What effect did last week's flooding rain waters have in the estuary? With regard to high water, not much. Water levels in the estuary are controlled by sea level; flooding due to runoff rarely occurs south of Catskill. The river did rise at Albany (Hudson River Mile 145) from 4/28 to 5/1, peaking on 4/30 about three feet above the levels a few days before and after. Fourteen miles downriver at Schodack Island this crest was only about a foot and a half above the levels of the preceding and following days. At Norrie Point (Hudson River Mile 85), no peak was apparent.While the runoff had little effect on water heights in the estuary, its impact on the salt front was another story. From 5/4 to 5/9 salinity was below detection limits at Piermont (Hudson River Mile 25), testing the ability of the Piermont marsh’s brackish water species – saltwater cordgrass, diamondback terrapins, and ribbed mussels, for example – to tolerate wide swings in salt concentrations. And off Castle Point in Hoboken, New Jersey (Hudson River Mile 3), average daily salinities were in the range of 3-5 practical salinity units during that period – very low levels little more than 4 miles from the Statue of Liberty.