The blue and the green: DWP's plan should fund stormwater capture
The Los Angeles Department of Water and Power (DWP) just released its long term strategic plan for how the City of L.A. will meet its future water and energy needs. At a time when the City's historic water supplies are very much at risk it's clear that the distant sources we've relied on for many years are both diminishing and becoming much more expensive.
The new plan heads in the right direction. It states that it's a priority to develop new, local supplies, and that includes capturing the rain that falls on our region for free. But unfortunately the proposed long term budget doesn't give evidence of the agency's commitment to changing the course.
The role of a strategic plan is to set a strategy and to provide a basis for leadership and direction. Because of the imported water supply threat, it's time to make a turn and invest the agency's resources in developing local supplies and the economy. That's what this plan should do. But unfortunately because the budget doesn't follow through, it sends a confusing message to DWP's staff, L.A. residents, and innovators who want to help.
The plan's local stormwater source is only one centralized stormwater to groundwater-spreading project in Tujunga, that when finished will total only about 20,000 acre feet a year. This is only a drop in the bucket compared with what's possible. It's roughly the amount of water yielded by one inch of rain on the city of Los Angeles, where the annual rainfall total averages about 15 inches. But to capture a large part of this water, DWP will have to shift to a distributed system that captures water on public and private property using a combination of cisterns, mini-infiltration basins, bio-swales, and mulch.
DWP has not yet seriously evaluated such an approach... until now. In the coming year they will conduct a study - a stormwater master plan - to calculate the potential for a distributed stormwater system to meet a significant portion of the city's total needs.
TreePeople is currently working on the stormwater master plan with DWP and are eagerly awaiting the results.
DWP's plan and budget are the vehicles by which it should declare its leadership and send a message that it is heading in the direction of developing a significant amount of local supplies through stormwater capture. And it should follow with a financial commitment that demonstrates it. Here's a graph that conveys some of the urgency: