We need are liable source of water in a state with less than reliable precipitation. We need to store it when we get it, and conserve it when we don’t. Of the three main storage methods California depends on for a clean and reliable supply, innovations in groundwater storage show the most potential. In the Pajaro Valley of Central California, water managers and stakeholders are testing a novel approach to incentivize groundwater recharge, that uses sophisticated monitoring and a financial incentive based on water bill rebates.
They call it recharge net metering. A recharge net metering basin or other structure built on private land captures excess storm runoff during high flow events. It slows the water down and lets it infiltrate back into the ground. The basin is instrumented and measures how much water soaks in. Farmers and landowners in the Pajaro Valley pay to pump groundwater. The amount their recharge basin can infiltrate essentially runs the meter backwards, and the water district gives them a rebate on their water bill. The more water that infiltrates, the more financial benefits they get. Scientists at UC Santa Cruz have led the research and development on the technical aspect.
They’re working in partnership on regulation, implementation and outreach with the Pajaro Valley water district, the Resource ConservationDistrict of Santa Cruz County and forward thinking farmers and landowners in the Pajaro Valley. – In the Pajaro Valley, we are heavily reliant on groundwater as our resource. About 95% of all the water used here each and every year is pumped out of the ground. About 28,000 irrigate dacres brings to production between 900 million and a billion dollars worth of produce each year. – The RCD and UC Santa Cruz act as third party certifiers for the recharge net metering program. We’re the ones that are responsible for identifying project sites, and then monitoring the sites to quantify the amount of water that’s going in the ground. And based on our findings, Pajaro Valley Water Management Agency issues a rebate to the landowner. – So we found that even during drought periods, there are frequently very intense, relatively short storms that generate a lot of runoff. So for example, wayback in water year 2015, most of the rain that year fell during one week, and most of the rain that week fell in one afternoon, and this system actually achieved its full annual goal in that one week.
And most of that runoff occurred in one afternoon. If we hadn’t had the system here, much of that water would have ended up flowing off into the Pajaro River and out into the ocean at a time when that river was already at flood. – Our company has been farming in this area for close to 100 years in the Pajaro Valley. As farmers in the Pajaro Valley, we have a common goal with the local water managers to try to do whatever we can to augment recharge and so that we’re making this basin more sustainable. – If we can be well positioned to capture rainfall runoff when it comes even in the middle of a drought, especially in the middle of a drought, and help to infiltrate that water into the groundwater basin, we will be more resilient in the future. (soft instrumental music) (whooshing)