One of the most compelling visions for Berkeley’s parks included in Louise Mozingo and Marcia McNally’s study, is the early 20th century proposal that parks be part of an integrated system of large and small open spaces linked together along the natural creek channels from the hills to the bay. Underlying this vision is the seemingly revolutionary idea that natural open space would be the primary infrastructure used to define the physical form of the built environment. A century ago as this city was being formed, an enlightened thinker imagined an urban structural system for this place with nature and the built environment deliberately and dynamically balanced. And it could occur throughout the city, with all citizens having equal access to open spaces.
Berkeley did not choose that vision. Instead, Berkeley embraced a more predictable urban development pattern that would obliterate most of its internal open space, rather than integrate it with the built environment. Thankfully, the ridgeline, the UC campus, and a few select park sites were preserved. And over the past few decades, we have been able to buy back some parcels to create parks in under-served neighborhoods, but rarely along creeks. As Louise and Marcia’s study shows, most of our neighborhoods now enjoy parks, but they are largely isolated and not part of an interconnected green infrastructure system needed to both serve and counterbalance the relatively dense urban development.
In my opinion, the primary emphasis and challenge for our park system over the next decades should be to create linkages among the parks and open spaces that will serve both recreational and environmental purposes. Berkeley could become a city within a park, not simply a city that has some nice parks within it.
The logical place for a system of green linkages would be along our creeks, as suggested in the turn of the century vision, and by many activists as well. But realistically, that is a near impossibility for Berkeley today. With some notable exceptions, most of our creeks have been filled-over, with buildings and other urban developments allowed above. Our few remaining creeks carry only a portion of the water draining through the city, providing important but limited ecological and spatial linkages, mostly through private properties. Most of the stormwater has been diverted into a constructed drainage system in the public street rights of way. Our creeks and storm drainage now function as separate parallel systems with very few interconnections
and a nearly incomprehensible division between public and private responsibilities. Past decisions have severely limited the option to make our creeks the centerpiece of our green infrastructure.
I think we should be focusing on our streets to create the system of green linkages and, in so doing, nurture a new form of urban ecology. The water is there, rather than in the creeks. The streets are in the public domain and subject to direct public actions. We are required to make significant capital investments along the streets to address polluted stormwater runoff and serious flooding problems—both issues that can be addressed effectively by green infrastructure. The combination of these factors has created a rare opportunity to reconceive our streets to provide broader public benefits than they do today. We can seize this moment to simultaneously address serious environmental problems, enhance the city’s urban design with green infrastructure, and integrate our open space network within the public domain. Some specific considerations.
Our streets are configured primarily for vehicles, with most accommodating pedestrians along the edges. They are generously sized in favor of vehicular traffic and parking. But of equal importance for the city’s infrastructure, streets are also designed as the central feature of our urban stormwater drainage system. Storm pipes, sized to carry small volumes of water from normal storms, lie below the streets with periodic drain inlets along the curbs. The street surfaces are designed to carry overflow floodwaters from the larger storms that can’t be contained within the pipes. Streets in combination with the subsurface pipes have, in essence, become our stream corridors. But as currently conceived, they serve only as flood conveyance without the ecological complexity, recharge potential, and aesthetic layering of streams. And they don’t work very well.
We could reconceive our streets to be a multi-layered urban stream system that happens to convey vehicles, rather than a vehicular system that happens to carry stormwater. Within this context, the streets could be retrofitted to slow the storm water, filter it, support vegetation, and provide flood protection like a stream, but in an urban context. The landscaped portions of the street would trace the actual urban drainage patterns and provide functional green connections through the city. In areas with sufficient width, the sidewalks and landscaped areas could support expanded recreational activities in addition to connecting parks and open spaces together.
The development of more complex, layered uses of the streets will challenge the spatial assumptions for the different uses. Vehicles could function just fine with less paving, for instance, especially when considering competing uses that might share the space. Narrowed and re-aligned driving lanes, re-structured parking areas, re-configured medians, and re-conceived pedestrian areas are just some of the ways in which additional space for retrofitting could be found. A new vocabulary of permeable materials and planting will be added to the public realm, a change from the impervious monoculture of our roads today. Changes like these will give our streets a more park-like character, making them feel like they are part of a larger open space system rather than simply roadways with sidewalks.
A look at our cross-town north/south connector streets, like Shattuck Avenue, Adeline Street, California Street, Sacramento Street, and San Pablo Avenue might be instructive. The large rights of way and central medians will give them important roles to play in a new system of green infrastructure like flood control, for instance, which is a serious problem in west Berkeley. The north/south connector streets run across the prevailing westerly running slope and could serve to cut-off the floodwater from above, detain it, and then release it gradually to lessen the impacts downstream. Under this scenario, the medians as well as parking strips are prime candidates for re-configuration in order to slow, filter, and detain water. One option might be to relocate all or part of the medians from the center to the sides of the road to capture the water away from traffic lanes while creating a more park-like condition for the pedestrian environment.
Selective east/west streets that run with the prevailing slope as well as some smaller north/south streets could also be re-worked along their edges with permeable paving and water gardens to slow the water down and filter it as it moves downstream. Parking along these streets could be clustered in counterpoint with the gardens, and the driving lanes realigned to slow traffic. These streets would become connectors to the various parks throughout the neighborhoods, linking the ecological functions as well as the people with the larger cross-town facilities.
These are not inexpensive changes. But we are faced with enormously expensive, mandated infrastructure costs for pollution and flood control that will affect the streets anyway. We should use these imperatives to our advantage and re-imagine our community as a city in a park.
John N. Roberts is a Berkeley resident.