We do _not_ recommend this entire stretch be considered a whitewater run. Rather, it has a couple of areas with _potential_ for PnP (park-and-play).
That said, numerous listings on AW (not only in the upper Midwest, but also in various other parts of the country) contain miles-and-miles of flatwater, with a few random bits of whitewater. Thus, inclusion of this reach seems in no way out of line!
Flow information
At the Kekoskee Dam, drainage area of the E.Br.Rock River is 183 square miles (per USGS Stream Stats software). There is a gauge on the S.Br.Rock River at Waupun, where drainage area is 63.6 square miles. Thus, flow here _could on average be_ on the order of 2.877 (about 2 and 5/6ths) times flows shown on that gauge. The 'virtual gauge' being used here reflects that calculation. However, expect this calculation/approximation to be misleading (wrong) a lot of the time. The virtual gauge is merely an indicator of times when flows _might_ be adequate to make it _worth checking_ this location for possible play.
NOTE: There is also a gauge on the (main) Rock River (where drainage area is 456 square miles, thus, flow here _could on average be_ on the order of 0.4 (4/10ths) of flows shown on that gauge). However, that gauge is listed as being '1700 ft. upstream of dam, at Horicon.' Since that dam is used to regulate pond height in Horicon Marsh, flows on that gauge will be more affected than the prior mentioned gauge.