Eric Thompson

There is a LOT of regulation on stocking carp, so that also means that public sources of breeding carp are hard to find and risky to use.  Most wildlife operations for carp will get a permit and then buy and stock only sterile fish (triploid) which are very expensive.

If you determine you can ignore regulations, just catching some in local ponds can work -- the wildlife dept even conveniently tells you ponds with known invasive carp.
If you have trouble, I can let you know some side waters of the Columbia river where grass carp can be found.

I would say definitely:
perennial ryegrass
orchardgrass
white clover

probaby:
birdsfoot trefoil
timothy grass

maybe:
chicory
fescue grass
alfalfa

If you find a good pasture mix, you can just pour and spread -- you will only need half as much seed if you have access to a no-till drill, but for just 5 acres you can spread 100-150# of seed whenever you think it needs a jolt in spring or fall.  
You can locally pick up someehtin like:
https://www.outsidepride.com/seed/pasture-seed/pasture-grasses/all-purpose-pasture-seed-mix.html

I've had people order beef from my site not knowing it's pickup and local delivery only.  I have just refunded the money for the mistake.  The seller would not offer a refund??

I manage my pastures to get a lot of summer hay and I rotate on the 4 highest fields on my river bottomland (but there isn't much green grass) while feeding about half a bale per full size cow per day.  I have the cows together with their babies from this year, and most of the yearlings are in a separate field with the same hay and thin grass.

In our wet area, most of the hay put up is overmatured so calves will gain some winter weight but cows will lose some.

We couldn't get nearly as many animals through without the winter hay - it would probably be one-third to make it through

I run both 100% Wagyu and Wagyu/Angus cross.  I would recommend holding wagyu longer, and 3 year is better than 2....but 2 years is still excellent!  Don't worry about getting to perfection - harvest the meat when the time is right.
For any grassfed beef, I would wait until June or so to butcher in our area, since the winter body is more in survival mode than storing up fat.

Eric

Black Locust grows pretty great in Washington.  I have some on a fenceline right by a ditch, and very high water table will kill them, but I think they need at least a foot above winter water table is all.  More successful plantings I have had in lower spots would be ash trees and red alder.  For very low (nearly flooded) I have gone for bald cypress and pin oak.  Black Walnut like a good tap root and probably need a couple feet above the water table.

Since I often have drainage ditches in lowland fields, I clean out ditches into piles of the spoils 5-6 feet high, and then plant trees into the sides at 1-2 ft height -- really helps in very low areas!

Right, don't expect a realtor to get it, but do give them keywords and house features for the listing.  Even in Winter the time is good to sell now, so get it on the market as soon as you can!
Your garden looks beautifully done and will be seen as a real positive for the right buyer.  I think there are more buyers interested in a mini-homestead too with people being locked down and feeling helpless for so long..

Agree with the lemon suggestion - can also used powdered citric acid the same way since many home preservers have a bag of this hanging around.

My experience with NRCS projects is that any permit is ALSO needed - they don't overrule anything with that.  In general, you must please EVERY commanding body, not just one.

90 cu meters is not much for a pond -- your should clarify if that is "per year" like most drainage and earthworks projects are regulated.  Then by year 5 you can have a nice little pond...

A closeup picture would help - from far away they look like rose hips..