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Buying Land on the San Mateo Coast: Permits, Water and Growth Limits

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

A lot on the San Mateo coast is only as valuable as the permits it can get. Development in the Coastal Zone needs a Coastal Development Permit or an exemption, issued under the County’s Local Coastal Program for unincorporated communities such as Montara, Moss Beach, El Granada, Pescadero and San Gregorio, or under the City of Half Moon Bay’s own program inside city limits. Before you buy, confirm three things for the specific parcel: whether it is in an urban or rural area under the plan, whether water and sewer service is actually available, and whether a growth allocation is needed to build.

Coastside land listings rarely explain any of this. This guide sets out the rules that decide whether a lot can be built on, using the County’s adopted Local Coastal Program policies, California Coastal Commission staff reports and the water districts’ own information. Policies change and district capacity changes, so treat it as a checklist for questions to answer during your investigation period, not as a ruling on any parcel.

Coastside Land homes for sale

Coastside Land market report

Who issues the permits: County or City

San Mateo County’s Local Coastal Program (LCP) was approved by the Board of Supervisors and the Coastal Commission in late 1980, and the County took over carrying out the Coastal Act, including issuing Coastal Development Permits, in April 1981. All development in the County’s Coastal Zone needs a permit or an exemption, and a permit can be issued only if the project complies with the LCP’s policies as well as the County’s zoning, building and health codes.

Half Moon Bay is an incorporated city with its own coastal program and its own growth limit, so a lot inside city limits follows city rules, while El Granada, Princeton, Miramar, Montara and Moss Beach to the north and the South Coast communities follow County rules. Our unincorporated San Mateo County guide explains how to tell which agency answers for a parcel.

Area	Planning authority	Water	Growth control
Half Moon Bay	City of Half Moon Bay	Coastside County Water District	Measure D certificates
El Granada, Princeton, Miramar	San Mateo County (Midcoast LCP)	Coastside County Water District	Midcoast limit of 40 new homes a year
Montara and Moss Beach	San Mateo County (Midcoast LCP)	Montara Water and Sanitary District, or a private well	Midcoast limit of 40 new homes a year
Pescadero, San Gregorio and rural lands	San Mateo County (LCP rural policies)	Usually a private well or small system; confirm	Density credits under Measure A policies

Urban Midcoast versus the rural coast

The County’s Midcoast Land Use Plan draws an urban/rural boundary and directs new development into existing urban areas and rural service centers, with infill of existing residential subdivisions and commercial areas. A lot inside the urban boundary is judged mainly on its zoning, its utilities and the growth limit. A parcel outside it is judged on rural policies that are much stricter.

Density credits on rural land

Outside the urban areas, LCP Policy 1.8 requires density credits for new or expanded non-agricultural uses, with exceptions such as affordable and farm labor housing. Table 1.3 sets how much land earns one credit, for example:

one credit per 160 acres of prime agricultural land;
one per 80 acres of land with slopes of 30% to 50%;
one per 60 acres in the 100-year floodplain; and
one per 40 acres of all other land.

Policy 1.8(a) also allows new rural development only if it will not significantly harm coastal resources or diminish the ability to keep agricultural land in production. A 20-acre parcel on the South Coast may therefore have no density credit for a new house at all. Ask the County how many credits a parcel has, and whether any were used or transferred, before you price it as a building site.

Measure A: rules only the voters can change

San Mateo County voters approved Measure A, the Coastal Protection Initiative, on November 4, 1986, and the Board of Supervisors put it into effect on April 26, 1988. In the LCP, Measure A policies are marked with an asterisk. They include the rural density rules in Policies 1.7, 1.8 and 1.9, Table 1.3 and several related policies.

Under Policy 1.32(a), those policies can be amended or repealed only after approval by a majority of the voters of San Mateo County. A seller’s or neighbor’s belief that the rural density rules “might be loosened” is not a basis for paying more for rural land.

The Midcoast growth limit and substandard lots

LCP Policy 1.23(a) limits the number of new homes built in the urban Midcoast to 40 a year. Policy 1.23(d) lets certain affordable units, including second units, exceed the cap under conditions. The figure came out of the Midcoast LCP update: the County originally proposed 75 units a year, and the resubmittal that Coastal Commission staff recommended for certification in 2012 reduced it to 40, about 1%.

