Subject to the limits hereinafter set forth, a mutual savings bank may expend its funds for the improvement for public use of privately owned land as parks or recreation areas, including but not limited to "vest pocket" parks, provided that the owner of such land will:
(1) Permit public use thereof for a period of at least eighteen months or for such longer period and subject to such other requirements as the bank may impose; and
(2) At or before the end of public use, permit the removal of all such improvements which in the bank's judgment reasonably may be accomplished.
As used in this section, "public use" means use without regard to race, creed, sex, color, or national origin. The amount expended hereunder and under RCW
32.12.070(2)(d) in any calendar year shall not exceed one-half of one percent of the net earnings of bank for the preceding year.