While zoning variances seem easy to come by for most downtown condo projects looking for increased density or height, there is one request that remains sacred: building in the protected zone around Lady Bird Lake. Long-standing rules prohibit construction within 200 feet of the former Town Lake. This is a problem for CWS Capital Partners which is trying to build three 17-story apartment and condo towers with 715 units on the south bank of Lady Bird Lake between Congress Avenue and I-35. The project has requested a variance to build 50 feet closer to the lake than . . .