A Dillon Beach ownership budget should identify the actual water provider, wastewater arrangement, property obligations and work needed. A mortgage estimate leaves those questions unanswered. Even within Oceana Marin, the organization supplying water and the district collecting sewer charges need to be identified separately. A Village home with septic requires a different evidence file from a house connected to district sewer.
The Dillon Beach guide introduces the community’s service differences. This article develops an annual worksheet and three hypothetical partial utility examples using current public rates checked October 25, 2026. Read it with the Marin County guide and the financing guide when evaluating purchase costs. No household bills, insurance quotations or contractor estimates were supplied; the examples are not complete ownership budgets or actual customer accounts.
Put each bill on the correct property and period
Request the current secured tax bill, utility statements, association documents if applicable and available maintenance records. Match the parcel number and service address, then record each billing period. Separate recurring costs from deposits, overdue balances and one-time work. Where a purchase includes multiple parcels or separate accounts, keep each visible rather than assuming the street address describes a single set of obligations.
Annualize only after identifying the billing cycle and effective dates. Six equal two-month periods and twelve equal monthly periods are different calculations. A current-rate illustration holds prices constant; it is not a reconstruction of calendar 2026 or a forecast of future increases. Keep rate changes, consumption assumptions and costs still needing quotes beside the worksheet so the reader can reproduce the subtotal.
Start with the actual water provider
Estero Mutual’s current residential rate page lists operations of $287.22 and reserves of $81.08 per two-month billing period, a fixed subtotal of $368.30 before metered use. The company measures usage in gallons and identifies an every-other-month billing cycle. Confirm the actual account and current schedule before using this structure for a property; the provider does not serve every Dillon Beach home.
For a clearly hypothetical 4,000 gallons in each billing period, the listed first-band rate of $0.00786 per gallon gives $31.44 in usage charges. Adding the fixed subtotal gives $399.74 per period; six identical periods give $2,398.44 in annual listed water charges. The model stays within the first usage band and assumes unchanged prices. It establishes neither typical consumption nor permission for an intended use.
Cal Water’s Coast Springs customers require a different calculation. The Redwood Valley tariff index links the current Bay Area Region residential schedule. Its October 1, 2026 filing includes Coast Springs-specific capacity provisions, meter charges and additional schedules. The document says effective subject to refund until final Commission approval. Do not substitute Estero rates or assume a generic water-use price is the complete Cal Water bill.
For a Cal Water-served property, obtain the actual meter size, applicable schedules and current account explanation before estimating the annual cost. Preserve the distinction between the tariff’s effective status and final approval. A small published base-rate example that excludes required surcharges would understate the question the buyer needs answered, so this worksheet does not manufacture a second provider’s total from incomplete account information.
Reconcile sewer charges with the tax bill
North Marin Water District’s current rates page lists the Oceana Marin sewer service charge at $1,724 per dwelling for July 1, 2026 through June 30, 2027, included on the property tax bill. Confirm the actual dwelling and connection. This is a sewer charge, separate from domestic-water service, and it should not be assigned automatically to a septic-served house.
Adding that annual sewer amount to the hypothetical 4,000-gallon Estero example gives a partial $4,122.44 for the two listed services. This combination is appropriate only where both connections are actually confirmed. If the tax-bill total already includes sewer, do not add $1,724 a second time. Either itemize it out of taxes or retain the full tax bill and add only the separately billed water amount.
Keep the utility’s reserve charge distinct from money the homeowner sets aside for private repairs. Estero’s listed reserve component is already included in its fixed water subtotal. A private house reserve might address the roof, drainage or other owner responsibilities, but it is not another label for the same utility fee. The worksheet should explain what each reserve funds and count each expenditure once.
The model also shows which inputs drive this particular subtotal. Six listed fixed water charges total $2,209.80 before usage. Within the first band, increasing the hypothetical consumption by 2,000 gallons in every two-month period adds $94.32 over six periods. That limited comparison helps the buyer see fixed and variable spending separately. It should not be extended into higher bands without applying their actual rules, and it does not suggest that using less water removes the fixed obligations. Check the real account’s periods, charges and consumption before substituting an annual estimate for the illustrative figures.
