Salinas River – Historical Perspectives & Flood Events 2023
Salinas River Channel Maintenance Program
Salinas River flooding occurred in January and again in March 2023, damaging 20,000+ acres of farmliand and costing our farm economy hundreds of millions of dollars with extensive damage to our environment, all because the river channel is not properly maintained for flow capacity, levee stability, and vegetation management.
The Salinas River provides our Valley with a unique water source for both farm and urban uses. This river has been artificially modified with flow rates maintained by releases from the upstream reservoirs during dry months each year (generally May through October). This year-round water source provides ecological benefits for a number of constituents throughout our Valley, as well as sustaining our local communities.
One of the more unique aspects of this river is that most of the land is privately held. This has provided land owners with the ability to maintain the dikes and levees used to control the flow of the river through their properties. After the flood events of 1995 and 1998, maintenance of the river channel was done under the supervision of permitting agencies; this maintenance not only controlled the rate of flow of the river and its path, but also decreased the amount of invasive shrubs and sediment that find a home in the river channel.
The maintenance of the Salinas River channel was halted twenty-five years ago when the Central Coast Regional Water Quality Control Board denied the renew of their permit for the maintenance program, and instead ordered Monterey County Water Resources to prepare a costly Environmental Impact Report (EIR) on the river channel watershed. After over three years of delay, the Environmental Impact Report for the Salians River Stream Maintenance Program was certified by the Board of Supervisors in July 2014.
In early October 2014, MCWRA received approvals from all resource agencies to move forward with a demonstration project in the unconstrained channel area between Gonzales and Chualar. Approximately 11 miles of the secondary river channel received vegetation management and sediment ‘smoothing.’ The aim is to improve capacity flow of the overall channel should additional water flows occur. See images of this project here. This demonstration project would become a model for other reaches of the unconstrained channel; a new stream maintenance program was then developed to manage the river channel in all reaches from south of San Ardo to the Monterey Bay coast.
Permits for the 90 miles of river channel maintenance were secured in September 2017, just in time for a short period of stream maintenance in October and early November 2017. While limited work was performed in Fall 2017, year-round channel maintanance started in 2018 and throughout the successive years; permits are scheduled for renewal in 2025.
Monterey County Farm Bureau thanks the landowners and farm operators who have stepped forward to manage the river channel these past two years; it has been a challenge both financially and regulatorily to meet the requirements imposed by the regional, state and federal agencies that have oversight of these private lands that just happen to have a river running through them.
Resource Conservation District of Monterey County has produced a short video on thier Salinas River Arundo Control Program. Arundo is a non-native, invasive weed that has infested 1500 acres along the river, in the second worst infestation in California. The RCD continues with their program of Arundo removal , treatment, and control through grant funding.
Flooding potential enhanced by vegetation and sediment
How did we get to this point, where the streambed is so choked with vegetation and sediment that water velocity is at 10% the rate of fifteen years ago, and nearly 30,000 additional acre feet of water are consumed each year by this vegetation? Simple answer: twenty years ago two of the state and federal agencies that issue permits for streambed maintenance withheld their renewal of these permits. Landowners along the river had been performing streambed maintenance within the channel since the 1995 flood with the aid of these permits; without the renewal of these permits, all channel maintenance was halted and vegetation and sediment began building up quickly over a period of the inervening eight years (until the pilot program was approved).
We now have a streambed choked with sand and unwanted vegetation (much non-native), and landowners are prevented from maintaining and protecting their own land (yes, landowners here actually own the riverbed itself, unlike other rivers in California). Trash removal from the river channel cannot be accomplished without violating envirnmental restrictions for access and accidental removal of vegetation. What should have been a continuous operation performed each year by the landowners and farm operators has now become a river impeded by its own sediment and vegetation.
Circumstances are far different now for farmland that becomes flooded; due to food safety requirements; production cannot resume until extensive tests are completed to ensure that no pathogens remain in the soil or water supply. This will fallow farmland for considerable periods of time, meaning from 60 days to many months.
And it’s not just landowners along the river who will lose property (read: topsoil) if we have a flood. Municipalities of the Salinas Valley have facilities for waste water treatment, domestic water systems, and parks along the river that are in jeopardy of being washed away if a flood event does occur. If the river does breach its streambed in one area, water could travel miles downriver before it were to rejoin the main river flow due to its meandering nature. Streambed course alterations would be permanent and the loss of other infrastructure, such as bridges, is quite possible, similar to what we experienced in the 1995 flood and again in 2023.
Do we really want to wash our topsoil, reclamation pond water, and other infrastructure into the Monterey Bay National Marine Sanctuary due to a flood that can be avoided, simply if we maintain the streambed properly?
Farmers and ranchers are maintaining the streambed, at their own expense, for the greater good of our collective community. The Resource Conservation District of Monterey County received their permit for exotic vegetation removal (Arundo donax) the past five summers and have worked on removing exotic vegetation in the river channel reach between King City and Chualar.
Let’s all realize that we need to protect our natural resources as working environments, and maintaining our river channel will prevent washing our topsoil into the ocean, causing untold effects on aquatic life and water quality in our bay. We must balance our environmental needs in a more holistic manner.