Drought: Rain fell, but where did the water go?

Rain fell, but where did it go?  Photo Credit: Brandon Doran
Rain fell, but where did it go?
Photo Credit: Brandon Doran

The past week or so brought much needed rain to Northern California. But where did all that water go? Unfortunately, here in the Bay area most of it ran out to the Bay through the storm drain system, carrying trash and pollution with it.

There is a disconnect between how we manage water for flood control, quality, and supply. The goal of flood control systems is to remove water from our roads and urban areas as quickly as possible. Unfortunately, this water is carrying a significant amount of pollution with it, degrading water quality in local waterways and the Bay. We are also experiencing a drought, and yet we are allowing runoff from our city streets to flow through our storm drains and out to the Bay rather than putting that water to beneficial use.

Flooding

Before we urbanized the landscape of Northern California, rain water soaked into the ground where it fell, recharging groundwater. Now that the land is covered in impervious surfaces like asphalt and buildings, our cities have created a network of storm drains to carry water from our urban streets to nearby creeks that flow out to the Bay. However, flooding still occurs when trash, leaves and other debris clog storm drains, or when the local waterways become overwhelmed by the sudden and drastic increase in water flowing in from storm drains.

Pollution

Because of the risk of flooding, storm water policies have focused on removing water from city streets and urban areas as quickly as possible, which means water flows directly into the waterways without treatment. As a result, pollutants like heavy metals, oils, pet waste, and trash are carried by the storm water into our waterways. This is why Save The Bay has prioritized stopping trash pollution at the source, working with cities and counties throughout the Bay Area to ban plastic bags and Styrofoam. We have also turned our attention to cigarette butts which are commonly littered on streets and sidewalks near storm drains.

Beneficial Use

There are better ways to prevent our urban areas from flooding than sending all the water, and the pollutants picked up along the way, out to the Bay and ocean. We depend on the streams and rivers of the Sierra Nevada Mountains to deliver water to the entire state even though rain falls throughout the state. The state of California is facing both a drought and groundwater depletion; we should be thinking more comprehensively about water supply solutions.

As water simply soaks into soil, pollutants are filtered out. This clean water then soaks into our groundwater system, replenishing water that we remove through wells and pumps. Homes have gutter systems that remove rooftop water and direct it out of a single pipe. If this pipe drains onto an impervious surface like a sidewalk or driveway, the water will run into the storm drain. If the pipe drains onto dirt or grass, the water is soaked into the ground, replenishing groundwater. Better yet, this water can be captured in barrels to use for watering plants during dry days. On a larger scale, the same concepts can be used for larger buildings and structures, or larger pieces of land like city parks. Another option is to create more permeable space, including paving streets with porous asphalt, green roofs, and more open space like parks.

Luckily, California legislators and policy makers are currently working to address the many water related issues facing the state, and are taking a more comprehensive approach. For example, Senator Wolk’s water bond bill, SB 848, includes $500 million for storm water capture and reuse projects. These projects are essential to improving water quality and can increase water supply. We’ll have to wait and see what decision makers will agree upon to address the significant water issues facing the state, but one thing is for sure; doing nothing is no longer an option.