Drainage plans

[Hobby_Man22]

I had a meeting today with the building department and they said I needed a drainage plan for my 2 acre lot in order to place my 50x60 building. I guess I can just make a small drainage ditch around the perimeter of the building and then route it out towards the front of the property then a single ditch 400ft along the inside of the property line down to the main roadway? They didn't actually go out to the lot, just looked at it on the map, but I'm pretty sure the lot already drains towards the road for the most part. I don't really see any if this kind of stuff on any of the other lots around me. Maybe I'm misunderstanding. I get that the idea is that I don't put water onto the neighbors property, but maybe I'm making this more complicated than necessary. The main thing is the water HAS to flow towards the main road, not the little private dirt easement that i and the neighbors use. Seems kind of dumb. The easement has a ditch and flows to the main road.

 

[Hobby_Man22]

Maybe I'm misunderstanding something though unless they want the whole lot regraded with dirt brought in.

 

[yeldogt]

Actually, a drainage plan is just that ..... it's a full plan of the topograply of the property with the building situated. It takes into account the lot size and the amount of water that the building will now displace onto less soil.

There is a lot that goes into the "plan" -- this is not "what do you plan to do with the water -- send it to the street"

You may need to do a soil displacement plan with the drainage plan second --- with two acres --- did he say "stormwater management" at all.

You may have to go back and ask if he can show you what he wants ..

 

[wssix99]

I think this might be a golden opportunity to incorporate a moat into your shop. Become a Garage Journal legend! (It also gives the sharks a place to swim.)

 

[Hobby_Man22]

Actually, a drainage plan is just that ..... it's a full plan of the topograply of the property with the building situated. It takes into account the lot size and the amount of water that the building will now displace onto less soil.

There is a lot that goes into the "plan" -- this is not "what do you plan to do with the water -- send it to the street"

You may need to do a soil displacement plan with the drainage plan second --- with two acres --- did he say "stormwater management" at all.

You may have to go back and ask if he can show you what he wants ..

Is it possible not much needs to be done as far as grading the lot and making sure it drains into towards the street? The lot is flat as can be atleast to the human eye.

 

[FMB4]

It's always something.

 

[Hobby_Man22]

It's always something.

It's not my fault.

 

[Hobby_Man22]

The neighbor just had a house built a month ago and their lot drains into the private road/easement and I don't see anything special done. I'm sure it drains into the neighbors lot just by looking at it.

 

[Hobby_Man22]

I'm not really sure why the city seemed to make this like a ginormous task, not that I know a ton about dirt work, but I don't see this taking more than 3 or 4 days with someone who knows what they're doing. I don't understand why the contractor didn't mention this when he came out to look at my lot either though. He made it sound like they would just give me the permit almost immediately. I love how everyone is always out to screw the other person .

 

[yeldogt]

Grading plan // disturbance plan // stormwater management plan --- these are all parts of permits that are often required to build on a lot. That's why I said in another post that you need to find out what is needed and you may want to check on the septic and well. Even if you don't ever instal it -- once they are permited the land value increases. Put the building in a spot where it's in the way of the potential well or septic -- now a future buyer has to remove the building. So the building is not a plus -- it's a negative.

In many areas you can't transport water to the street -- you have to manage it on the lot.

That's why you need to go back and ask to see what he is talking about --- he may show you someones plan.

 

[Hobby_Man22]

Grading plan // disturbance plan // stormwater management plan --- these are all parts of permits that are often required to build on a lot. That's why I said in another post that you need to find out what is needed and you may want to check on the septic and well. Even if you don't ever instal it -- once they are permited the land value increases. Put the building in a spot where it's in the way of the potential well or septic -- now a future buyer has to remove the building. So the building is not a plus -- it's a negative.

In many areas you can't transport water to the street -- you have to manage it on the lot.

That's why you need to go back and ask to see what he is talking about --- he may show you someones plan.

So a pond would be another option?

 

[Hobby_Man22]

So a pond would be another option?

Or does even the pond have to be routed to the street?

