Picture a cabin above Twain Harte Drive in a January when nobody comes up. The thermostat is set low, the faucets are off and the driveway hasn't been plowed. The utility bill still comes every month, and it's almost exactly what it would be with a family living there.
Most of Twain Harte gets its water and sewer from the Twain Harte Community Services District. The district prices both services so that the fixed charges make up nearly the whole bill. If you're comparing towns along Highway 108 for a second home, this cost doesn't change with how often you visit, and it doesn't show up next to the price on a listing sheet.
A small utility with its own treatment plant
Twain Harte's system differs from many mountain towns', where wells and septic tanks are the norm. The district buys raw water from Tuolumne Utilities District, or TUD. That water is stored in Lyons Reservoir and reaches the district through an open ditch. The district treats it at its own plant, which can process one million gallons a day, and sends it through about 27 miles of pipeline to roughly 1,600 customers. On the sewer side, the district runs about 25 miles of mains and three lift stations, and all the wastewater it collects goes to TUD for treatment. The Sherwood Forest subdivision is the only part of the district that uses individual septic systems.
So the district buys raw water and pays for sewage treatment from another agency, and it also maintains a treatment plant, tanks, pump stations and miles of pipe. Those costs stay the same whether a house is full or empty, and the district's rates are set up the same way.
The floor under every bill
The district's board adopted five-year water and sewer rate schedules on January 10, 2024, based on its 2023 Water & Sewer Rate Study. Here's what that schedule means for a single-family home in fiscal year 2026-27, which runs through next summer:
- Water base charge: $73.62 a month, fixed.
- Sewer demand-flow charge: $79.25 a month for each equivalent single-family residence, or ESFR. A typical house counts as one ESFR.
- Water use: $3.36 per 1,000 gallons for the first 2,000 gallons and $4.61 per 1,000 gallons after that. These rates took effect July 15, 2026.
The rate study describes the sewer charge as a fixed monthly charge based on the typical wastewater flow for each customer class, not on what a particular house actually sends down the drain. The two fixed charges add up to $152.87 a month, or about $1,834 a year, before the tap is ever turned on.
Compare that with a full-time household using 4,000 gallons in a month. Its water use adds $15.94, for a total bill of $168.81. A cabin that sits empty all month pays about 91% of what that household pays. Living in the house adds about $16 to the bill. Owning it accounts for the other $153.
What the code says about an empty house
The district's Water Code, Ordinance 31, covers vacant homes directly:
A customer account will be billed whether or not the property is vacant, or water is being consumed. No credit or discount will be allowed or approved for any vacant properties regardless of the reason for the vacancy.
The code allows only one suspension. At the general manager's sole discretion, the district can suspend monthly charges for up to six months when a catastrophic event, such as a fire, makes a home uninhabitable, and only for customers who have kept their service active for at least a year. A quiet winter doesn't qualify. The Wastewater Code, Ordinance 32, has the same rules for sewer: it bills vacant properties, gives no credit for vacancy, and allows the same narrow suspension after a catastrophe.
Utility codes are written this way for a reason. In a town with many part-time owners, a vacancy credit would push the cost of the treatment plant and the pipes onto the people who live there year-round. With the fixed charges as written, every connection pays its share of the system whether or not anyone is using it.
A lot with no meter can still get a bill
The same section of Ordinance 31 matters for anyone looking at land. Water charges go to customers who receive service, and also to anyone who has "capacity allocated to the property, regardless of whether a service lateral or meter has been installed." That means an undeveloped lot with capacity already assigned can come with a monthly bill. A lot without assigned capacity, on the other hand, will need connection charges before anything is built. The district currently lists residential water connection charges of $1,000 if a service stub is already in place and $3,000 if not. Sewer connection is $700 with a stub and $2,900 without.
In both cases, a vacant parcel inside the district comes with a utility cost, either as a monthly bill or as connection charges, that a buyer should find out about before making an offer.
