Anonymous
Post 07/23/2025 23:41     Subject: Re:High flood factor what to do
Anonymous wrote:
Anonymous wrote:I don't think a storm drain 100ft away and a dried up stream 600 feet away is all that unusual for the less densely populated areas of MoCo. But the point is, this model predicts there is a 20% chance this year that half my land will flood when it has never happened in recorded history, so color me skeptical. I know everyone is worried about climate change but this seems like hysteria.

Anyways I found this neat elevator map for anyone interested. Really helpful to just point somewhere on a map and it gives the elevation.
https://apps.nationalmap.gov/viewer/



With the EPA potentially ending its ability to fight climate change and the horror we collectively witnessed in Texas recently I would really encourage you to do what you can now to understand your risk and protect your assets and your family. Vermont experienced horrible flooding a few years ago and it was totally unprecedented.

IMO there are more levers to pull to prevent fire from reaching your house than flood when it comes to things like removing vegetation, using certain building materials, removing kindling and leaves from the neighborhood landscape regularly, and even installing more fire hydrants.

I would strongly suggest flood insurance. It looks like the federal government (FEMA) will do significantly less in the coming years and states can only do so much.



Yeah, the problem is that the insurance companies are going to bail before you need it. And the federal government won't be there to make them come back. Stay far, far away from flood zones.
Anonymous
Post 07/23/2025 23:15     Subject: Re:High flood factor what to do
Anonymous wrote:First street predicts the ritz in Georgetown has a 20% chance of flooding this year....

And apparently large parts of AU park are in food zone.


We sold our Dupont English basement condo despite it being terrifically located and easy to rent out because flood maps said it would be under water in the next 20 years. We didn’t want to be stuck with it.
Anonymous
Post 07/23/2025 23:11     Subject: Re:High flood factor what to do
Anonymous wrote:I don't think a storm drain 100ft away and a dried up stream 600 feet away is all that unusual for the less densely populated areas of MoCo. But the point is, this model predicts there is a 20% chance this year that half my land will flood when it has never happened in recorded history, so color me skeptical. I know everyone is worried about climate change but this seems like hysteria.

Anyways I found this neat elevator map for anyone interested. Really helpful to just point somewhere on a map and it gives the elevation.
https://apps.nationalmap.gov/viewer/



With the EPA potentially ending its ability to fight climate change and the horror we collectively witnessed in Texas recently I would really encourage you to do what you can now to understand your risk and protect your assets and your family. Vermont experienced horrible flooding a few years ago and it was totally unprecedented.

IMO there are more levers to pull to prevent fire from reaching your house than flood when it comes to things like removing vegetation, using certain building materials, removing kindling and leaves from the neighborhood landscape regularly, and even installing more fire hydrants.

I would strongly suggest flood insurance. It looks like the federal government (FEMA) will do significantly less in the coming years and states can only do so much.

Anonymous
Post 07/23/2025 15:59     Subject: Re:High flood factor what to do
I don't think a storm drain 100ft away and a dried up stream 600 feet away is all that unusual for the less densely populated areas of MoCo. But the point is, this model predicts there is a 20% chance this year that half my land will flood when it has never happened in recorded history, so color me skeptical. I know everyone is worried about climate change but this seems like hysteria.

Anyways I found this neat elevator map for anyone interested. Really helpful to just point somewhere on a map and it gives the elevation.
https://apps.nationalmap.gov/viewer/

Anonymous
Post 07/23/2025 13:51     Subject: High flood factor what to do
Anonymous wrote:
Anonymous wrote:Look at federal flood maps, they’ll explain everything.

It’s probably based on probability and your neighbors may be on one side of a line that says 51 out of 100 times their house is okay and your is on the side that says 51 out of 100 it’s not - basically the same risk but you’re on the wrong side of the line.

Either way, there’s no way you can tell if something is right or wrong without looking at federal flood maps. It’s not a thing you can feel.


Federal flood maps have not been updated and are outdated, which is a big problem with erosion, climate change, and better forecasting capabilities.

The First Street assessment should provide you with information about this risk as it relates to your property, OP.


But to be clear, when we talk about federal maps being out-of-date, we're not talking about how maybe things have gotten better... assume your situation is worse than what the map shows. Best case it might be the same.
Anonymous
Post 07/23/2025 13:12     Subject: High flood factor what to do
Anonymous wrote:I just discovered that my house is rated 7/10 on the First Street flood factor that shows up on redfin. We bought the house about 3 years ago and I definitely do not remember it being rated that way then.

I have no idea what they base this stuff on but it seems inaccurate. My neighbors are all rated 1. We have had massive rain this year and we have never had water running or pooling near the house. Our old house which was at the bottom of a neighborhood hill had way more water issues and it is rated a 1/10. The only thing I can think of is that we have a storm drain easement on our property so there is a lot of water running out of that drain into the creek behind us but this drain is like 100 feet downwards from our house draining away. We are maybe 600 feet away from the creek, so not that close.

Question is, is there anything I can do? It seems so sketchy that this company gets to "predict" flooding and then ruin home values. Are we just screwed with our home value?