Lot consolidation in Seal Cove and Miramar

Coastside land is sometimes offered as a group of small adjacent mapped lots. Policy 1.21 requires contiguous lots in common ownership in residential subdivisions in Seal Cove (to reduce risk to life and property) and Miramar (to protect coastal views) to be consolidated. In practice, two or three adjacent lots sold as a package may be treated as one building site. The 2012 Commission staff report also notes a voluntary lot merger incentive in the County’s zoning and a direction to evaluate a mandatory lot merger program as part of a Midcoast transportation plan.

If the listing describes “two buildable lots,” ask the County planner in writing whether they are separate legal parcels, whether they must merge, and whether each can get water and sewer.

Water and sewer: the deciding question

LCP Policy 1.19 requires adequate water and wastewater capacity before development in urban areas can be approved, and Policy 2.8 reserves public works capacity for priority land uses. A lot without a confirmed water source is not a building site.

Coastside County Water District

The district serves the City of Half Moon Bay and the unincorporated communities of Princeton, Miramar and El Granada. Its new-connection page (last updated July 2025) handles new residential and commercial connections and water main extensions, and starts applicants with its “Checklist for Obtaining a Water Service Connection or Plan Review.” The page lists no connection charges, so ask the district for the current amount before you price a lot.

Connections can come with the land. The district’s fee schedule sets a $600 initial deposit, toward its administrative and legal costs, to transfer an uninstalled connection. Ask the seller whether the parcel already holds a purchased but uninstalled connection, and get the district to confirm it in writing. Coastal Commission staff reports from 2009 and 2012 described limited remaining connection capacity on the Midcoast. We have not found a current district figure, so don’t rely on those older numbers.

Montara Water and Sanitary District

The district serves Montara, Moss Beach and adjacent areas north of El Granada. For years its Public Works Plan did not allow new water connections; the district says it repealed that longstanding moratorium and was granted permission to serve new connections in 2013. It now issues connections together with the County Planning and Building Department for new and existing projects inside the urban zones, and says it is working to develop new wells.

Private wells remain part of the picture: a 2012 Coastal Commission staff report counted about 946 wells in the Midcoast, serving about 24% of existing homes. The district’s published pages do not state connection fees or current capacity, so ask it in writing what a connection requires for the specific parcel.

Rural parcels

Outside the districts, plan on a private well and an onsite septic system. Test the well’s yield and water quality and have the soils evaluated for septic before you rely on a house site. If you are buying an existing home rather than land, also check the sewer lateral rules; see our guide to San Mateo County sewer lateral requirements at sale.

Half Moon Bay’s Measure D and the 2026 Measure I

Inside city limits, Half Moon Bay’s Measure D, approved by voters in 1999, limits residential growth by issuing a limited number of residential allocations each year. The city describes those allocations as split between the downtown area and the rest of the city, so where a lot sits on the Measure D map can affect its wait for an allocation.

Measure I, on the November 3, 2026 city ballot, would change that map. According to the city’s Measure I information page, it would replace the Measure D “Downtown Area” map, based on the 1998 Redevelopment Survey Area, with the “Town Center” area of the city’s 2020 Local Coastal Land Use Plan. The city says it would not change the location, density or intensity of development the plan and General Plan allow. It would also need California Coastal Commission certification before taking effect, and if it fails, the existing map continues to apply.

The City Council placed Measure I on the ballot on June 2, 2026. The San Mateo Daily Journal’s report on that vote said the change would affect 491 parcels, 326 of them residential. The result wasn’t known when this page was reviewed, so check the outcome with the city or the county elections office, then ask the city how the map applies to your parcel and how long the allocation wait is.

