In picking Block 79 as the site for the new $45 million Utah Jazz arena, the Salt Lake City Council - acting in its capacity as the city Redevelopment Agency - made the sensible and logical choice.

By whatever measure applied - cost, potential delays, number of private businesses affected, water table, desire of the Jazz ownership - the northern downtown site is best.That location, known as Site A, is bordered by South Temple, First South, Third West and Fourth West. The alternate location, Site B, lies between Third and Fourth South and West Temple and Second West.

It certainly could not have been easy for the RDA to overrule its own Planning Commission, which voted 6-1 earlier this week in favor of Site B. But the compelling arguments in favor of Site A are reflected in the RDA vote - a unanimous 7-0.

The City Council-RDA members are to be commended for their quick decision. Because of the hours of testimony at the hearing this week, it had been thought that a decision might not be made until April 11 at the earliest.

Every move to expedite the new arena is another plus. Plans call for the arena to be completed by Aug. 31, 1991, only 30 days before the start of the National Basketball Association season that year. That doesn't allow a lot of time for delays.

The arena itself will be built by Jazz owner Larry H. Miller, who will raise the necessary $45 million. The property on which the arena will stand is to be acquired by the RDA through a $20 million bond program.

The choice of Site A certainly simplifies the property acquisition. Only four businesses and two major landowners occupy the 10-acre block. Relocation costs reportedly will be zero and demolition costs only $190,000.

By contrast, Site B has more than a dozen businesses. Relocation costs would have been $275,000 and demolition $320,000. In addition, the business owners had threatened court action to stall condemnation of their property.

The RDA choice also follows the recommendation of the arena architect and a Regional/Urban Design Assistance Team. The R/UDAT group, composed of out-of-state consultants who studied the city last year, said the northern site was best for an arena because it tied into an "entertainment, arts and sports district" already anchored in the area by the Salt Palace.

Now that the site decision has been made, all parties need to push ahead with the new Jazz arena and guarantee that major league professional basketball will remain part of Utah.