The Importance of the Greening of California

The majority of California lies within an ecological zone named the “California Floristic Province,” which is considered a Mediterranean ecosystem. Across the globe, Mediterranean ecosystems represent less than 3% of the land and are considered more threatened than rainforests. In California’s ecosystem, only 25% of original habitat currently remains, as the remainder has been altered by agricultural, industrial, and residential uses. Consequently, numerous endemic vegetative species have declined in population numbers.

Within the California Floristic Province, the Santa Susanna Mountains, San Gabriel Mountains, and the Santa Monica Mountains collaboratively form a watershed that fuels the Los Angeles River that extends through the entirety of Los Angeles. Once upon a time, the 850 miles of the Los Angeles watershed fed a meandering river lined with vegetation. Trees thrived, scrubland grew, and birds and wildlife flourished along the Los Angeles River’s 51 mile length. However, with the onset of settlers and population growth, the unpredictable river and its changing path and periodic flooding instigated its concrete channelization in the 1930’s by the marine corps. The wild river became a glorified storm drain and lost its identity. As for the river’s watershed, today over 60 percent of its expanse is paved in concrete.

Across the globe, urbanization leaves a concrete footstep, and often the effects not only marginalize wildlife habitat, but interrupt nature’s water cycle. Considering the Los Angeles area, the paving of its watershed produced impermeable surfaces that inhibit nature’s normal cycle of water percolation into underground aquifers. Throughout history, such aquifers provided freshwater for various civilian uses, including drinking water. Before urbanization of the Los Angeles watershed, 80% of rainwater percolated into the ground to recharge aquifers. Today, eight percent of rainfall seeps into the ground. Most the remaining stormwater flows over concrete before being funneled into the Los Angeles River and ultimately into the Pacific Ocean. Freshwater is lost.

On the cusp of a statewide water shortage, various Los Angeles politicians, scientists and visionaries are striving to address the issue. In particular, one component is the greening of the Los Angeles River, known as the Los Angeles River Revitalization Master Plan….

Brandon Perkins
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