No progress, no prevention

By Ashley Loza
Kern Valley Sun

Photos by Grace Harrison and Ashley Loza / Kern valley Sun
Fay Ranch Rd. experiences flooding after a stretch of warm weather. Just days before, crews had worked to build dirt berms to alleviate the flooding (bottom). Similar issues are found at Sierra Way. Both roads experience flooding when snowmelt causes flows in the South Fork Kern River to increase.

Springtime snowmelt is bringing with it an all too familiar sight – flooded roads in the South Fork.

Last week, both Fay Ranch Rd. and Sierra Way were flooded by overflow as the weather warmed up and river flows increased. While crews attempted to alleviate some of the flow with dirt barriers, leakage overtook both roads the next day.

The flooding is an ongoing issue during high-water years that has prompted much conversation but limited action.

The affected areas lie within the Audubon Kern River Preserve, an area that protects the South Fork Kern River. The preserve is considered a Globally Important Bird Area, housing some of the largest breeding populations of state and federally endangered birds in California. It is also home to the largest contiguous Great Valley Cottonwood Riparian Forest remaining in California.

But Kern River Preserve Manager Reed Tollefson notes that while environmental regulations are a factor in the slow-moving effort to keep these roads clear of running water, they are only part of the full story.

Primarily, the two roads were built under a watershed and are affected accordingly.

“Rivers are powerful, and they are not easily tamed or controlled or ‘fixed,’” said Tollefson.

The flooding begins with the amount of sediment carried down to the area from the river’s headwaters in the Sierra Nevada Mountain Range. Over time, Tollefson says that the river meanders from one side of the valley to the other.

Some years ago, flooding changed the course of the river to flow just south of the bridge at Sierra Way. Kern County took the lead in alleviating the flooding that followed, and with the Audubon’s concurrence, built a modest berm to redirect river flows back to the north.

Water begins running over Sierra Way as South Fork flows increase. Photo by Grace Harrison.

Then came 2017’s heavy precipitation, and the berm was washed away. Tollefson says that while the county also evaluated sediment removal from Fay Ranch Rd. to below Sierra Way, the work was never completed.

“I think [it was] due to both financial and regulatory issues,” said Tollefson, “as well as an understanding that the effectiveness would likely be overwhelmed by the natural transport and deposition of sediment in as little as one medium to large flood event.”

Part of the problem with sediment buildup, says Tollefson, is that Sierra Way is built on a berm across the river channel and secondary floodway, acting as a dam. This “dam” backs up the water, creating a “lake” full of slack water that sediment cannot move through.

On the opposite side of the road, higher water from Isabella Lake creates a similar issue.

Tollefson suggests that a modification of the road to allow more water to pass underneath could alleviate the flooding. In fact, the suggestion to build a better bridge at Sierra Way was made by former District 1 County Supervisor Jon McQuiston in the past.

“Kern River Preserve supported this proposal because we felt it showed foresight at understanding of this issue,” said Tollefson.

But years later, no progress has been made since the county came to help redirect the river and help with sediment removal.

“I think the county’s recent building up the berms are a helpful effort, but a long-term solution will take a more substantial effort,” said Tollefson.

“Sierra Way Road was designed and built at the same time as the dam, and time has taken a toll.”

Kern County Public Works was unable to respond before press time but intended to follow up on the matter.

L F - April 30, 2019

It seems to me that a relatively inexpensive, short-term fix, that would help until a more permanent solution is agreed upon, would be to add culverts under the road, similar to the one between the bridge and Hwy 178.
As for a long-term fix: a viaduct on pylons across the entire floodplain seems the best idea to me. Then the river could change course at will in a more natural way. Only a few feet high would be necessary. It might still flood in highest-water situations, but should remain above water much better than the current road.

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