 

[FredWanaker]

did the guy give you his card? Maybe call or email him asking if he is telling you that they will require a grading plan, or if he was just thinking out loud? The lot used to absorb a certain amount of water, now there will be an impervious roof shedding the water. If he just wants to know where it will go then point out there is already an X foot deep and Y feet wide drainage ditch that picks up the water and carries it to the road ditch. He may say, yeah that will be fine, or he may say we will need a calculation how much more water that ditch will carry now.

 

[tarmy]

Most places require a professional…like a civil engineer to do the plan…and more importantry, sign a letter that the drainage was done correctly and conforms to the plan. Usually, local jurisdictions have drainage rules/ordinances that are to protect neighboring property and stream/roads.

 

[Hobby_Man22]

did the guy give you his card? Maybe call or email him asking if he is telling you that they will require a grading plan, or if he was just thinking out loud? The lot used to absorb a certain amount of water, now there will be an impervious roof shedding the water. If he just wants to know where it will go then point out there is already an X foot deep and Y feet wide drainage ditch that picks up the water and carries it to the road ditch. He may say, yeah that will be fine, or he may say we will need a calculation how much more water that ditch will carry now.

No but I can call the city and leave a message. He was adamant about no water flowing to the private road, although i didn't think to say but how do you think all the neighbors houses up stream of me drain?

 

[Showkey]

Perfect time to fix that flooding of the septic tank when it rains mentioned in prior posts.
That might be effecting the well quality issue mentioned in prior posts.

Does the road actually have a drainage ditch ?
Suspect the next question is erosion control and holding the soil In the plan.

Ponds formation in many areas require another permit/plan process…..which usually requires a another plan to when plan when the pond over flows ( fills) ……it’s does not flood the home, buildings, the septic, well, neighbors property, the road etc.

Dig pond and your well or the neighbors well does dry because you changed the Aquaphor ………..you have another services of problem.

 

[yeldogt]

Sometimes you need to build stormwater management ..... big tank with rock bottom. They can be 25k easy.

My grading plan was 16k .... I did not need stormwater as the improvements did not reach the next level over what was on the property.

I did need a soil disturbance permit .... My memory this kicks in around us at 2k feet of disturbance. Easy to hit as a truck going over dirt is a disturbance

 

[Hobby_Man22]

Perfect time to fix that flooding of the septic tank when it rains mentioned in prior posts.
That might be effecting the well quality issue mentioned in prior posts.

Does the road actually have a drainage ditch ?
Suspect the next question is erosion control and holding the soil In the plan.

Ponds formation in many areas require another permit/plan process…..which usually requires a another plan to when plan when the pond over flows ( fills) ……it’s does not flood the home, buildings, the septic, well, neighbors property, the road etc.

It does on the easement where he said I wasn't allowed to let the water to drain, so even the current building that's on it doesn't follow what he was telling me today about keeping the water within the property lines and that was just built in 2018. The ditch also kind of tapers off halfway down in the area where the lot is empty, but still flows water from the neighbors house to the main street. Kind of a shame they didn't just go out there and look at it instead of google earth. The current house and building has all the water either flowing to the backside and into a small ditch to the main road or to the front also to the main road. None of this keep it within the property lines bs. Well the backside is within the property lines. I think the previous owner went back after the fact and dug a ditch in that easement that nobody wants to claim as theirs. That's what it sounds like talking to the neighbors.

 

[nicholsmf]

I would sit down and have a talk with him about exactly what is required. It may be very simple and something that will naturally happen during the dirt work for the building process. Or, it may be a $50K adventure. No way to know without nailing down the requirements and no reason to worry about it until then.

I was fortunate when I built my shop that it sits uphill from, and 15 feet from, a huge concrete stormwater ditch that is my property line. Nothing required as all displaced water goes into a preexisting ditch designed for that purpose.

 

[kwb]

Around here you have to contain runoff of new structures to the property. Making it the local storm sewers problem probably isn't going to fly.

 

[Hobby_Man22]

Around here you have to contain runoff of new structures to the property. Making it the local storm sewers problem probably isn't going to fly.

That's what he said. It had to be routed to the main city roadway ditch. I was surprised they were okay with that. Nothing like overloading the city drainage system.

