So, I figure I'd best go ahead and note a couple things:
@Lauder @Jangel13 Getting a ditch dug is simple enough. Getting a larger effort done, like using the water to create a moat or trying to expand the river, is still doable but will be more difficult to succeed at. Both of the proposals do have more specific problems, too:
In the case of building a moat, that means you'll have to dig the moat deep enough to actually keep it full of water in every season. This would be difficult. Should you succeed, though? Yeah, you'll have a moat, and that's a big boon.
In the case of creating a branching part of the river that flows toward Gearalti, you'll be working uphill, essentially. Gearalti is located in the hills, and rivers naturally move downhill. To put it bluntly, you'd need a lot of extra hands to get that done - extra hands two clans in the Rain Season can't provide - and it's probably something that'd take more than a single season. Again, it's
doable, but it's probably not the best of ideas. It WOULD make Clan Gearalti happy with you, but... Difficult, and you wouldn't be able to finish that until after the floods have done their dirty work.
Just remember that each turn is a 30 day period, meaning you've got less than 30 days and realistically very little manpower. You've got projects in mind that are dealing with digging deep ditches for
miles. Serheim's proposal is more feasible than Seoras' in the span of a single turn (your clan village is located pretty close to the river), but both of them will be tough in the short term. Both are good long-term goals, however.
EDIT: I hate to sound like a Negative Nancy as your GM. But, basically, I'm noting this because I have to apply modifiers to the dice rolls - including negative ones - and if you guys don't stop the floods, that = bad. Diverting the flow of water is one thing. Trying to complete a grander construction project while ALSO trying to attend to your crops in the span of 30 days is quite another.