“storm drain easement” and “creek 600 feet away” are red flags. Small streams are very likely to flood during atmospheric river events and there are parts of the dc metro area that are prone to atmospheric rivers. Do you have flood insurance?
Anonymous
Post 07/23/2025 13:07     Subject: High flood factor what to do
Anonymous wrote:I took a look at First Street. Our house and the one we rented when we moved here, 2 doors west, are 1/10. Always dry basements.
The ones a few doors farther west are 7/10. Believable. One has a sump pump that ran constantly until it sold and new owners did french drains.
When we moved here 40 years ago I got USGS soil maps for fun. There is a change in the soil type right at that boundary. Also allegedly an underground stream per a very old man who had lived next door all his life when we met him then.
There are culverts at the running trail past there and a little stream, maybe emergence of the underground one in the woods there, feeding into 4 mi run. That is slightly downhill of us.

lol
Anonymous
Post 07/23/2025 12:58     Subject: High flood factor what to do
Anonymous wrote:The rating is for the entire property (and over the long term so it may be a risk estimated over the next 30 years). Older builders were not idiots and typically built on the highest elevation part of any parcel. So your house may be fine while an edge of the property may get water and it will still have a flood warning. If that is the case you can just explain when selling. You can get a land survey and argue with the rater for an adjustment but I don't know how effective that is.


I think the rating is for the property, but specifically structures on the property (structure could be something like a swimming pool). There should be a map that shows exactly where on the property the water will flow to and where it will come from…You shouldn’t have to guess about this or source info online. It should all be provided in the assessment.
Anonymous
Post 07/23/2025 12:53     Subject: High flood factor what to do
Anonymous wrote:Look at federal flood maps, they’ll explain everything.

It’s probably based on probability and your neighbors may be on one side of a line that says 51 out of 100 times their house is okay and your is on the side that says 51 out of 100 it’s not - basically the same risk but you’re on the wrong side of the line.

Either way, there’s no way you can tell if something is right or wrong without looking at federal flood maps. It’s not a thing you can feel.


Federal flood maps have not been updated and are outdated, which is a big problem with erosion, climate change, and better forecasting capabilities.

The First Street assessment should provide you with information about this risk as it relates to your property, OP.
Anonymous
Post 07/23/2025 12:52     Subject: High flood factor what to do
Anonymous wrote:
Anonymous wrote:Look at federal flood maps, they’ll explain everything.

It’s probably based on probability and your neighbors may be on one side of a line that says 51 out of 100 times their house is okay and your is on the side that says 51 out of 100 it’s not - basically the same risk but you’re on the wrong side of the line.

Either way, there’s no way you can tell if something is right or wrong without looking at federal flood maps. It’s not a thing you can feel.


The FEMA flood maps don't show flooding anywhere near my house.


I would take screenshots or somehow copy the maps because that data may be removed or destroyed by you know who.

Anonymous
Post 07/23/2025 12:17     Subject: Re:High flood factor what to do
Anonymous wrote:The first street maps actually show a lot of houses in MoCo subject to flooding. I feel like people are not aware this exists and will be surprised when they try to sell their house.

My issue with this company is that they do not really share their methodology, it is trying to predict the future, and yet it is negatively affecting home prices today based on this opaque methodology. There is also the obvious conflict of interest because they are longer a non profit and make money selling you flood insurance. And researching on reddit, people do not get anywhere trying to appeal their "Flood Factor" ratings.

How is this not a class action lawsuit waiting to happen?


Their methodology is on their website https://firststreet.org/research-library/flood-model-methodology
They have a ton of peer-reviewed publications as well.
However, input datasets aren't perfect. Plus incorporating flood risk reduction efforts at the local level is a massive challenge. I'm not sure what OP could do in the situation of a single house with questionable flood risk in a neighborhood of low risk. If I were in your situation I would look into what you can do to reduce flood risk on your property and document it so that info is available when you eventually sell your house. There are a lot of grants available for rain gardens, rain barrels and the like. Also, where would water on your property come from and what could you use to divert that water? You can do a lot to engineer the issue away especially if it's just your house and not neighboring houses with an issue.
Anonymous
Post 07/22/2025 18:24     Subject: High flood factor what to do
Anonymous wrote:Did you see the stories about flooding and water rescues in Tysons a week or so ago? And the GreatvFallss and MoCo floods? We barely got enough to wet the grass. They got inches in half an hour.


OP here, yes I know. I was in one of the heavy downpour areas. But no water near my house. My old house probably flooded though (because it often flooded so we ended up getting a French drain), because it was at the bottom of a hill but yet it has a 1/10 rating.
Anonymous
Post 07/22/2025 18:22     Subject: Re:High flood factor what to do
First street predicts the ritz in Georgetown has a 20% chance of flooding this year....

And apparently large parts of AU park are in food zone.
Anonymous
Post 07/22/2025 18:07     Subject: High flood factor what to do
Nothing?
Anonymous
Post 07/22/2025 17:58     Subject: High flood factor what to do
Did you see the stories about flooding and water rescues in Tysons a week or so ago? And the GreatvFallss and MoCo floods? We barely got enough to wet the grass. They got inches in half an hour.