 

[Hobby_Man22]

I would sit down and have a talk with him about exactly what is required. It may be very simple and something that will naturally happen during the dirt work for the building process. Or, it may be a $50K adventure. No way to know without nailing down the requirements and no reason to worry about it until then.

I was fortunate when I built my shop that it sits uphill from, and 15 feet from, a huge concrete stormwater ditch that is my property line. Nothing required as all displaced water goes into a preexisting ditch designed for that purpose.

I think the high spot is where I want to put my building, then slopes down from there, otherwise i'd be seeing the water moving the other direction in a heavy rain.

 

[Walkers]

Usually a drainage plan includes you hiring an engineer to survey the lot elevations, create a topo map, and decide where the water comes from, where it goes to, and figure out what should happen in between. Usually the cost is about 5 grand.

 

[Hobby_Man22]

Usually a drainage plan includes you hiring an engineer to survey the lot elevations, create a topo map, and decide where the water comes from, where it goes to, and figure out what should happen in between. Usually the cost is about 5 grand.

That doesn't include doing the work though does it?

 

[Hobby_Man22]

I could have sworn a drainage plan wasn't needed for anything less than a 5000 sq foot of building on my lot.

 

[Walkers]

That doesn't include doing the work though does it?

No, just the plan. I’m pretty sure a kickback goes back to the county/city guy who tells you that you need a drainage plan.

 

[Hobby_Man22]

In the frequently asked questions on my cities website it says:

Will I need a drainage/detention plan for my building project?
The city always requires a grading plan for a new development. Drainage plans are required when the building is considered large over 5000 sq ft. (What's the difference between drainage and grading?) My total building square footage added together is 4700


Do I need a storm water pollution plan (SWPPP) for my building project?
A stormwater pollution plan is required for projects over 1 acre in size requiring a state filed SWPPP. (I don't understand this) My lot is 2.11 acres but the total building size I want to add is 3000 square feet. (A 3000 sq foot building isn't anywhere close to an acre sized project) Even adding all the structures together only adds up to 4700. I would imagine they're talking about something like a church with a huge parking lot etc. I also don't have any non permeable surfaces like a concrete driveway. It's all crushed concrete.


I don't see how any of this applies to me and the way they have the first question worded is a bit confusing. This lot is already graded towards the main road. Where are they getting all this don't polute the neighbors yard with storm runoff if it says what I have stated above?

 

[Hobby_Man22]

I think a grading plan is probably a bit more simple than making ditches all over the yard. Doesn't that mean I have to tear up all the grass? Can't I just have the foundation guy move the dirt around in a way that creates natural drainage in the direction they want it to go?

 

[yeldogt]

You are mixing up terms. Plan -- as this is speaking --- is not what you "plan" to do ... it's really an overview of the property and the current conditions showing what will be built and how this will sit within the lot. You are giving the officials the ability to see the property by looking at the plan -- the plan is many pages showing different aspects. What it will do to the lot and how you will protect the surrounding area while under construction and what the final outcome. Disturbance permits typically have within them the grading plan -- draining permit sounds like our stormwater management. It's not as simple as may plan is "I'm going to put a drain around the building"

All of these permits show the officials what part of the lot you will be disturbing -- what is the current conditions and what will you be changing. Sometimes you have to restore .... where is the building -- where will the water go from the roof? How much hard scape will be added to what is there .... what is the total hardscape/ impervious and how will this affect the water run off.

All of the items have square foot triggers that are different depending on location ...

Having the ability to dump the water to the street and the towns stormwater control saves a lot ... you don't need a tank it seems or god forbid a pond -- very expensive today.

I have had to build swales -- well one. It had to be designed just like any other item on the "plan" --- it was like designing a roof gutter. How much water in the 100 year flood -- I had to do a 2'x2' grate and 8" pipe from the back of the property .... just getting the grate installed was in the 3k -- and all the piping was more.

It sounds like you will need professional help ... in my area it's better to hire engineers --- but some survey companies can do it. Engineers have a bit more weight. You also have to normally put down an escrow for the town to pay for the review on that side. YOU need to ask more questions and find out what they want ....

