I used to work for the U.S Army Corps of Engineers at flood control and water quality control projects; not as a hydraulic engineer tho. I think some rip rap(large stones/rocks) or rip rap baskets(same contained in heavy wire baskets/cages) could aid in preventing erosion to the dam. Grassland waterways(ditches with sod) can be used to divert water to the best entry location(s). can you get assistance in planning from your Dept. of agriculture? That is who we would use here in the U.S., sometime they even provide financial assistance or co pay. Probably wont be able to do much earth work in the wet season tho. The rip rap can be done anytime.

Hello mrsxtro
Being a poor visualiser, I would love to able to use your link to see images of the dam. Probably I'm doing something daft :)

We also use the dam wall as the driveway; however, it's fairly level except where the outlet was lowered (long story). The portion of the wall between the road and the water grassed up well, probably helped by some variety of couch grass a la Tony. My mother was in charge in the early days and put a lot of effort into grassing the outlet, particularly the more sloping portion below the culvert, with Pangola. This had to be planted by slips and irrigated. I do recall on visits home from OS protecting bare sections with hessian and planting through it; also, keeping coarse hay down with old weldmesh. None of this ramble constitutes advice!

Bush roads which are owner maintained may have lots of "whoa boys" i.e. mini diversion banks across the road which stop the water gaining speed, direct it off to the side. Slow down the vehicles too, help preserve the road surface.

I wish I could see your pix.
Cheers
Rose

Your picture links don't work.

Many of our farmers build water ponds and plant the sides heavily with tall fescue. Dense tall fescue, left ungrazed (by electric fencing), seems to develop deep roots and protects their ponds during times of overflow and runoff.

Sorry about the photos. Don't know what happened there!
Here's a link to the whole project. Hope it helps for those trying to visualise what I am talking about.

http://www.flickr.com/photos/tetlaws/sets/1454825/

Thanks.
-mrsxtro

Thanks for those pix mrsxtro, how about an image or two of the damage? Sorry to be so demanding :)

Rose
It's raining heavy drops here in central Qld....yippee.