On the Coherency of Transects and Urban Growth Boundaries - Part Two

In my last post, I gave the background for a land-use conundrum that has arisen in Petaluma.  The regional rail authority, SMART, is reportedly pursuing a land swap that would accelerate development of a second train station in Petaluma and of transit oriented development adjoining the first Petaluma train station.  Both are fine goals.  But the swap would put the second station at the urban fringe, a location bothersome to local urbanists.

Today, I’ll fill in more of the site and regulatory background, along with reintroducing an urbanist concept that speaks directly to the concern.  In my next post, I’ll conclude with my personal conclusions and philosophical insights.

The new site for the second station is within, but immediately adjoining the Urban Growth Boundary, the current legal barrier to further urban development.  A UGB can be realigned, but the process is slow and onerous.

Even importantly, the site adjoins a Community Separator, a set-aside area that is intended to be permanently excluded from UGBs in order to maintain rural lands between cities.  Over time, it’s expected that the UGB will move as the City of Petaluma needs more land.  But however much expansion might be desired, the Community Separator is intended to remain forever off-limits.

(The photo is of the Community Separator from an office window a short walk from the proposed train station.  Note the train tracks in the foreground.)

The result is that that station location, a former lumber yard that has been vacant and awaiting a new use for a decade, may provide a readily available site for transit use, but is trapped in a corner with little adjoining room for related development.  To the west and north are expansive office parks.  To the east is the Community Separator that is a permanent barrier to future development.

It’s only to the north that a small strip of developable land remains, between Old Redwood Highway and the railroad tracks.  And even that land is outside of the UGB, so is likely to remain barred from development for many years.  (The site can also be viewed here.  The station site is where the three parallel sheds are located, near the middle of the map.  The land east of the curved rail alignment is in the Community Separator.  And the light industrial and sales land uses north of the site are outside the UGB.)

Those who view the world through drivable suburban spectacles may argue that developable land isn’t needed around the station, that the downtown station will provide a walkable urban setting for those with that preference, and that the only function of the second station should e to provide parking for those who would drive, which the newly proposed site accommodates well.  (Although even the drivable suburban devotees may pause at having the station at the far north end of town, resulting in more traffic on busy McDowell Boulevard and undersized Ely Road.)

But the bigger concern should be the continual reports from surveys of potential homebuyers, especially among the younger segments of the population, that they want more walkable residential options.  It’s a topic about which I most recently wrote here.  With a transit station being a logical focus of a walkable setting, siting a transit station where only limited residential land is available, and even that land requiring a UGB realignment, would be a land-use decision that doesn’t address the long-term needs of the community.

One of the underlying theories of urbanism, the concept of transects, also shines a light on the shortcomings of the possible station location.  The transect theory, which is borrowed from biology, argues that cities, like biological communities, are more stable and functionally effective when they transition gradually and logically between areas of different function and intensity.

In biology, a transition might be from a surf line to a sandy beach to a grass-covered coastal dune to a coastal forest.

In land-use, the transition is usually depicted as from natural land (Transect 1 or T1) to rural agricultural land (T2) all the way to the most intense urban uses (T6).

Train stations, with their parking and/or transit oriented development adjacencies, should probably never occupy any Transect below T4.  The downtown Petaluma station is adjoined by T5 and T6.

But the Community Separator on the far side of the rail tracks from the proposed station site is realistically a T2, if not a T1.  So we would have a T4 use immediately adjoining an area of T1/T2.  Mother Nature wouldn’t do that and perhaps neither should we.

Balanced against all of these concerns is the reality that the newly proposed site is available for immediate development, unlike the site that was formerly proposed for the second station.  Also, the site adjoins office parks to which workers could perhaps travel by train.  As a legitimate goal for urbanists is a functioning and productive transit system, the second site therefore has attractions to the urbanist mind.

The question becomes whether to accept a flawed land-use pattern in exchange for a train station that will be available more quickly, following the dicta of not letting the perfect become the enemy of the good, or to insist on waiting until a train station site becomes available that would result in a better land pattern.

In the next post, I’ll offer the result of my mental balancing on the question, along with some related musings about the relationship between transects, UGBs, and Community Separators, the “coherence” promised by the title of these posts.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)