When Lenny Krayzelburg first arrived in the United States, he was a teenager with an imperfect command of English. Though already a serious swimmer — he was first spotted by coaches in his native Odessa at the age of 9 — he was, by his own estimation, “only average.” Los Angeles’s Westside JCC helped change that. Krayzelburg swam on the center’s team and worked at the JCC as a lifeguard. Since then, Krayzelburg has gone far, most notably to the Sydney and Athens Olympics, where he won a total of four gold medals. But the years were not as kind to the JCC that once served as the swimmer’s aquatic home. Wracked with budget problems, the center had been struggling to keep its doors open. But Krayzelburg has swum to the rescue. A donation of more than $100,000 has helped keep the JCC pool — and those who use it — afloat.