Tucson multifamily investment guide

Every other market in this series is constrained by zoning, by tax, or by rent regulation. Tucson is the one where the binding constraint on new housing is physical, and where the statute that imposes it happens to fall on an owner's competition rather than on the owner.

Section 45-576 of the Arizona Revised Statutes is titled "Certificates of assured water supply; designated cities, towns and private water companies." It requires a person who proposes to offer subdivided lands for sale or lease in an active management area to obtain a certificate before the subdivision documents are filed, and provides that a city, town or county "may approve a subdivision plat only if" the subdivider has obtained either a certificate of assured water supply or a written commitment of water service from a designated provider. The state real estate commissioner may issue the public report that authorises sales only on the same condition.³

The substantive test is the striking part. An assured water supply requires that "Sufficient groundwater, surface water or effluent of adequate quality will be continuously available to satisfy the water needs of the proposed use for at least one hundred years." Not ten years, and not the term of a construction loan. A century.³

Now the provision that decides whether this is a cost to an apartment owner or a benefit. Section 32-2101 defines "subdivision" or "subdivided lands" to mean land divided or proposed to be divided for sale or lease "into six or more lots, parcels or fractional interests," and the same definition expressly excludes "the leasing of agricultural lands or apartments, offices, stores, hotels, motels, pads or similar space within an apartment building, industrial building, rental recreational vehicle community, rental manufactured home community, rental mobile home park or commercial building."⁴

Put the two together. The hundred-year water certificate is a condition of approving a subdivision plat. An apartment building on a single parcel is not a subdivision within the statutory definition, and the leasing of apartments is expressly outside it. The test that gates new for-sale housing in this county does not gate the rental building that competes with it.

We want to be precise about the limit of that, because it would be easy to overstate. This does not mean an apartment is outside Arizona water law. A rental building still takes service from a water provider, and whether that provider is itself designated as having an assured supply under the same section is a real question at the utility level. What the statute does is attach the certificate requirement to the plat. An investor should read this as a constraint that falls asymmetrically, not as an exemption.³

• A plat may be approved only with a certificate of assured water supply or a written commitment of service.
• The test is a hundred years of continuously available water of adequate quality.
• A subdivision means six or more lots, parcels or fractional interests.
• The leasing of apartments is expressly excluded from that definition.

The hundred-year water test gates the for-sale subdivision that would compete with your building. It does not gate your building.

The demographic picture here is a milder version of a pattern this series has found repeatedly, and the gap between the two figures is the useful part.

Pima County grew 3.0 percent between April 2020 and July 2025, adding 31,254 residents. The City of Tucson grew 1.1 percent over the same period, adding 5,773. So roughly five sixths of the county's growth landed outside the city limits.²

That is not the collapse we recorded in Portland or Memphis, where the core lost residents outright. Tucson is growing, just slowly, while the periphery grows faster. For an owner of urban rental stock that is a workable position rather than a deteriorating one, provided the pricing reflects it.²

The city is where the renters are. Tucson is 51.8 percent owner-occupied, so 48.2 percent of households rent, against 34.8 percent across Pima County as a whole. The city also carries the weaker household base: median household income of $57,073 against $70,315 county-wide, and a poverty rate of 18.9 percent against 13.8 percent.²

Affordability is comfortable at the county level and tighter in the city. County median rent of $1,212 takes about 20.7 percent of median household income on our arithmetic. City median rent of $1,145 takes about 24.1 percent of the lower city income. Neither figure is stressed, and both leave more headroom than the 27.4 percent we measured in Memphis or the 35.9 percent in the Bronx.²

Supply is moderate. Pima County permitted 4,658 residential units in 2025 against a stock of 497,065, about 0.94 percent. Census publishes permits and housing unit counts for the county rather than the city here, so we do not split that figure. Set against the water constraint described above, a permit rate under one percent is what you would expect in a county where new subdivisions face a hundred-year proof and the growth is on the periphery.²

• Pima County added 31,254 residents; the City of Tucson added 5,773.
• The city is 48.2 percent renters against 34.8 percent county-wide.
• City median household income is $57,073 against $70,315 county-wide.
• Permits ran about 0.94 percent of county stock in 2025.

Five sixths of the county’s growth landed outside the city limits, but the city did not shrink. That is a workable position, not a deteriorating one.

Our position on Tucson is moderately constructive, and it rests on the asymmetry of the water rule more than on the growth numbers.

We would underwrite the university corridor and the established midtown submarkets. This is where the renters are in a city that is 48.2 percent renter-occupied, it sits beside the largest and still growing supersector in the metro, and rent at roughly 24 percent of city median income leaves genuine headroom. The Arizona tax position, no municipal tax on residential rent and no assessment penalty for renting, is a real contribution to net operating income rather than a talking point.²

We would also look at Oro Valley and the northern county, where household incomes are materially above the city and where the county's growth is actually landing. The qualification is that the county is 65.2 percent owner-occupied, so the rental base outside the city is thin and product is scarce.²

We would not buy peripheral product in Vail or the far southeast. That is where for-sale development competes most directly, the rental base is thinnest, and the household profile is furthest from a rental thesis.²

The risk we would size explicitly is the government payroll. Government is about 17.6 percent of payrolls here and it is contracting at 2.3 percent a year. For any specific rent roll we would want to know what share of tenants are employed by federal, state or local government, and we would stress that share against budget contraction rather than against a general recession, in the same way we would stress a Memphis rent roll against freight.¹

On the water question our advice is the opposite of alarm. For an owner of existing rental stock, a hundred-year assured supply requirement that applies to subdivision plats and not to apartment leasing is a structural constraint on competing for-sale supply. We would treat it as a durable reason that new single-family competition arrives slowly in this county, and we would confirm the water service position of any specific asset at the provider level rather than assuming the statute settles it.³⁴

A hundred-year water proof that binds subdivisions and not apartment leasing is a structural brake on your competition. Confirm the provider position on your own asset rather than assuming the statute settles it.