One of the fundamental rules of medicine is “physician, first do no harm.” The same should be true for government. Recent history reminds us how important it is to protect our most pristine natural resources, and the harm caused from our failure to do so in the past.

The proposal to build a low-power hydroelectric dam above Sunset Falls on the South Fork of the Skykomish River is a prime example of a project that would do far more harm to our environment — and community — than its intended benefits.

It’s really unclear why the Snohomish County Public Utility District (SnoPUD) recently revived the dam proposal, given that the previous five attempts were dropped for reasons ranging from the “infeasibility” of the Sunset Falls location for hydropower to the unacceptable adverse risks to migrating salmon.

SnoPUD should also remember the overwhelming public opposition to these previous proposals. The people of this county have been abundantly clear about the need for renewable power produced in a cost-effective way. However, hydropower does not legally qualify as “renewable” energy in Washington. That’s probably why every other public utility in our state is diversifying and investing in clean-energy sources that do qualify as renewable.

There is also a real question of costs versus benefits. SnoPUD estimates that the dam will cost ratepayers at least $150 million, but could only produce less than a paltry 1 percent of the PUD’s overall power needs. What’s worse, the potential power would be generated mostly in the spring, when power is needed least. That’s when the Northwest has so much extra power; wind farms are actually paid not to feed power into the grid.

Even the estimate of $150 million may be wishful thinking. A study conducted by the independent consulting firm Rocky Mountain Econometrics gives us further reason for pause. According to the report, after adding in the cost of financing, operations and maintenance, the proposed dam’s actual cost of power would be as much as $345 million.

Using SnoPUD data, the independent study found that the proposed Sunset Falls dam would be the second-most expensive project in the utility’s portfolio, while failing to provide reliable power capable of meeting the needs of ratepayers.

While the PUD was critical of this analysis, it offered no independent study of its own to justify the huge expenditure.

What’s hard to understand is why SnoPUD is not using the $150 million earmarked for the widely opposed Sunset Falls dam to make efficiency improvements to its Jackson Hydro Project. Those efficiency improvements would generate far more power than Sunset Falls ever could, are much more cost-effective, and do qualify as renewable energy in Washington.

While we don’t know what the long-term costs of the Sunset Falls proposal would be, we know it would harm Washington’s most beautiful scenery. The South Fork of the Skykomish is so unique it was designated the first State Scenic Waterway to protect it from hydropower development. The Sky remains one of only four State Scenic Rivers in Washington today.

Our investments in energy need to be economically sound and ecologically defensible; this proposal fails to meet that standard. Washington taxpayers are spending tens of millions of dollars to restore salmon habitat and water quality. Habitat preservation is the most important (and least expensive) step in the process, but SnoPUD’s dam proposal would destroy an enormous amount of salmon habitat, in addition to the risk of “unacceptable” and “irreversible” impacts to eight migrating species we’re spending millions to restore.

And the dam isn’t even the most damaging part of the proposal. The intake cavern and diversion tunnel are the biggest problems. The massive tunnel, about two freeway lanes wide and two stories tall, would be blasted through salmon habitat and run half a mile underground. Stretching from the dam site to the base of Sunset Falls, SnoPUD proposes to divert the river from its natural course to their turbines. The decreased water left in the river would undeniably pose a significant threat to out-migrating wild salmon and steelhead.

While there are other small hydroelectric projects that are worthy of consideration, the proposed dam above Sunset Falls is just too little bang for the buck, and ultimately does more harm than good. When it comes to energy generation, it is important that a project have minimal impact on residents, ratepayers, and the environment, while also being cost-effective. This proposal doesn’t meet either of these key goals.

Sen. Kirk Pearson represents the 39th Legislative District in the Washington state Senate and serves as chairman of the Senate Natural Resources and Parks Committee. Lora Cox and Andrea Matzke are SnoPUD ratepayers and property owners downstream of the proposed project site.