Sell it and buy something on higher ground. I say this as someone who lived in a home up on piers in CT. A friend let me live in her summer home for a couple years (year round) after my home had been destroyed by a different type of flood that my insurance wouldn't pay for (long story).
Anyway, it was an absolutely beautiful place to live when no flood. While living there I spent hundreds of hours and thousands of dollars rebuilding walls and dug down way below grade to the water table during the dry season to put in additional reinforced concrete piers which I set thick steel plates in to bolt the floor joists and sill plates of the house solidly to the piers. Created swinging spring loaded doors to let the flood water into and back out of the "basement" area which was a concrete slab on ground level with walls I built with pressure treated wood after the previous walls went downriver during an earlier flood. Previous walls had no chance with just air behind the walls other than what water leaked in until the pressure blew the walls in.
It flooded both spring seasons while I lived there although it hadn't flooded for a few years prior. The first flood we (the residents) were told the flood gates for the dam would probably need to be opened the following day (they were) and to evacuate. So ya that sucked and clean up and repairs after flooding took a lot of time.
The next spring there was a lot of snow that winter in Northern New England and a quick warm up with heavy rains in the spring. I knew there was a high possibility of flooding so I parked up on Rt.34 the main road and walked in to the house. About 8PM the firemen came and said the dam operators wouldn't be opening the flood gates until possibly the following day so no need to evacuate and I could spend the night there.
About 3AM the firemen were beating franticly nonstop on the door. Once awakened, groggy me came down the stairs to a couple firemen in waders with flashlights who told me I needed to evacuate. I said "OK I'll gather up some clothes and my laptop and go, I left my truck up on 34". Their reply was "NO, RIGHT NOW! Get your keys and come with us, you can't walk." It was pitch black, no power in the house, raining heavily. So they shined their light inside and I grabbed my keys and coat and locked the door. Fireman says "Hold my hand tight ! " As we start down the deck stairs my feet get wet. I then realize everything around the house is river, the water is waist deep in the yard already and although the air temp was above freezing it was really, really, cold water moving swiftly. They'd driven in with a big monster truck tall enough to just barely be above the water which was rising quickly. The three of us made it to their truck and they got me out. Meanwhile a neighbors regular pickup truck had been flipped by the water because they hadn't parked on higher ground. Not a fun night, lived at my store for about a week till I could return to the house.
I fixed everything on the house after that flood, repainted the inside, new plumbing fixtures, repaired and reinforced the river wall, basement walls & piers, so it was nicer than it'd ever been while she owned it. I told her in Dec. "I'm moving to FL now, sell the house now while everything's perfect". She hesitated and the following spring an even higher flood came which was over a foot deep on the first floor damaging all the flooring, kitchen cabinets, 1st floor bathroom, the Steinway piano, washer/dryer, etc. etc. My basement work had performed admirably but the additional flood height wrecked the 1st floor of the place.
As time goes by more and more roads, parking lots, and other man made features increase the flash flood potential of our river systems. So what was once considered a hundred year storm situation may no longer apply. Wouldn't surprise me a bit if the building of new structures isn't allowed in the area where the trailer is now even up on piers or stilts. I wouldn't do it, it's just problems all the way through. If you do decide to do it, get a hatch in the roof that can be opened from the inside, you may save someone's life one day.
This is the house. The floods while I was there didn't quite get up to the deck. Flood after I left was about 2 feet over the deck.
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I just got back from Kitty Hawk NC, almost every house down there is up on stilts. There was a house down there that was raised up higher on a bunch of cribbing, I guess the piers under it are getting re-done. I'm assuming with enough blocks and jacks, you could raise the trailer up and set the piers under it. 
