reporter: tempering that jo-- this is the first major project christo has completed without his wife, jeanne claude, who died in 2009. photographer wolfgang volz says she is missed. >> if we have a big problem we always say: ¡what would jeanne claude have done to fix it, if it were catastrophe or something like that? ( laughs ) you deal with permanent danger of catastrophe. >> reporter: while there haven't been any "catastrophes," the floating piers have posed some unexpected challenges. rain and wind force parts of the piers to close at times. monitors like this woman, instructed to keep baby strollers off the outer pier, because of the wind, face arguments from upset moms. wear and tear from the much- larger-than-expected crowds also cause the piers to occasionally close at night for maintenance and repairs. but, all in all, as christo passed by on his boat, visitors have cheered the floating piers as a success. and christo isow looking ahead to two more large scale projects- a pyramid-like structure in the united arab emirates and a curtain of fabric over the arkansas river in the u.s., which ha