The numbers aren't as positive as first believed, but financial prospects for the Black Rock reservoir proposed near Sunnyside are still optimistic.
That's according to the Yakima Basin Storage Alliance (YBSA), which commissioned two studies on Black Rock's potential economic benefits.
Initial estimates released earlier this month had Black Rock generating $5.8 billion in its first 20 years in recreation and residential benefits, as well as energy sales.
Mitchell Nelson, a Portland-based consulting group, carried out the research and presented the figures last Monday in Yakima.
On Friday of last week, John Nelson, a principal of the firm, revised the figures to show $3.8 billion in benefits from Black Rock, which would cost about $4.2 billion to construct.
"This is an unfortunate error," Nelson said Friday in a press release. "We apologize for the fact that attention will be deflected away from the positive values associated with the project, which are impressive."
The primary culprit for the numbers problem is that Mitchell Nelson had based its figures for energy sales based on the Bureau of Reclamation's 100-year table of estimates and applied them to a 20-year span.
In the same press release, Nelson said it was an error in judgment for his firm to consider energy sales since it was outside the scope of the original research. Nelson also suggested that the Bureau's figures for energy sales are conservative and should be looked at closer.
In a prepared statement, YBSA noted, "It is very important that this error not obscure the recreation findings; that the benefits for development if done correctly are much larger than the original estimate."
Chuck Klarich, YBSA's secretary, said Black Rock would still more than pay for itself, even with the reduced numbers projected on Friday.
"It still will generate almost $4 billion in benefits and the study doesn't include Black Rock's benefits to agriculture and fish," Klarich advised.