What Is a Will-Serve Letter and Why Your Project Can't Move...

A will-serve letter is a written statement from a utility provider — water district, sewer district, fire district, electric company, or gas company — confirming that the agency can and will provide service to your project. Without one, most planning agencies won't accept your entitlement application, and you won't get a building permit either.

If you've ever wondered why your project stalled at the tentative map stage or came back from the planning department with a request for "utility availability letters," this is what they're asking for. Understanding what's a will-serve letter, who issues them, and when to ask for them is one of the most practical things you can do to keep a project on schedule.

Who Issues Will-Serve Letters?

Each utility provider issues its own, and in California you typically need them from most or all of the following:

• Water district — confirms potable water supply and fire flow capacity. In Contra Costa County this might be EBMUD (East Bay Municipal Utility District) or CCWD (Contra Costa Water District). In the Tri-Valley area you're often dealing with DSRSD (Dublin San Ramon Services District).
• Sewer district — confirms wastewater collection and treatment capacity. CCCSD (Central Contra Costa Sanitary District) covers much of the central county. DSRSD handles sewer as well as water in parts of Dublin and San Ramon.
• Fire district — confirms adequate fire flow and, in some jurisdictions, hydrant coverage. CCCFPD (Contra Costa County Fire Protection District) issues these for unincorporated areas and several cities.
• Electric utility — PG&E for most of Northern California. Their letter typically confirms that they have capacity to extend service and that a Rule 15 or Rule 16 extension is feasible for your project size.
• Gas utility — also PG&E in most of the Bay Area. Gas will-serve letters are usually simpler than electric, some agencies still require them for entitlement packages.
• Telecom / broadband — less common, some jurisdictions now require confirmation from a broadband provider, particularly for subdivisions.

Your project may not need all of these. An all-electric project won't need a gas will-serve. A project inside a city limits might combine water and sewer under one agency. Check with your planner or your civil engineer before you start collecting letters — the list is jurisdiction-specific.

When Do You Need Them?

Will-serve letters show up at multiple stages in the entitlement and permitting process, and the requirements vary by jurisdiction. Here's where you'll typically need them:

• Tentative map / subdivision application — almost always required. The Subdivision Map Act requires that cities and counties make a finding of "sufficient water supply" before approving a tentative map, and the will-serve letter is how you satisfy that finding.
• Planning commission / design review — most planning departments in the Bay Area require utility availability letters as part of a complete entitlement package. Missing one will trigger an incompleteness letter and reset your clock.
• Environmental review (CEQA) — if your project triggers an EIR or MND, utility capacity is usually a topic of analysis. Having current will-serve letters in hand speeds up that process.
• Building permit — most building departments require water and sewer will-serve letters, or service connection agreements, before issuing a permit. Some also require PG&E confirmation. Don't wait until you're ready to pull permits to ask for these — that's a common mistake we'll cover below.

How to Request One

The process is similar across most utilities, though the forms and fees differ:

1. Contact the utility provider's new connections or developer services department. EBMUD has a dedicated developer services team. DSRSD has a connection application process. PG&E's Electric Rule 15 process starts with a project inquiry through their New Business portal.
2. Provide the project address and APN (Assessor's Parcel Number). Some agencies will also want the legal description or a site map showing parcel boundaries.
3. Submit a preliminary site plan and estimated demands. For water and sewer, this means estimated average daily demand, peak demand, and fire flow requirement. For electric, it means estimated connected load and service voltage. For gas, it means estimated peak demand in therms per hour. If you don't have detailed calculations yet, a preliminary estimate from your civil engineer is usually enough to get the letter started.
4. Pay the processing fee. Fees vary. EBMUD charges for capacity analysis reviews. PG&E charges for preliminary design estimates. Budget for it.
5. Wait. And that brings us to the part most developers underestimate.

How Long Does It Take?