The provider depends on the address
A "Twain Harte" mailing address doesn't guarantee service from the district. Some neighborhoods nearby are TUD retail customers. In 2020, for example, TUD crews repaired a water main on Robin Road in what TUD called the Brentwood Park subdivision in Twain Harte. TUD prices its water a little differently, but its bill is also mostly fixed.
| Monthly, single-family home | Twain Harte CSD, FY 2026-27 | TUD, effective July 1, 2026 |
|---|---|---|
| Fixed water charge | $73.62 | $87.79 for a meter of 1 inch or less |
| Water included in fixed charge | None | First 400 cubic feet, roughly 3,000 gallons |
| Fixed sewer charge | $79.25 per ESFR | $69.76 |
| Combined fixed floor | $152.87 | $157.55 |
| Vacancy credit on water | None | None |
TUD's water rules apply its fixed charge "irrespective of quantity used." Its suspension rule is also limited to catastrophic events. It requires one year of prior service and allows up to six months, plus up to three more months for documented reconstruction delays. The two providers differ a bit in their fixed charges, but under either one a part-time owner pays about $150 to $160 a month before any water is used.
The next increases are already on the calendar
These amounts will go up. The district's schedule raises the single-family water base charge to $76.16 and the sewer charge to $83.85 per ESFR in fiscal year 2027-28. Those increases take effect July 15, 2027, and bring the combined fixed charges to $160.01 a month. TUD's fixed water charge goes to $89.11 on July 1, 2027. Part of the district's cost comes from TUD. The district's FY 2026-27 budget attributes its higher purchased-water and sewer-service costs to TUD rate increases, and the published TUD schedule raises the sewer treatment charge it bills the district to $33.31 per ESFR in July 2027.
The district's October 14, 2026 general manager's report lists the work these fixed charges help fund:
- Cresta sewer replacement, $325,000. Crews have replaced 955 feet of high-risk line between Cresta Drive and Oak View Drive. The remaining 1,550 feet is due for relining in spring 2027.
- Twain Harte Drive to Marquis Drive, $160,000. This project will repair and reline 900 feet of sewer line along with the Cresta work.
- Cedar Pines pressure-zone upgrades, $700,000. The district is hiring a consultant to design the project, which will remove an aging tank and pump station and replace deteriorated, undersized water lines.
- SCADA improvements, $645,000. This system will let the district monitor and control its treatment plant, pump stations, tanks and lift stations remotely. The district is waiting on grant funding to start.
The current schedule runs through fiscal year 2027-28, so a buyer closing this winter is buying under rates that are set for about the next two years. After that, there is no published schedule yet.
TUD is building a separate plant of its own nearby. Its $45.6 million Sierra Pines Regional Water Treatment Facility at 23908 South Fork Road broke ground June 26. It will consolidate six TUD plants: Cedar Ridge, Crystal Falls, Lakewood, Phoenix Lake Park, Ponderosa Hills and Scenic View. The district's own treatment plant isn't one of them. According to TUD's October update, hydroseeding at the site is scheduled for October 19 through 25, and major construction is expected to begin in 2027.
Questions to settle before you write an offer
- Which agency serves this address? Confirm water and sewer service with the district or TUD for the specific parcel. If the home is in Sherwood Forest, ask about the septic system.
- What will the house cost each month, empty? Use the fixed charges above and check them against the seller's recent bills. For a rental, put this figure in the expenses for every month of the year, booked or not.
- Does a vacant lot already have capacity assigned? That decides whether you'll get a monthly bill now or pay connection charges later.
- Should you look inside the sewer lateral? The district's miscellaneous fee schedule, last amended May 13, 2026, lists $150 for a private sewer-lateral camera inspection and $30 to set up or transfer an account.
This post is general information, not legal or financial advice. Confirm your own situation with the utility and the right professional before you rely on any number here.
FAQ
Can I shut off water to my Twain Harte cabin for the winter and stop the bill? Under the district's Water Code, vacant properties are still billed and there's no vacancy credit. The only suspension the code provides is after a catastrophic event that makes the home uninhabitable. Ask the district how this applies to your account.
Is the sewer charge based on how much water I use? No. In the district, the sewer charge is a fixed monthly amount per ESFR, based on typical flow for each customer class.
Will the Sierra Pines plant lower my bill? Sierra Pines is replacing six TUD treatment plants. The district treats its own water at its own plant, which isn't part of that consolidation.
When I look at a Twain Harte property with a client, the utility bill goes into the budget alongside the roof and the septic or sewer lateral, because it's a cost of owning the house whether or not anyone stays there. If you'd like help figuring out what a specific cabin or lot will cost you each month before you make an offer, Vass Haus RE can walk through it with you. Schedule a Free Home Valuation & Consultation.
