The nascent energy storage sector is often described in terms of how fast it’s currently expanding — and its potential for explosive growth in the near future. But across San Diego County decades-old deployments such as ice storage are still in use just as cutting-edge technologies such as lithium-ion storage grab so many headlines. At the sprawling Mission City office complex in Mission Valley not far from Qualcomm Stadium, 29 ice thermal storage tanks help slash the energy costs for the owners of three office towers who retro-fitted the facility in 1999.

There was a blue heron a few yards away from the Big Bear Marina. Mallards played in the water near the marina’s office. “This is pretty sad looking,” said Scott Ruppel, 60, as he sat in front of the marina office on a recent weekday morning. A frequent lake visitor, Ruppel, a Barstow resident, talked about the grass and other plant life — some green, some not — growing on land once covered by a 3,000 acre lake. The lake is now more like 2,200 acres, meaning 800 acres are exposed, according to Mike Stephenson, general manager of the Big Bear Municipal Water District.

The rumbling started Monday morning deep under the Salton Sea. A rapid succession of small earthquakes — three measuring above magnitude 4.0 — began rupturing near Bombay Beach, continuing for more than 24 hours. Before the swarm started to fade, more than 200 earthquakes had been recorded. The temblors were not felt over a very large area, but they have garnered intense interest — and concern — among seismologists. It marked only the third time since earthquake sensors were installed there in 1932 that the area had seen such a swarm, and this one had more earthquakes than the events of 2001 and 2009.

There were high hopes going into water year 2016. To hear some forecasters and scientists tell it, El Niño was coming to save California. With a little luck and a lot of rain, the drought might finally recede in its fifth year — or at least loosen its grip on the state.The weather phenomenon did show up, fueling some storms in Northern California. But it fell far short of the lofty expectations. On Friday, water year 2016 ended with a whimper.