maryjane said:Our neighborhood lots slope enough so that our spring heavy rains make a river and a lake in my backyard before the water goes down. (Under our fence to our next door neighbors.) I am building a dry creek bed to divert the water as it comes from my up-slope neighbors. ... to the back alleyway.
Great project! And congratulations to you for not cutting a trench right to the next-door-neighbor's fence. They would flood THEIR backyard instead of yours!
Hopefully the back alleyway will
continue downhill so the water can find a stream or river to carry it away.
The hardest part is often finding a lowER spot to move the water to! But it sounds like you have two directions that are lower than you are.
Of course I have no idea about your slopes, but sometimes a trench or dry creek bed can be combined with berms to divert water. If the sub-soil you dig out can be thrown a short distance to make a raised berm, you might be able to get away with a shallower trench and move the soil a shorter distance.
Another use for excavated subsoil is to raise the flooding parts of your yard a few inches. Turn them into RAISED beds which will also deflect some flood water.
However, it might increase the work a lot if you have to pull your beds' topsoil aside, move subsoil into the bottom of the bed, then move the topsoil back on top.
If you succeed in lowering the year-round water table, you'll also deepen your root zone throughout the whole yard. With a deeper root zone, plants should be more drought-resistant since they can find water deeper.
(Letting air get deeper into the soil makes the root zone deeper and stops roots from rotting and dying in every flood, then trying to grow back when the waters recede.)
