building a barn first curve ball

[Rockbadchild]

I am/was currency in the process and gathering quotes and getting my barn drawing done for the barn, we are planning to start this summer. Also got the ball rolling with the building permits and restriction and what not. My first curve ball came reel quick, the only part accessible by vehicle of my land is under a flood zone, for one I didn't know we had these zone which make my whole land useless, the existing house and garage is in this so call flood zone which is 3 meter above the existing creek bank and extend 400ft on each side, the creek is 2 feet deep, 2 feet wide and dry most of the year. I am currently contesting this with the city. I am not happy my lawyer didn't informed me of this during the purchase... anyhow,

I have some exposure to these calculation within my education but no field experience.
I send the elevation differences with the flood zone a and creek watershed basin with the highest recoded rainfall (bigger then the region 100 year storm) and the creek natural basin is well capable (with its natural banks) to take care of this biggest recorded rainfall even without creek outflows and soil, vegetal absorption and retention, so I didn't bother kept going to the rest of the calculation with all the other variable like soil abortion, runoff coefficient, watershead slope and roughness coefficients and antecedent condition variables since these would only make my case more obvious, I did the worse case scenario one can make and it pass so no further investigation needed is my reasoning ... I proposed a new outline with these two straight froward calculation and send it out to the city. The city lady didn't know what I was talking about despite explaining it dummy proof and sent it to their consultant for referral. so now I wait.

so what can I expect (answer and time) ? will it be a no brainier ? will I need a detail survey and study done ?, what are your thought and experience on the matter ?

pink = 230 elevation
red= city flood zone
sky blue= natural creek flood zone
dark blue=creek
creek bank elevation 227
I proposed to have the sky blue as flood zone, I would settle for the pink line.

the barn we want to build

 

[dodge man]

What is the source of the flood zone? FEMA? I’ve done some flood elevations over the years. If it’s fema you can do what is called a LOMA. I think that stands for letter of map amendment. As a land surveyor I could do those and sign them and some or all of your property would be removed. For example if you house lowest level is elevation is 300 and the flood elevation is 290 they would remove your house. Same thing where your proposed barn is.

 

[CloverKnollFarms]

#1. Pretty sure in my country it’s not legal to not disclose that the land is a flood zone. #2. I had no idea you could draw up your own and ask them to accept it. Insurance companies probably wouldn’t be too keen on that. Isn’t there already a science applied to it?

 

[Rockbadchild]

What is the source of the flood zone? FEMA? I’ve done some flood elevations over the years. If it’s fema you can do what is called a LOMA. I think that stands for letter of map amendment. As a land surveyor I could do those and sign them and some or all of your property would be removed. For example if you house lowest level is elevation is 300 and the flood elevation is 290 they would remove your house. Same thing where your proposed barn is.

thanks for the response,

I asked where these limit came from and what they where based on, they said don’t know and don’t know, i ask who was in charged of them, was told the city is responsible for their flood limits and not sure if any other party are involved. I ask why the house is within it if it’s a flood zone she said the flood zone limit came after… she also said most of the town is within it and some people has built within it but didn’t seem to know about the process, she told to to make my case and see if it could be changed…

it is … how you call it bureaucracy at its finest.

 

[Rockbadchild]

#1. Pretty sure in my country it’s not legal to not disclose that the land is a flood zone. #2. I had no idea you could draw up your own and ask them to accept it. Insurance companies probably wouldn’t be too keen on that. Isn’t there already a science applied to it?

will check on that with my lawyer.

they certainly didn’t apply it in the first place … if you go back and look at the interaction between the red line (city flood zone) and the pink line (elevation line) and tell me if they apply any sciences to it …

there is a equation which I did at it’s simplest form … total area of the water system watersheds x total precipitation of the 100 year storm = volume of water

then simply took the reservoir area and it’s banks height and it is the same volume so in my mind it is cristal clear and good to go …

what is the relation between building permits and insurance… don’t insure me for flood and call it a day

 

[dodge man]

I think fema flood maps are viewable on line. I’d look at that and compare to what you are looking at from the city.

 

[ericm979]

some counties have GIS on line which shows flood maps.

 

[Rockbadchild]

I think fema flood maps are viewable on line. I’d look at that and compare to what you are looking at from the city.

Fema is an American thing but i will look for the canadian equivalent

 

[orezok]

Op is in Canada. FEMA is in US

 

[CloverKnollFarms]

Here we can build in a flood zone if we want... Good luck insuring it though.