Phoenix, Portland, and the Street Hierarchy

The latest edition of the High Country News just arrived in my inbox. They've published a nice piece on the experience and politics of walking in Phoenix compared to Portland. The piece is available online, but you have to subscribe to HCN to access the full text.


The major reason why people don't walk in Phoenix, according to the article, is a principle of urban design and land use known as "street hierarchy." Popularized in the U.S. in the 1960s, the idea was to segregate high-speed through traffic from residential areas by locating houses in a nest of meandering side streets while constructing fast throughways for nonlocal traffic. While this may sound rational, the effect is to increase the distance from residences to urban amenities, even when the houses and amenities are relatively closely located as the crow flies. The result: no one walks anywhere unless they absolutely have to.


Those who attended ECOS' last board meeting heard mayoral candidate Kevin Johnson say again that he sees Phoenix as a model of what Sacramento could become. To be fair, he wasn't citing Phoenix as a shining example of pedestrian-friendly planning. He seemed to be mostly enchanted with its successful downtown redevelopment. Still, when urban design so directly affects the transportation and lifestyle choices that a city's residents make, you have to why anyone would point to Phoenix as a successful model of anything!

Park(ing) Day

Looking for a little engaged interactive theater in your life? Check out two "PARKing day" events being organized in Sacramento. The idea is to (temporarily) convert parking spaces into, well, park spaces to illustrate the potential for increasing usable, green space in urban areas by reducing our reliance on automobiles and the space they demand.


Sous les pavés, la plage!

The Sacramento Valley: California's Great Exception?

The Sacramento River Watershed Program has released a fascinating online report on suburban sprawl and the demise of agriculture in the Sacramento Valley. It appears to be a work in progress, and the "best management practices" identified for governments to cope with sprawl are nothing new. But there is plenty of interesting information and analysis packed into the presentation. The GIS layer maps that accompany the text are especially noteworthy.

One of the more interesting observations related to the suburbanization and exurbanization of the Sacramento Valley concerns the availability of water. In most of the state, the availability of water is one of the principal checks on unrestrained sprawl. Not so in the Sacramento Valley, according to the authors:

Below the Delta and the federal and state pumping plants, water is the principal limiting factor for exurban sprawl. This is not the case for the Sacramento Valley and much of the Sierra foothills in the Sacramento Watershed. The groundwater basin in the Sacramento Valley recharges readily from the normally abundant rainfall in Northern California. In only a few areas has groundwater depletion become problematic, like in eastern Sacramento County where urban and medium density suburbs were allowed to develop solely reliant on groundwater pumping. Very likely, all the areas zoned for low density rural residential development have sufficient groundwater supplies.

Abundant groundwater resources are the exception in California, where most development has depended on guarantees of imported water. Thus, when making predictions about the build-out of the Sacramento Watershed, it is not prudent to look at the patterns from Southern California where local water supplies were the limiting factor, or the Bay Area, where confined geography have restricted exurban rural residential growth. Other areas of the nation may provide more accurate models for the potential of exurban build-out in the Sacramento Watershed.

Groundwater-fed development will also differ from development in regions that rely on surface water (including state or federal project water) in another important aspect. While surface water diversions are highly regulated and governed by a complex system of water rights and contractual obligations, comprehensive regulation of groundwater use in California is much less developed. Where the state plays an active role in overseeing the use of the state's rivers, streams, and reservoirs, the regulation of groundwater extraction is mostly a local matter. The jurisdictions charged with regulating groundwater uses are also those most directly embroiled in local disputes about land use and development. The state has little direct power to ensure the sustainable use of groundwater resources.

Healthy Spaces

Here, courtesy of MSNBC, is another testament to the intimate link between good urban planning and public health... and another reason to leave your car at home if you can:

A new study found that the year your neighborhood was built may be just as important as diet and exercise for shedding pounds. Those who live in neighborhoods built before 1950 are trimmer than their counterparts who reside in more modern communities, the study reported.

“The older neighborhoods had a reduced level of obesity because they were generally built with the pedestrian in mind and not cars,” said Ken Smith, a co-author of the study and professor in the department of family and consumer studies at the University of Utah. “This means they have trees, sidewalks and offer a pleasant environment in which to walk.”