In passing the 1978 law that detached District employes from federal civil service legislation, the D.C. City Council adopted a method for giving its 13 members and the mayor automatic and periodic -- usually annual -- pay raises without anybody having to take political static.

Under that law, Mayor Marion Barry has just quietly received a $2,750-a-year pay increase and the 13 members of the council have received increases of $1,605 each. It's no secret, but not a matter proclaimed, other than a quiet notice on Page 6084 of the weekly D.C. Register.

The law provides that salaries be adjusted to within 0.1 percent of the annual rise in the regional consumer price index, but they cannnot exceed the average increase approved for top-ranked D.C. administrative officials who have "career service" status.

While the local consumer price index rose 4.9 percent in the 12 months covered by the required survey, career service employes were granted only a 3.5 percent pay rise. So, according to the D.C. Office of Personnel, that's what the mayor and council members also get.

Barry got, as of Oct. 13, an increase to $81,380 a year from his previous $78,630; City Council Chairman David A. Clarke, who is the only council member paid for full-time work, got a raise to $57,475 from the previous $55,870, and the other 12 council members got increases to $47,475 from the former $45,870. To put this into context, members of Congress earn $75,100.

A postscript: The D.C. government persists in making the dollar amounts of the pay increases of the mayor and council members look like a mystery. The annual notice, published in the D.C. Register's Oct. 25 edition, contains the amounts of the newly authorized salaries but no comparison with the previous ones.