When you discover leakage of water tank walls, the bottom, or around fittings, the instinct is to patch it and move on. But a patch rarely solves the underlying problem. Water tanks, whether concrete, steel, or redwood, develop leaks for structural reasons that worsen over time. The result is lost water, increased operating costs, and potential contamination of the supply you depend on.
At Carson Liners, we have spent more than 45 years helping municipalities, water agencies, farms, and rural water associations solve this exact problem. The solution that lasts is not a patch, a coating, or a full tank replacement. It is a custom-fabricated drop-in liner, precision-built to your tank’s exact dimensions.
Below we break down why tanks leak, what your real options are, and why a custom liner is often the smartest long-term move.
Why Water Tanks Leak and Why It Gets Worse
A leaky tank is never just a surface issue. The cause depends on what your tank is made of, how old it is, and what conditions it faces. Here is what happens with each major tank type.
Concrete Water Tanks
Concrete is the most common material for large water storage tanks, and concrete cracking is the most common cause of leakage of water tank structures nationwide. The culprits include:
- Thermal expansion and contraction: seasonal temperature swings cause micro-cracks that widen year after year
- Ground settling and seismic movement: especially in California and the Western US, soil movement stresses tank walls and floors
- Aging and carbonation: over decades, concrete loses alkalinity and the reinforcing steel inside begins to corrode, accelerating cracking from within
If you are searching for a cement water tank leakage solution or concrete water tank leakage solution, the core problem is the same: once concrete cracks, water finds its way through. If you’re looking for a concrete water tank leakage solution, patching individual cracks is a temporary fix at best. New cracks keep forming as the underlying stress continues.
Steel Tanks (Bolted and Welded)
Bolted steel and welded steel tanks develop leaks primarily through corrosion. Coastal environments, humid climates, and tanks storing chemically treated water are especially vulnerable. Corrosion attacks from both inside and outside the tank walls, and by the time you see a water tank leaking from bottom joints or bolt holes, the damage is often extensive beneath the surface.
Redwood and Wooden Tanks
Redwood tanks are prized for their natural beauty and longevity, but they are not immune to time. Wood rot, warping from wet-dry cycles, and stave separation create gaps that allow steady water loss. Many owners of heritage redwood tanks assume replacement is their only option. A custom liner lets you keep the original structure and stop the leak for good.
Your Options When a Tank Starts Leaking
When you have a leaky tank, you have four realistic paths. Not all of them make sense for every situation.
| Option | Typical Cost | Downtime | Longevity | Best For |
|---|---|---|---|---|
| Patching or sealing | Low | Hours | 1-3 years | Minor, isolated cracks |
| Interior coatings | Moderate | Days to weeks (curing time) | 5-10 years | Surface-level deterioration |
| Full tank replacement | Very high | Weeks to months | 20-40 years | Structurally failed tanks |
| Custom drop-in liner | Moderate | Days | 20+ years | Most leaking tanks |
Patching and sealing work for small, isolated issues, but if your tank has multiple leaks, hairline cracking across a wide area, or leakage from structural joints, a patch will not hold. Coatings require extensive surface preparation, long cure times, and the tank must be completely dry. Replacement means demolition, permitting, new construction, and weeks or months of downtime.
A custom drop-in liner addresses the root problem differently. Instead of trying to seal a deteriorating structure from the outside, a liner creates a completely new, watertight barrier inside the existing tank shell. The tank structure stays in place. The liner does the holding.
Water Tank Leakage? Custom Liner Repair
Carson’s process for stopping tank leakage is straightforward and proven across hundreds of installations:
- Assessment: We evaluate your tank type, dimensions, the nature and extent of the leaks, and what the tank stores. For potable water, this determines which NSF 61 certified materials are required.
- Custom fabrication: Every liner is precision-fabricated at our facility to your tank’s exact measurements. For rectangular tanks and irregular shapes, we use box-welding techniques that produce clean corners with no folds or wrinkles. For round tanks, depending on the size of the liner, we either wedge weld the circular seam in house or in the field. There are no solvents or adhesives, only factory-welded seams tested under rigorous quality inspection.
- Material selection: Depending on your application:
- Reinforced Polypropylene (RPP): our most specified material for potable water tanks, NSF/ANSI Standard 61 approved for drinking water contact
- Reinforced Polyethylene (RPE): the most durable liner material available, with exceptional tensile strength
- Chlorosulfonated Polyethylene (CSPE): outstanding UV resistance with a 20-year weathering warranty, ideal for exposed applications
- PVC: a cost-effective option for non-exposed, non-potable applications
- Installation: Our CAL-OSHA trained crews handle confined-space entry, liner placement, and fitting connections. The liner drops into the existing tank shell, and your tank is back in service in days, not weeks or months.
For more detail on how liner materials compare, see our material specifications page.
When to Repair a Leaking Tank vs. Replace It
Not every leaking tank needs a liner, and not every tank is worth saving. Here is a practical framework:
A liner makes sense when:
- The tank shell is structurally sound but no longer watertight
- The tank is larger than 3,000 gallons (replacement costs escalate with size)
- Downtime must be minimized, you cannot take the tank offline for months
- The tank has heritage or historical value (common with redwood tanks)
- Budget is a concern, a liner typically costs a fraction of full replacement
Replacement may be necessary when:
- The tank structure itself is failing, walls buckling, foundation compromised
- The tank no longer meets current safety or regulatory standards
- The tank is small enough that replacement is comparable in cost to relining
We cover the full decision framework in our blog post on tank repair vs. replacement. Not sure which path is right? Our team can take a look at your tank and give you a straight answer.
Why Municipalities and Water Agencies Choose Carson Liners
Carson Liners has been the trusted source for custom-fabricated tank liners for more than 45 years, serving municipalities, mutual water companies, farms, wineries, and rural water agencies across the Western United States.
- NSF/ANSI 61 certified materials approved for potable water contact
- ANSI/AWWA D130 compliant for geomembrane materials in potable water applications
- CAL-OSHA confined space and fall protection trained installation crews
- Family-owned, certified small business: you work directly with the people who build your liner
- No middlemen: we fabricate in-house and install with our own crews
Whether you have a concrete municipal reservoir with hairline cracking, a steel agricultural tank corroding at the seams, or a historic redwood tank that needs new life, we have done this work hundreds of times.
Get a Quote for Your Leaking Water Tank
Stop losing water and money to a leaking tank. Contact Carson Liners for a free assessment and quote.
Call us: 800-423-2380
Email: sales@carsonliners.com
Not sure what you need? Read more about our water tank liner solutions or browse our blog to learn why water tank liners are the best solution for a leaky tank.