Welcome to our FAQ page.
Here, we answer common questions about our community services and
how we can help residents stay prepared for wet weather.
From practical tips on protecting your home to information about
our support programs and volunteer initiatives.
This section is designed to give the guidance you need.
If you don’t see your question here, ask us. We’re here to help you stay safe, informed, and rain ready.
Frequently asked questions
Q1: Isn’t this initiative alarmist?
No. The rainfall figures are recorded. The hydraulic volumes are calculable. The mechanics are standard. The geotechnical consequences of heavy rainfall are well known. The outcomes have been noted in the press. The solutions are well documented.
Q2: Haven’t retaining walls solved the problem?
Retaining walls resist soil loads. They do not remove rainfall volume. They will absorb water and experience higher loads. Not all water exits at the base or over-tops the wall. Water is also retained. When a retaining wall drain begins to run the the soil behind it is already wet and heavy. The wall is then under peak static load.
Q3: Don’t soak holes help?
On flat land, sometimes. They reduce flooding, but inject water into the ground raising the local and downstream water table.
On slopes, concentrated injection of roof water increases local soil moisture and reduces soil stability.
Q4: Isn’t this council’s responsibility?
Property stormwater control and management are shared neighbourhood realities.
Q5: Are we saying disaster is imminent?
No.
We are saying cumulative moisture increases probability of moderate failures over time.
Q6: What’s the real risk?
Repeated moderate slips affecting insurance, property values, and confidence. In extreme cases, serious harm is possible.
Q7: What about the expense?
Yes, there is expense to protect your life and property. We have developed very low cost solutions that you, your family and community helpers can install. You can also engage landscape gardeners or other contractors to use these solutions if you wish but at a higher cost. Remember, heavy rainfall events are becoming more frequent. There are good solutions.
Q6: What drainage work am I permitted to do?
Under New Zealand law and Building Performance guidelines, homeowners can legally undertake surface-level water management and minor garden drainage as DIY projects without a registered drainlayer, provided the work does not connect to the public stormwater or wastewater network.
Permitted DIY Projects (No Professional Required)
Homeowners can generally perform the following without a registered drainlayer:
• Surface Landscaping: Re-grading or contouring the ground to direct water away from buildings and towards natural dispersal areas.
• Permeable Surfaces: Replacing hard concrete with gravel, permeable pavers, or bark mulch to increase natural soakage.
• Swales and Rain Gardens: Constructing shallow, planted depressions that capture and filter runoff before it enters the soil.
• Independent Garden Drains: Installing minor field drains (like small French drains or scoria-filled trenches) to manage water in isolated garden areas, provided they discharge to your own land and not into a formal system.
• Gutter Maintenance: Clearing and maintaining existing gutters, downpipes, and roadside culverts on your property.
Work Requiring a Registered Drainlayer
By law, any work that involves restricted drainlaying must be done by a registered or certifying professional. This includes:
• New Connections: Connecting any drain (including a French drain or boundary pipe) to the public stormwater network.
• Modifying Public Assets: Any alteration to council-owned infrastructure, such as public stormwater pipes or large culverts.
• Repairs to Dwelling Drains: Any work on the pipes that carry waste or stormwater away from a house structure.
For more information, please visit the Western Bay of Plenty District Council.
MYTH VS FACT
MYTH: Retaining walls stop slips.
FACT: They hold soil. They also hold water. They do not remove water. They are under greatest stress when wet—especially when water
is entering faster that it is draining.
MYTH: The ground absorbs most rainfall.
FACT: During intense storms, runoff begins immediately, even on dry soil. Also if the soil is already wet. This creates a flooding factor.
MYTH: My property water stays on my property.
FACT: Water moves downhill across boundaries and gathers volume as it travels.
MYTH: Soak holes always help.
FACT: On slopes, concentrated roof and yard water injection increases soil instability risk.
MYTH: One storm doesn’t matter.
FACT: Unseasonal, cumulative moisture prevents hillsides from drying out in the natural summer/winter cycle. Wet soils are weaker
than dry soils.
MYTH: One storm doesn’t matter.
FACT: Repeated moderate events change insurance and property values. Perception of the district changes
