Keeping the Beaches From Slipping Through Our Fingers

In the natural process, wind, water and ice erode mountains to boulders, boulders to pebbles and pebbles to sand. Rivers carry the sand to the beach, and ocean currents and waves transport it southward along the coast.

But the natural process has gradually been thwarted. River valleys are dammed and developed, leaving beaches bare and resulting in recurring storm damage to coastal and flood-plain property.

Our solutions thus far have been to build protective barriers and to use tax dollars to allow owners to rebuild. But these solutions often create new problems and are very expensive, economically and environmentally. It’s time to look at more radical answers before we lose our beaches altogether. The problem starts inland.

When a dam is built, sand is trapped upstream, gradually filling in the reservoir. Downstream, floods--now controlled--no longer scour the valleys of their sediment, and no longer leave a new layer of topsoil in their wake.

When a harbor is built, sand collects on the northern jetties, depriving beaches to the south. South of the harbor and of dammed rivers, the coast is gradually laid bare by the unceasing action of the longshore current, which no longer deposits sand but only removes it from the beach.

As the beach disappears, we lose not only a recreation spot, but a natural protective barrier for structures. To compensate, truly pathetic barriers to the forces of nature, such as sandbags and seawalls, are used. In heavy storms, most of these barriers fail, and severe damage is the result.

Despite having been forewarned of such dangers, the owners of storm-damaged property apply for--and receive--hundreds of millions of dollars in state and federal disaster relief. We--you and I--pay not to relocate these people, but to allow them to rebuild.

Five or 10 or 20 years hence, the cycle repeats--and worsens, as more coast disappears and more dwellings are erected and threatened. There have been four federal disaster declarations in San Diego County in the past 10 years.

We subsidize these people’s life styles not only through emergency relief, but also by building more jetties, groins and seawalls; transporting and shuffling sand about; and untold other administrative and political costs. Nationwide, the tab has run into the billions of dollars.

There is a solution--at least for river valleys that are not heavily developed yet--and it, like the problem, starts inland.

First of all, no more buildings or roads should be permitted in the 100-year flood plain (the area flooded in a storm of a magnitude that occurs an average of once every 100 years). Owners of already developed property would be given the option of moving at government expense, but would no longer be eligible for disaster relief funds. This first step alone would make flood-control projects obsolete, thereby erasing the tremendous initial and sustained costs of building and maintaining such structures, and avoid the repeated cost of funding flood “disaster” victims.

Within the smaller limits of the 10-year flood plain, a riparian woodland preserve would be created. This would preclude the eventual necessity of funding expensive endangered-species recovery programs by preserving their threatened habitat, and would protect the main river channel from excess erosion by using the natural bank-stabilization characteristics of willows and other riparian plant species.

The wild river would also provide a greenbelt and public recreation area. The remainder of the plain (that land between the 10- and 100-year marks) would be designated as agricultural land to utilize the rich soil now periodically rejuvenated by river-bottom soil during floods.

It has been done before--in 1975, residents of Soldier’s Grove, Wis., asked to be relocated out of the river bottom instead of being regularly bailed out after severe floods. Since this one-time expenditure, no additional public money has been spent.

The next step in the solution would be to allow flooding of the now-cleared valley. That would not preclude the vital storage of water in reservoirs, but would perform several vital functions that we are currently forced to inadequately and expensively approximate. The floods would clear the valley of mature growth, which is important to the riparian ecosystem, and, as they receded, nutrient-rich topsoil would be deposited.

Finally, if not restrained, flood waters would transport huge amounts of sand from the mountains to the beach.

The third part of the solution is to build a dam bypass system to pump out sediment that now collects behind the dam and allow it to be carried to the beach.

It is conservatively estimated that a beach 100 yards wide and 105 miles long is waylaid behind the dams of the upper San Gabriel River alone! Most reservoirs become full within 50 to 100 years. Moving the sand out would not only restore beaches and thus limit storm damage, but would also increase the life of dams.

The other main contributor to the depletion of coastal buffering beaches is the interruption of the north-to-south longshore current, which transports sand along the coast.

Jetties at harbor mouths act much like dams; the flow of the “river” (the longshore current) is obstructed, and the sand collects behind the “dam” (the northern jetty). Not only does this deplete beaches farther south, but the accumulating sand clogs harbor entrances, requiring expensive dredging to keep ports open. (The City of Oceanside spends $2.5 million every other year for this.)

Despite contributing to the southward transport of sand, such massive periodic dredging operations serve only to maintain ports, and are not consistent with sustaining maximumly efficient buffering beaches farther south.

What is needed then is a continuous “sand bypass system” similar to that which the U.S. Army Corps of Engineers and the City of Oceanside are working on. Like the dam bypass system, this would approximate the actions of the natural sediment transport mechanism, and deliver the same benefits downstream as would the unaltered process.

The last step would be to relocate coastal residents and cease disaster relief to coastal areas. With state and federal aid, coastal residents and businesses would be offered either relocation assistance or one-time disaster relief. With the implementation of the previous four steps, the necessity for relief should decrease. But those coastal residents who choose not to move would be told that they live in marginal areas truly “at their own risk.”

These steps would negate the necessity for and astronomical cost of flood-control and coastal protection projects; increase the life of dams; restore river-valleys’ beauty and value as a greenbelt recreation area and agricultural zone; improve water quality; save millions of dollars in costs required to protect endangered species by coincidentally preserving threatened riparian habitat; reduce erosion and facilitate topsoil deposition, and restore beaches to their full buffer-providing width.

Best of all, these steps would permanently solve the problems they address, and at a fraction of the infinite cost of periodically and indefinitely funding sympdomatic catastrophic relief.