Deposits at commercial banks in the Washington metropolitan area rose about 11.31 percent in the past 12 months to a record $14.981 billion on June 30, compared with $13.459 billion recorded a year earlier, according to a Washington Post survey.

The 11.31 percent increase is consistent with annual growth rates established over the past several years and indicates no special increase in banking activity during the past year.

All three jurisdictions surveyed -- Washington, Maryland and Virginia -- showed increases in total net deposits, although a dozen local banks registered decreases in total time and demand deposits from June 30, 1980.

District banks and their branches once again posted the largest annual increase, showing a 15.09 percent jump in savings, up from total net deposits of $6.473 billion in June 1980 to just over $7.45 billion a month ago. During the quarter ended June 30, 1981, District deposits showed an increase of 5.72 percent, or $403.3 million, from $7.046 billion on March 31, 1981.

Maryland banks and their branches showed more moderate growth, increasing 8.15 percent to $3.956 billion in June, compared with $3.658 billion a year earlier. Maryland deposits grew 2.67 percent during the quarter ended June 30, up more than $102.8 million from the $3.853 billion in deposits recorded on March 31.

In Virginia, deposits at area banks rose to more than $3.574 billion, up 7.64 percent over last year's figure of $3.320 billion.