A casual read (read wrongly) of the cited thread initially implied to me when there was no wind coastal, then things would happen further inland.
www.seabreeze.com.au/forums/Windsurfing/New-South-Wales/Girls-Riding-Group-WindsurfKitesurf/

Had me thinking (as I live between Springwood and Richmond) - what are Penrtih Lakes like for sail-boarding?
They charge for using their body of water - but it is cheaper than driving to Narrabeen then paying for parking. Can also walk back to the car, then drive back to get the gear, yes?

Additionally, is it possible to sail between the M4 and the Victoria bridge, tacking one's way along the river? I once saw Blue Mts Grammar school take three small cats onto Wentworth Falls lake - the but the wind alternated between brisk and nil-wind.
I could get used to the idea of inconsistent wind speed - it is inconsistent wind direction that may disappoint.

Hey Wollemi
I live in Katoomba and go down to Botany Bay if I want a sail. or Narrabeen if it's a westerly. I thought about Wentworth lake but it's too narrow in a westerly and if the wind comes from the east or north the trees are shadowing too much. The only 'alternative' I have heard off is the lake near Wallerwang out west past Lithgow. The water quality is supposedly quite poor though since mining water gets into it too. And the winds up here are extremely gusty. Not fun at all. Usually now it's once a month BB. I make a day out off it and it's quite good fun. Am a newbie myself by the way. See you somewhere soon

If you look at penrith council web site for the lake there is a windsurfer featured .When i rang & asked the council they said that is for the proposed lakes that havnt been built yet.
They were supposed to have a beach & life guards etc.10 yrs ago.
When i tryed to have a go there the lake had lanes in for rowing & the other side was no entry because of weed . So i dont think you can windsurf there . The other lakes are no entry .because they are still just old mining pits & havent been upgraded to the propsed lakes .Bu I do hear adds on radio for new estate claiming proposed lakes as 1 of there selling points . I just wonder if they mention that the proposal has been canceled now . Thats what the council told me .They dont have the money to complete it .

Prospect Reservoir, is off limits, as it supplies drinking water to sydney, and when i enquired about it, they said, it was due to possible contamination. You wouldnt want to have a diesel spill i suppose in sydneys water supply. But it was after Sept. 11 when i enquired and i suppose everyone was on high alert after those terrorist attacks.
the main access to Prospect Reservoir, allows picnicing, and has quite a lot of open spaces for parks, but there are fences and signs preventing and warning people from accessing the water. Which is a shame.

KR