It would be difficult to overstate the importance of jetties to the navigability of the lower Columbia and the economy of the Pacific Northwest. The $30 million in repairs to the north and south jetties in the past four years is money well spent.

Without the jetties, the mouth of the Columbia would be only 20 feet deep and impassable for all or most modern ocean-going ships.

Only a century ago, sailors were sometimes trapped inside or outside the river estuary for weeks at a time while waiting for rough bar conditions to abate. It was the jetties, coupled with routine maintenance dredging, that turned the Columbia from a horror story that mariners shuddered over into the relatively straightforward transportation corridor it is today.

Jetties at the mouths of tidal rivers perform several related functions. They serve as a gigantic hose nozzle, helping the river itself scour out its channel. They concentrate a river’s outflow into one definite channel that can be more easily maintained. They protect that channel from littoral drift, the sands that flow along the beach carried by the tides and waves.

Like most human interventions in natural systems, it can be argued jetties are not an unalloyed good.

The Columbia’s ocean jetties, coupled with disposing of dredge spoils in deep ocean waters, have contributed to severe shoaling in Baker Bay south of Ilwaco, while leading to beach erosion from Cape Disappointment north at least to Washington’s Washaway Beach. On balance, however, there is no serious question that the jetties do us far more good than harm.

Before the expensive repairs that formally concluded earlier this month, there was a real and growing risk that a single intense winter storm might breach one or both jetties. It’s likely this would have quickly released a torrent of sand and sediment flooding from behind the breached jetty into the navigation channel, paralyzing as much as $14 billion annually in shipping and crippling an array of Columbia-dependent industries, from wheat farmers to car dealers. Even local fishermen rely on the safe passage assured by the jetties.

Congress, the U.S. Army Corps of Engineers and jetty repair contractors Tapani Underground, Inc. of Battle Ground, Wash., and Kiewit Pacific of Vancouver, Wash., all deserve thanks and praise for their work on this issue. Repairs were made as professionally as one could wish.

The next steps are more difficult. These were repairs. What is needed is a complete overhaul of both jetties at a cost currently estimated at up to $200 million. If anything, this might represent a miserly budget for such work. After all, the jetties were first built in an era when costs were a small fraction of what they are today, when worker safety was a secondary consideration, and when environmental and endangered species protections were nonexistent.

We’ve celebrated jetty repairs long enough. Now, without delay, we must begin the arduous process of obtaining congressional funding to study and model the jetty rehabilitation project, which is in its beginning stages.

Looking ahead to a period when the sea level is rising and storm intensities growing, there’s no time to lose in preparing these vital structures to survive another century.