Original worksheet: listed utility charges and missing household inputs
Hypothetical partial model, checked October 25, 2026. Estero residential fixed charge: $368.30 per two-month period, including operations and reserves. All examples remain within the listed first usage band at $0.00786 per gallon. Six identical periods and unchanged rates are assumptions. Oceana Marin sewer adds $1,724 annually only for an actual connected dwelling. These are not complete bills or household budgets.
| Hypothetical use per two months | Usage charge | Fixed plus usage per period | Annual listed water charges | Partial annual water plus confirmed sewer |
|---|---|---|---|---|
| 2,000 gallons | $15.72 | $384.02 | $2,304.12 | $4,028.12 |
| 4,000 gallons | $31.44 | $399.74 | $2,398.44 | $4,122.44 |
| 6,000 gallons | $47.16 | $415.46 | $2,492.76 | $4,216.76 |
Sources: Estero current rates and NMWD fiscal 2026–27 sewer rate. Replace assumptions with actual account data. Sewer collected on the property tax bill must be counted only once. Cal Water, private wells and septic require their own entries.
| Category | Input still required | Avoid this shortcut |
|---|---|---|
| Tax and direct charges | Actual buyer estimate, current parcel bill and supplemental needs | Copying seller’s total or double counting sewer |
| Wastewater where septic applies | System records, evaluation, current permit/service obligations and quotes | Using the sewer amount as a septic budget |
| Insurance | Property-specific policies, premiums, limits and deductibles | Applying a coastal average or another house’s quotation |
| House, drainage and access | Inspection findings, ownership duties and scoped work estimates | Assuming an unpriced repair costs nothing |
| Association and shared duties | Applicable governing documents, current dues and actual assessments | Inferring fees or coverage from a subdivision name |
| Other services and capital work | Actual waste/energy arrangements, dated quotes and payment timing | Calling the partial utility subtotal a total ownership cost |
For septic, price the actual system rather than a substitute
Obtain the County file, installed-system description, evaluation and available maintenance records. Ask which recurring services and permits apply and what identified work needs further design or review. Marin County’s current septic program page distinguishes standard and alternative systems and identifies annual operating-permit and monitoring obligations for alternative systems. Obtain the actual service prices and applicable fees for the subject.
The County’s Village feasibility study is a separate community-planning record. Its alternatives and historical estimates are not current household invoices or an adopted parcel assessment. Ask for current information if a community project affects the purchase, but retain the home’s existing obligations until verified implementation and connection evidence establishes a different arrangement.
Use the buyer’s tax estimate and the actual ownership documents
The County’s supplemental-assessment explanation describes additional bills following qualifying ownership or construction changes. Obtain the appropriate estimate for the transaction and keep supplemental cash needs separate from ordinary annual payments. Reconcile lender escrow collections against the underlying bills rather than counting deposits and taxes as unrelated expenses.
Where association or shared responsibilities apply, obtain the governing documents, current financial information, dues and any actual assessment notices. Ask which structures or services the owner must maintain separately. A subdivision name, a utility reserve charge or an older neighbor’s payment does not establish the buyer’s obligations. Keep missing documents and unconfirmed amounts visible instead of filling them with a convenient neighborhood allowance.
Price insurance and maintenance from the property evidence
Request insurance quotations early using the actual address, buildings, intended occupancy and known features. Compare coverage forms, insured limits, deductibles and conditions alongside premiums. The Department of Insurance’s residential guide helps organize policy and separate-hazard coverage questions. The property’s exact quotation matters more to this worksheet than a generalized statement about coastal insurance.
Divide maintenance into the house, site drainage, retaining features, access and relevant private systems. Identify the responsible party before assigning a cost. For work requiring specialist assessment, obtain the scope and any needed design or agency review. A roof estimate, an engineering investigation and an access arrangement can be separate costs; ask the estimator what is included and which items remain outside the price.
Separate recurring care from an identified capital project and from money retained for unresolved conditions. Record the planned timing and dependencies so a comfortable annual average does not hide a large near-term payment. Compare the completed worksheet with funds remaining after closing and the buyer’s essential plans. Refresh current service rates and actual quotations before relying on the result, and leave the listed utility examples in their proper role as partial calculations.
