Cargo bike. I thought a bout a long tail like
this but like you said, hauling water with that would be a hassle. Something like the
bullitt would work but I'm leery of putting large loads like that in the front. There's also the problem of our road, its almost a 4x4 trail. Anything with a long profile is gonna have a bad time. Also any trike is going to be incredibly unstable on our road. If I lived on a nice paved road I'd go for the trike, even if they drive like a Semi!
Anyway, I have pretty much settled on a
Truck style bike something akin to the old Schwinn Cycle-truck, with a trailer for water.
As for grade and terrain, there's only one big hill (a mile long with about 15% grade) and lots of little hills (a hundred feet at most with 10% at most.) On top of that there's about a mile of unpaved road, .8 miles of that is almost 4x4 track.
MB rules here are pretty well defined by a proposed bit of
legislature. No ones really sure if it was enacted or not. I've spoken with a number of police officers about it and they have told me that pretty much as long as I'm not interfering with traffic and following at a minimum Bike laws I'm in the clear.
It boils down to this, as long as the motorized device does not exceed 25 MPH (for ebikes the Federal limit is 750watts) it is legal to drive. With the mid drive I propose to get I can regulate its speed with the controller. Though I seriously doubt I will be doing anywhere near 25mph with a load. I'm a little paranoid.
Now as for climate... I live in Puna, it's wet pretty much all the time. I am going to get high temp silicone sealant and make the thing as water proof as I possibly can. I too am concerned about it getting wet, that's the only reason I have avoided getting an electric thus far.
Distance wise, the dump is the farthest thing away. About 15 miles round trip, but trash bags aren't exactly heavy. The water is the thing I really worry about. The water station is about 8 miles round trip and I'd probably only take one of our 5 gallons but water is damned heavy.
And batteries... {sigh} I'm thinking I have to go with something lithium I just don't see myself getting the range or load capacity that I'm looking for with out it. On the upside if I take my charger with me the Rooster and I can hang out at the park after getting water while I give the bike a power boost.