A buildability checklist for a Coastside lot

Confirm jurisdiction and zoning with the County or the City of Half Moon Bay, including whether the parcel is inside the urban boundary.
Confirm the legal parcel. Get a title report and ask whether contiguous lots must be merged under Policy 1.21.
Get water in writing. A will-serve letter or written connection requirements from the district, or a successful well test for a private well where allowed.
Confirm sewer or septic. District sewer capacity or a septic feasibility study.
Check the growth allocation. Midcoast: how the 40-unit annual limit is being allocated. Half Moon Bay: Measure D certificate availability.
Check rural density credits on any parcel outside the urban areas.
Map the hazards. CAL FIRE’s State Responsibility Area fire hazard maps took effect April 1, 2024 and its Local Responsibility Area maps were released in early 2025; check both, plus flood, tsunami, bluff and fault mapping in the natural hazard disclosure report.
Budget for the Coastal Development Permit: time, studies and the possibility of an appeal to the Coastal Commission on some projects.

Keep these answers in writing in one file for the lender and the next buyer. Our land development guide covers lot splits and state housing laws, many of which apply differently in the Coastal Zone.

Transfer tax on Coastside land

San Mateo County’s documentary transfer tax is 55 cents per $500 of value, which the County Clerk-Recorder states as $1.10 per $1,000. The recorder’s page names the City of San Mateo as adding its own tax. Ticor Title’s 2026 customary practices guide lists only the City of San Mateo and Hillsborough as city taxes in the county, and neither source shows one for Half Moon Bay.

So for a lot in Half Moon Bay or the unincorporated coast, expect only the county tax: $1,650 on a $1,500,000 sale, on our arithmetic. Ticor lists the county tax as a seller cost by custom, but custom varies and the purchase agreement controls. Confirm the figure with escrow, and see our California transfer tax guide for other counties.

Selling Coastside land

Buyers discount uncertainty. If you are selling a Coastside lot, gather the evidence before you list: the parcel’s legal description and whether it merges with neighbors, any will-serve letter or connection history, well tests, septic studies, any prior permit applications and the County’s or City’s written comments. A lot with documented water and a clear permit path will draw a different buyer than one sold as “potentially buildable.”

This is general information, not legal advice; talk to a California land use attorney or the planning department about a specific parcel.

Questions people ask

Do I need a Coastal Development Permit to build on the San Mateo coast?

Almost certainly. All development in the County’s Coastal Zone needs a Coastal Development Permit or an exemption, and Half Moon Bay applies its own coastal program inside city limits.

Can I get a water connection in Montara or Moss Beach?

Possibly. The Montara Water and Sanitary District lifted its connection moratorium in 2013 and issues connections with the County’s Planning and Building Department for projects inside the urban zones. Some Midcoast homes still rely on private wells. Get written confirmation of the requirements and fees for the specific parcel.

How many new homes can be built in the Midcoast each year?

Policy 1.23 of the County’s LCP limits the urban Midcoast to 40 new homes a year, with exceptions for certain affordable units and second units.

What is Measure A on the San Mateo coast?

A countywide initiative approved on November 4, 1986 that wrote rural density and land protection policies into the LCP. Those policies can be changed only by a majority vote of county voters.

Are adjacent lots in Moss Beach or Miramar separate building sites?

Not necessarily. Policy 1.21 requires contiguous lots under common ownership in residential subdivisions in Seal Cove and Miramar to be consolidated. Ask the County about the parcels you are considering.

How does Half Moon Bay limit growth?

Through Measure D, approved by voters in 1999, which issues a limited number of residential allocations each year, split between the downtown area and the rest of the city. Measure I, on the November 3, 2026 ballot, would redraw the downtown map. Confirm the result and how long the allocation wait is with the city.

Is there a city transfer tax in Half Moon Bay?

We found none. The San Mateo County recorder names only the City of San Mateo as adding a city tax, and Ticor Title’s 2026 guide lists only San Mateo and Hillsborough. On the coast, expect the county’s $1.10 per $1,000; confirm with escrow.

Can I build a house on agricultural land near Pescadero?

Only if the parcel has the density credits the LCP requires and the development will not harm coastal resources or the land’s agricultural use. Many rural parcels have fewer credits than buyers expect.

Weighing a lot in Half Moon Bay, El Granada, Montara, Moss Beach or the South Coast? Talk to us before you write an offer, and we will help you line up the questions for the planner, the water district and your inspectors. For the county as a whole, see our San Mateo County real estate guide.

Sources & notes

Last reviewed October 2026 by Matthew Martinez.