This paddle is up the grose river from either Navua Reserve (GroseWold) or Yarramundi North Reserve. You can paddle upstream against the flow if the river is deep enough and have lunch or camp overnight on the sand banks near the last rapid. then paddle back down to Navua Reserve. If you are doing an overnight trip i would probably leave my vehicle along the road side outside Navua reserve at the gates get locked at sunset. Both Reserves are isolated and so cars left overnight might be vandalised. The walk from the car to the river is a little chorter at Vavua resere than on the Yarramundi side of the river.
The river is usually a shallow sandy bottom river and so you have to find your way in the deeper channels over the sand. But i have enoticed after the 2013 floods the river has been scoured out and there are a lot more pools between the sand banks, so i imaging at lower flows you will need to walk over these sand banks. The river is a great example of how Australia rivers where prior to european settlement with large logs locking in the river bed and as there are no livestock on the adjoining properties the banks have native vegetation comeing right down to the river. And it is so close to Sydney. There are issues with Lantana and Bell Minor birds causeing die back in the tall gum trees but this is being addresses by the Local Land Services in partnership with the National Parks and Wildlife Services (NPWS) and private landowners starting from the upstream end. There was some work done by NPWS and Sydney Bass fishing club about 4 years back it that areas is now just pristine bushland
We paddled up the river when it was between 0.9m and 0.8m and it tool about and 2 hours to paddle up the river to the last rapid and one hour to paddle back to Navua Reserve
 
In addition at times when the Nepean and Hawkesbury are in flood due to the rain in the upper catchment and the Metropolitan dams or Warragamba dam spilling the Grose river will start to bank up as the water slows down or flows out of the Hawkesbury River back up the Grose River. But you will not see the impact of this on the Burralow Gauge. However you can use the near by gauge at the North Richmond pumping station http://www.bom.gov.au/fwo/IDN60233/IDN60233.567098.plt.shtml as an indicator. The river at this gauge is tidal and fluctuates between minus 0.5 (low tide) and zero (high tide) and during the high tide you can usually paddle on the first few kilometres of the Grose River during low flows. So when the Hawkesbury is in flood I would expect a meter on the North Richmond Gauge would translate to a meter on the Lower Grose. I am not sure of the drop in altitude between the last rapid on the Grose and the junction but i would expect it to be no more than 2 meters. So if there is 2 meters on the North Richmond gauge you should be able to paddle about 5km up the Grose River from Yarramundi North reserve or Navua reserve.