If you’re considering an underground or under‑driveway water tank, you’re ahead of the game. These hidden water storage solutions preserve your yard space, blend into your landscaping and keep rainwater out of sight—while still harvesting it smartly. But because these installations involve excavation, structural loads, and special plumbing, asking the right questions up front matters. Below are the top ten questions you should ask your installer before committing to a trafficable water tank – so you know you’re getting the right system, properly installed, and that it will serve you well.
1. Will the tank really handle vehicle loads? What does “trafficable” mean?
When a tank is billed as “under‑driveway” or “trafficable”, it means the unit, lid and surrounding installation are engineered to carry vehicles above. For example, the LU 5000 Trafficable Under Driveway model from The Water Tank Factory is specifically designed for driveway use.
Ask your installer:
- What load class has been certified?
- Is the lid rated for cars, 4×4s or trucks?
- Are the base and lid engineered to Australian structural standards for driveway traffic?
Hot tip: Don’t accept “should be OK”—request proof that the tank and lid are rated for the load you expect (vehicles, wheel loadings, dynamic loads).
2. How deep and disruptive will the excavation and driveway works be?
Any type of trafficable water tank, whether it be an under‑driveway or underground model require excavation to accommodate the tank footprint plus clearance and base prep.
Ask:
- How much yard or driveway will be disrupted?
- Will removal of pavers, reinforcement or concrete be required?
- Are there any overhead restraints (trees, powerlines, neighbours)?
Hot tip: If the disruption or cost seems large, compare the scope with above‑ground or under‑deck alternatives.
3. What is the maintenance access like once it’s under the driveway?
Hidden installations must still allow service access: man‑holes, lids, inspection ports, overflow access.
Ask:
- Will landscaping or paving obstruct the lid?
- Is there space provided for future pump access, overflow, cleaning?
Hot tip: Ensure the lid remains flush with driveway or path and not buried under pavers that must be removed for access.
4. Will installing it beneath a driveway affect my property value or resale appeal?
Hidden tanks can increase usable outdoor space and aesthetic appeal. But if they’re poorly installed or require major future work, they might be a hidden liability.
Ask the installer:
- Will the tank void any warranties?
- Will the driveway work comply with local building regs or council rules?
Hot tip: Having the specification, load‑rating and certification in your hand can add confidence for future buyers or certifiers.
5. What are the real cost differences compared to a standard above‑ground tank?
Trafficable water tank tends to cost more—excavation, reinforced lid, structural works, plumbing.
Ask:
- How much extra is the base, lid, backfill, driveway reinstatement?
- What are the ongoing maintenance costs?
Hot tip: Compare the premium you pay now versus the value of the space you’re retaining (garden, patio, driveway) and reflect that against future lifestyle benefit.
6. Is my block suitable in terms of soil type, slope, groundwater or other site conditions?
Site conditions affect hidden tank performance.
Ask:
- Has a geotechnical or soil report been done?
- Is the groundwater table high?
- Is the site sloping?
- Are tree roots, neighbouring structures or stormwater paths an issue?
Hot tip: If site conditions are tough (rock, high water table, steep slope) then additional fees or engineering may apply.
7. Will the installation comply with local building, plumbing and drainage regulations?
Because hidden tanks are more complex, you must ensure your installation meets all relevant standards, including overflow piping, structural design for driveway loads, insurance and plumbing legislation.
Ask:
- Will approvals be needed?
- Who handles them?
Hot tip: Having the certifier’s sign‑off, engineering drawing and documented compliance makes future maintenance and resale much easier.
8. How will the performance compare to a standard above‑ground tank?
Hidden doesn’t mean inferior.
But you need to ask:
- Will the water stay cooler and better quality?
- Is cleaning access still good?
- Do you sacrifice capacity?
The Water Tank Factory’s underground models are designed to deliver large capacity without losing performance.
Hot tip: If you expect high water usage (garden + household) ensure the hidden tank size and connections match those needs.
Hot tip: If you expect high water usage (garden + household) ensure the hidden tank size and connections match those needs.
9. What about overflow, change‑over and emergency access?
Hidden tanks still need correct overflow to stormwater or drainage, and safe access in emergency (e.g., pump failure).
Ask:
- Where is the overflow pipe?
- Is there a back‐up mains change‑over?
- How will the system be flushed or cleaned later?
Hot tip: Check the lid and riser can be removed easily for servicing, and the buried tank isn’t sealed shut.
10. Why choose The Water Tank Factory for a trafficable water tank?
Choosing an experienced supplier matters. The Water Tank Factory offers hidden/under‑driveway and underground tank options engineered for driveway use, with certified lids, specification sheets and Australian support. Their range includes trafficable underground tanks designed for driveway loading and optimised for space‑efficient installations.
Ask your installer:
- Will the tank and lid come from a supplier with trafficable certification?
- Will I receive spec sheets and warranty documentation?
- Can they support me with site preparation advice?
If the answer is no, or you get a funny feeling about certification, then give The Water Tank Factory team a call on 1300 826 532. Our friendly and knowledgeable staff are ready to get you set up for long term water tank success, no matter if you choose to go underground or above.