preparing water tank drawings by first exploring the different types of water tanks, specifically elevated and underground tanks, highlighting their structural distinctions and typical uses. The process of determining the pipe layout was then examined, emphasizing the importance of efficient plumbing design for optimal water flow and system functionality. Soil analysis was covered to ensure the foundation and location of the water tank are suitable for long-term stability and safety. Finally, the chapter detailed the design and drawing of water tanks, including the necessary technical specifications and standards to produce accurate and practical construction documents. Together, these topics provide a comprehensive guide for creating precise and reliable water tank drawings in civil engineering projects.
Type: Individual
| Tools & Equipment | Materials |
|---|---|
| Drawing paper A3 size | Reference charts on water tank types |
| Pencils HB and 2B | |
| Eraser | |
| Ruler 300 mm | |
| Set square 45° and 60° | |
| Compass | |
| Colour pencils |
| S/N | Item | Quantity |
|---|---|---|
| 1 | Drawing paper A3 size | 1 Pc per Candidate |
| 2 | Pencils HB and 2B | 1 set per Candidate |
| 3 | Eraser | 1 Pc per Candidate |
| 4 | Ruler 300 mm | 1 Pc per Candidate |
| 5 | Set square 45° and 60° | 1 set per Candidate |
| 6 | Compass | 1 Pc per Candidate |
| 7 | Colour pencils | 1 set per Candidate |
| 8 | Reference charts on water tank types | 1 set per Candidate |
| Items to be Evaluated | Marks Available | Marks Obtained | Comments |
|---|---|---|---|
| TASK 1: Identification and Sketching of Water Tanks | |||
| Used appropriate PPE: helmet, safety boots, reflective jacket (Award 1 mark each for any correct PPEs) | 3 | ||
| Assembled all required drawing tools and materials before starting (Award 2 marks for assembling all required tools and charts) | 2 | ||
| Identified correctly three types of water tanks (e.g. overhead, underground, ground level) (Award 1 mark for each correct identification) | 3 | ||
| Classified each tank type based on key characteristics (Award 1 mark for each correct classification) | 3 | ||
| Sketched each water tank to approximate scale with correct proportions (Award up to 4 marks for neat, proportionate sketches) | 4 | ||
| Used correct orthographic views in the sketches (elevation and plan) (Award 1.5 marks each for elevation and plan views) | 3 | ||
| Applied appropriate annotations and labels on each sketch (Award 2 marks for clear and accurate labels) | 2 | ||
| Maintained neatness and clarity throughout the drawing process (Award 2 marks for overall neatness and presentation) | 2 | ||
| Sub-Total | 22 | ||
| PRODUCT CHECKLIST | |||
| Three water tank types correctly identified and classified (Award 5 marks for all three correctly identified and classified) | 5 | ||
| Sketches show accurate dimensions approx. 2000 mm diameter and 1500 mm height (Award 5 marks for correct dimensions within ±50 mm tolerance) | 5 | ||
| Sketches include correct orthographic views (elevation and plan) (Award 4 marks for complete and correct views) | 4 | ||
| Annotations and labels are clear and correctly placed (Award 3 marks for accurate and legible annotations) | 3 | ||
| Overall presentation is neat, organized and professional (Award 3 marks for neatness and presentation) | 3 | ||
| Sub-Total | 20 | ||
| GRAND TOTAL | 42 | ||
Type: Individual
| Tools & Equipment | Materials |
|---|---|
| Measuring Tape | |
| Drawing Board | |
| T-Square | |
| Set Squares | |
| Mechanical Pencil | |
| Eraser | |
| Scale Ruler | |
| Compass | |
| Protractor | |
| Tracing Paper | |
| Drafting Pins | |
| Colored Pencils |
| S/N | Item | Quantity |
|---|---|---|
| 1 | Measuring Tape (5m) | 1 Pc per Candidate |
| 2 | Drawing Board | 1 Pc per Candidate |
| 3 | T-Square | 1 Pc per Candidate |
| 4 | Set Squares (45° and 60°) | 1 Set per Candidate |
| 5 | Mechanical Pencil | 1 Pc per Candidate |
| 6 | Eraser | 1 Pc per Candidate |
| 7 | Scale Ruler (Metric) | 1 Pc per Candidate |
| 8 | Compass | 1 Pc per Candidate |
| 9 | Protractor | 1 Pc per Candidate |
| 10 | Tracing Paper | 5 Sheets per Candidate |
| 11 | Drafting Pins | 10 Pcs per Candidate |
| 12 | Colored Pencils (Red, Blue, Black) | 1 Set per Candidate |
| Items to be Evaluated | Marks Available | Marks Obtained | Comments |
|---|---|---|---|
| TASK 1: PREPARATION AND DRAWING EXECUTION | |||
| Identified and used appropriate PPE (helmet, safety boots, reflective jacket) (Award 1 mark each for any correct PPEs) | 3 | ||
| Assembled all necessary drawing tools and materials before starting (Award 2 marks for complete assembly of tools and materials) | 2 | ||
| Correctly set up drawing board and secured tracing paper with drafting pins (Award 2 marks for proper setup and securing tracing paper) | 2 | ||
| Accurately drew the circular plan of the water tank using compass and scale (3000mm diameter to scale) (Award 5 marks for accurate scaled drawing of the tank plan) | 5 | ||
| Drew elevation view to correct height scale (4500mm) including supporting column details (Award 5 marks for correct scaled elevation with structural components) | 5 | ||
| Drew sectional view showing internal tank structure and water level (Award 5 marks for clear, accurate sectional drawing) | 5 | ||
| Added all relevant dimensions clearly and accurately on all views (Award 1 mark for each view with correct dimensions, total 4 marks) | 4 | ||
| Annotated drawing with structural notes (e.g. '4Y16 main bars', 'R8 links @ 150 c/c', 'inlet/outlet ports') (Award 1 mark each for any three correct annotations) | 3 | ||
| Used appropriate line types and weights to distinguish different elements (Award 2 marks for correct use of line types and weights) | 2 | ||
| Maintained neatness and clarity throughout the drawing process (Award 2 marks for overall neatness and presentation) | 2 | ||
| Sub-Total | 33 | ||
| PRODUCT CHECKLIST | |||
| Plan view diameter dimension is 3000mm ± 50mm tolerance (Award 4 marks for correct diameter within tolerance) | 4 | ||
| Elevation height dimension is 4500mm ± 50mm tolerance (Award 4 marks for correct height within tolerance) | 4 | ||
| Sectional view correctly shows internal components and water level (Award 4 marks for completeness and accuracy of sectional view) | 4 | ||
| Drawing is well squared and aligned; dimensions are parallel and clear (Award 3 marks for proper alignment and dimensioning clarity) | 3 | ||
| Annotations are accurate and in correct locations (Award 3 marks for correct technical annotations) | 3 | ||
| Drawing is free from errors, smudges and maintains professional standard (Award 3 marks for overall quality and professionalism) | 3 | ||
| Sub-Total | 21 | ||
| GRAND TOTAL | 54 | ||
At the start of this chapter we promised you would be able to:
Tick each one you can genuinely do.
So, are you there yet?
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