Every week, someone buys a mobile home park and discovers the same thing three months later: they’re losing thousands of dollars a month on a water bill that should cost half as much, or they’re staring at a $200,000 sewer main repair that wasn’t in the pro forma.

This isn’t bad luck. It’s a due diligence failure — and it’s one of the most consistent value destroyers in the manufactured housing space.

At Keel Team, we’ve evaluated hundreds of communities across the Southeast and Midwest. Infrastructure problems — specifically aging water and sewer systems — are the single most common reason a “good deal” turns into a difficult hold. Here’s what we’ve learned.

Why Old Parks Have Old Problems

The majority of manufactured housing communities in the US were built between the 1950s and 1980s. That’s 40–70 years of pipe under the ground. The sewer mains in many of these communities are clay tile — a material that works reasonably well until it doesn’t. Once root intrusion starts or sections begin to collapse, the deterioration tends to accelerate.

Water mains are often worse, because you can’t camera them. Many older communities have 1.5 to 2-inch diameter water mains that were sized for a different era — before residents had dishwashers, washing machines, and high-pressure showers. The result is chronic low water pressure that generates constant resident complaints and maintenance calls.

The 125-Gallon Rule

Here’s a quick benchmark every mobile home park buyer should know: if a community’s total water usage averages more than 125 gallons per resident per day, there are active leaks somewhere in the system.

Pull 12 months of master water bills during due diligence. Divide total monthly usage by resident count and by 30 days. If you’re consistently above 125, budget for a problem — not a maybe, a certainty.

In our experience, a single running toilet left undetected can consume 20,000+ gallons per month. Multiply that across 10 homes and you’re looking at $1,500 to $3,500 in lost NOI every month. Annualized, that’s enough to materially move a cap rate.

The Submeter Misconception

Water submetering has become standard practice in well-run communities, and for good reason — it allows owners to bill residents directly for their usage, and it creates accountability that reduces consumption by 25–30% on average. ROI is typically under 12 months at roughly $300 per home for installation.

But submeters don’t fix everything. If there are leaks in the park’s main infrastructure — upstream of the individual home meters — that water is still being lost and still being billed to the park at the master meter. Submeters tell you what each resident is using; they don’t stop the main line from leaking before the split.

The lesson: submeter your community, absolutely. But do your water infrastructure audit first. Know what you’re working with.

What a Real Infrastructure Audit Looks Like

Before closing on any community, here’s the checklist we run at Keel Team:

1. Pull 12 months of master water bills. Calculate gallons/resident/day. Flag anything above 125.
2. Hire a licensed plumber to scope the sewer mains with a camera. Clay tile, condition of joints, root intrusion — all visible. This typically costs $500–$1,500 and is money well spent.
3. Review water main size and material. Ask the seller or county utility records. Anything under 2” diameter in a community of 50+ lots is a red flag.
4. Check the age and condition of lift stations (if applicable). Pump failures are expensive and urgent.
5. Get utility bills, not estimates, from the seller. Request actual bills, not a pro forma number.
6. Ask about past infrastructure repairs. What broke? When? What was fixed? What’s still deferred?

If the seller can’t provide this documentation, that tells you something important. For a comprehensive framework covering infrastructure, legal, and financial due diligence, our Mobile Home Park Due Diligence Playbook covers this checklist in detail alongside the full acquisition evaluation process.

Pricing Infrastructure Risk Into Your Model

Even if the infrastructure looks manageable, the smart move is to build a dedicated reserve into your operating model. We target $200–$400 per lot per year in infrastructure reserve, depending on the age and condition of the community. For a 100-lot park, that’s $20,000–$40,000 per year set aside before you ever see a sewer emergency or a main break.

This isn’t pessimism — it’s operational discipline. The parks that get hurt are the ones that assume the infrastructure will hold because it held through the seller’s ownership. It may not hold through yours.

The Bigger Picture

Mobile home park investing has a lower barrier to entry than multifamily, but it comes with its own version of complexity — and underground infrastructure is chief among them. If you’re earlier in your research, our mobile home park investing 101 guide covers the full landscape before you get into advanced due diligence. The operators who consistently outperform aren’t necessarily smarter; they’re more systematic. They use checklists. They run the numbers before they close. They price risk rather than ignore it. For a step-by-step framework on how to value what you’re buying, our guide to how to value a mobile home park walks through the full NOI and cap rate analysis.

At Keel Team, we’ve built our acquisition process around exactly this kind of rigor. It’s why we’ve been able to operate communities across multiple states without the infrastructure surprises that catch others off-guard.

The underground is where the deal is made or broken. Don’t skip it.

Keel Team is a manufactured housing community investor and operator based in Mooresville, NC, with communities across the Southeast and Midwest.