THE 252 HOUR PRIVATE PILOT WAS ATTEMPTING TO LAND HIS SKI EQUIPPED PIPER J-5 AIRPLANE ON A FROZEN LAKE WHEN THE LEFT MAIN GEAR COLLAPSED, CAUSING SUBSTANTIAL DAMAGE TO THE LEFT WING LIFT STRUTS. HE SAID THAT THE LEFT MAIN GEAR ENCOUNTERED A SNOW BERM THAT WAS LARGER THAN ANTICIPATED AND THAT THE GEAR WAS OVERLOADED BY THE IMPACT. THE PILOT RECOMMENDS A CLOSER INSPECTION OF GROUND CONDITIONS PRIOR TO LANDING, AND NOT LANDING WHEN SNOW DRIFTS ARE VISIBLE FROM 100' AGL.