A simple will-serve letter from a well-staffed district can come back in two to three weeks. That's the optimistic end. Four to six weeks is more typical for water and sewer agencies. PG&E's preliminary engineering estimate — which is what backs a will-serve for electric — runs six to twelve weeks for larger projects, and can stretch further if the project requires a substation study or transmission-level analysis.

The reason this matters is that entitlement completeness reviews often won't start the clock until all required letters are in hand. If you submit your planning application and EBMUD needs eight weeks to process your request, you've added eight weeks to your schedule before the planner has even opened your file.

What Triggers a Capacity Study vs. A Simple Letter?

Not every project gets a straightforward "yes, we can serve you" letter. The larger your project, the more likely you're to trigger a formal capacity analysis.

For water and sewer, the threshold is usually demand-based. A 200-unit apartment complex is going to add meaningful load to the system. The district needs to confirm that the existing mains, pump stations, and treatment capacity can handle it. If they can't, the letter comes back with conditions: you may need to fund a main extension, upsize a downstream pipe, or pay a capacity fee that covers a pro-rata share of a future plant expansion.

For electric, anything above a few hundred kilowatts of connected load typically requires PG&E to run a grid study. If the nearest substation is already loaded, you might be looking at significant infrastructure costs — and a timeline measured in years, not months. We've seen this derail projects in areas where grid capacity hasn't kept pace with development. Getting PG&E's preliminary estimate early, during due diligence, is one of the most important things you can do before you're committed to a site.

What If a Utility Can't Serve You?

It happens. The main is undersized. The pump station is at capacity. The transformer is tapped out. In that case, the utility's response isn't always a flat "no" — it's more often a conditional "yes, with these improvements."

Those improvements become your responsibility to fund. Common scenarios:

• Main extension — you pay to extend a water or sewer main from the nearest point of adequate capacity to your project frontage.
• Upsizing existing infrastructure — the existing main needs to be replaced with a larger pipe. You pay for the upsizing, often with some credit for the portion the district would have replaced anyway.
• Off-site improvements — sometimes the constraint is a downstream lift station or a connection that's a block or two away. You fund the improvement, and the district reimburses you as other projects connect and pay their capacity fees (these are called reimbursement agreements, and they take a while to collect).
• Capacity reservation fees — some agencies require a fee to reserve capacity before it's committed to another project. If your schedule is long, ask about this.

These costs are real and can be substantial. A main extension across a busy arterial can run $200,000 to $500,000 or more depending on depth, traffic control, and pavement restoration. This is exactly why utility feasibility belongs in your site planning and due diligence process — not in your budget contingency column after you've already bought the land.

Will-Serve Letters Expire

One more thing that catches developers off guard: will-serve letters have shelf lives. Most agencies issue them valid for one to two years. If your project slips schedule and the letter expires, you'll need to request a renewal — and the agency will reassess capacity at that time. If something has changed in the system since the original letter was issued, you could get a different answer, or a more expensive set of conditions.

Track your expiration dates and request renewals with enough lead time to not delay your permit.

The Mistake Everyone Makes

We see this constantly: a developer assembles a project team, spends months on architecture and planning, submits an entitlement application — and then someone asks for the will-serve letters. At which point the team realizes nobody requested them. The project goes incomplete. The schedule slips four to eight weeks while the letters catch up.

Request will-serve letters the same week you hire your civil engineer. It takes a few hours to prepare the request package, and the clock starts running immediately. By the time you have a site plan worth submitting, you'll have letters in hand.

That's the discipline that separates projects that move from projects that stall.

How We Handle This on Calichi Projects

Utility coordination is part of our standard site planning scope. We prepare the will-serve request packages, coordinate directly with EBMUD, DSRSD, CCCSD, CCCFPD, PG&E, and other agencies, track the response timelines, and flag capacity constraints before they become budget surprises. If a utility comes back with conditions, we help you understand what the off-site improvement costs actually are before you commit further resources.

If you've got a site in Contra Costa County, the Tri-Valley, or anywhere in the Bay Area and you want to know what utility service looks like before you're deep into design, give us a call. It's one of the fastest ways to validate — or rule out — a site.