Does the Delta River Flood? (Deltana, Delta Junction: buy, store, deposit)

[msta999]

Does the Delta River around Delta Junction flood very often? And if it does, what areas get flooded? In other words, what areas would you "not" want to build or buy a home.

[heathen]

The lower Delta River (in the vicinity of the town) is extremely wide and braided, meaning excess water has plenty of room to spread out in. It would be pretty hard to imagine it flooding down here. The Tanana narrows down to a single channel at Big Delta and could concievably jam with ice and flood after a very cold winter, but I've never actually heard of that happening either (it rarely even freezes under the bridge).

We do get some weird "sheet flow" sometimes in spring, or in summer after very heavy rain, along the Alaska Highway southeast of Delta Jct (Note the huge empty culverts under the road between Delta and the Gerstle River). Jarvis Creek freezes to the bottom in winter, and the main channel is often clogged with ice in the spring, sending snowmelt off towards the Alcan. I think a map of possible flood zones along the Alcan exists. You might contact NRCS or the Soil and Water Conservation District in the Jarvis Building in Delta.

Generally speaking, we don't have a flooding problem here like they do in the single-channel lowland river valleys.

[Marty Van Diest]

Originally Posted by msta999

Does the Delta River flood?

Is it a river? Of course it floods. You just need to study a topo map to figure out where it will go if it floods. And braided rivers can still flood, but normally they erode an area first. So if you are on a flat area just above the river bed you will likely either be in a flood zone, or an erosion zone, unless you are on solid bedrock. If it's flat and it's gravel or topsoil, you have to ask yourself how it got that way. It likely is an old river bed...it's not called a sedimentary deposit for nothing.

So look at a topo map and buy a piece that is higher than the surrounding area and not in direct path of the river current, then you should be OK.

[heathen]

The Deltana region, south of the Tanana, is almost all alluvial deposit hundreds of feet thick. What rivers were capable of at the tail-end of the ice age isn't the same as now. That said, the comment about erosion near the riverbank is definetely true with the Delta River. If you build within a couple hundred yards of the riverbank, it's something to be concerned about unless the bank is re-enforced (which is the case with the town itself). Of course extreme erosion events are remotely possible, but the town's more likely to be burned to the ground in a forest fire than destroyed in a flood like that.

If you want to play it extra extra safe, there's ice age moraines in the area. I don't think much can touch you up there, except the cold east wind in winter... The main one crosses the Alcan just before Clearwater Road and crosses Nistler at the Mil-Tan intersection.

[gobrien]

I grew up in Delta Junction and to the best of my knowledge the Delta River has never caused a problem for residents. The grocery store and the entire business district on the Richardson Highway runs pretty close to the river. Contact these folks and I'm sure someone will know the history. Lots of longtime residents are still there.
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[RayinAK]

It's hard to predict when the Delta River will flood, but it's very possible since Delta Junction and that area of the river is downstream from the Black Rapids glazier. Who knows? It may take a hundred years, or ten. I agree with others here who have mentioned the it could flood. All you have to do is to look at the river as it flows through Delta Junction (you can do this from the air, or by looking at the topography on a map). All that sand and gravel bed right by Delta Junction is there for obvious reasons.
http://ak.water.usgs.gov/glaciology/...455%20Text.pdf
This one has a map of the area (the Delta River flows from right to left on the map):
http://www.dggs.alaska.gov/webpubs/u.../of95-0180.PDF