 

[sjvicker]

I'm with the poster above that said give them a call and ask for an example of a "grading plan" since you're under the 5000sqft of building. This may be really straightforward and it may be complex. Say something to the effect of "the pole barn I'm planning to build is under 5000sqft so I understand I need to submit a drainage plan. I have a decent elevation change from where I want to build to the ditch at the road, would a sketch showing the path of water runoff suffice?"

I was required to present plans to my city when converting a bedroom to a bathroom and I spent a ton of time drawing them out in CAD as best as I could. It turns out I probably would have been fine with a sketch on graph paper and my city is known for having an arduous permitting process.

They've told you where the water needs to go (the ditch) and you've stated your building will be on the high spot. There's a chance they just want a sketch with arrows showing how the water gets from your roof to that ditch.

 

[Hobby_Man22]

Okay I asked. They want a site grading or drainage plan showing no adverse impact to adjacent properties.

 

[jmdirk]

i went through similar BS on my build. I'm on 7 acres and built a 1200 sq ft garage. Sent in the permit application and the city comes back and says I need a "drainage plan". I'm rural, surrounded by cornfields and woodland, but still within the city limits. And the city requires all projects need a drainage plan.

I called around a bit and one civil engineering firm even gave me the phone number of the city manager and told me to call him and see if I could get a waiver given that there's no other development around me. The property adjacent to the garage is woodland. Front of the property is a road with a ditch. The other two property lines are municipal drains. City manager told me the only way he could waive the requirement is if I was building further from the property line.

Ended up hiring a local surveying firm to do the drainage plan. Couple guys came out, did a topo survey of the build area and the resulting 'drainage plan' was basically the existing topography, a note saying the top of foundation was going to be 6" above grade (minimum required by code here) and a few indicators showing the grade was going to slope away from the garage.

It wasn't that expensive. It was more that it cost me about a month delay in getting my permit.

 

[Hobby_Man22]

i went through similar BS on my build. I'm on 7 acres and built a 1200 sq ft garage. Sent in the permit application and the city comes back and says I need a "drainage plan". I'm rural, surrounded by cornfields and woodland, but still within the city limits. And the city requires all projects need a drainage plan.

I called around a bit and one civil engineering firm even gave me the phone number of the city manager and told me to call him and see if I could get a waiver given that there's no other development around me. The property adjacent to the garage is woodland. Front of the property is a road with a ditch. The other two property lines are municipal drains. City manager told me the only way he could waive the requirement is if I was building further from the property line.

Ended up hiring a local surveying firm to do the drainage plan. Couple guys came out, did a topo survey of the build area and the resulting 'drainage plan' was basically the existing topography, a note saying the top of foundation was going to be 6" above grade (minimum required by code here) and a few indicators showing the grade was going to slope away from the garage.

It wasn't that expensive. It was more that it cost me about a month delay in getting my permit.

I think it's ridiculous. 98,000 square foot lot and they're worried about a 3,000 square foot building. This was the whole point of buying this 2 acre lot.

 

[Hobby_Man22]

I'm going to talk to my engineer friend and see what he says. He's a pretty reasonable guy and isn't going to get carried away with whatever it is they need. Luckily he has a good relationship with my building department. I'll bet 100 bucks he'll say my lot is just fine how it is. Lol

 

[Bretny]

I think it's ridiculous. 98,000 square foot lot and they're worried about a 3,000 square foot building. This was the whole point of buying this 2 acre lot.

The point of buying a 2ac lot is so you can put your building where you want on it and not only in one spot due to setbacks or other laws...that dosnt mean you dont have hoops to jump through.

 

[yeldogt]

i went through similar BS on my build. I'm on 7 acres and built a 1200 sq ft garage. Sent in the permit application and the city comes back and says I need a "drainage plan". I'm rural, surrounded by cornfields and woodland, but still within the city limits. And the city requires all projects need a drainage plan.

I called around a bit and one civil engineering firm even gave me the phone number of the city manager and told me to call him and see if I could get a waiver given that there's no other development around me. The property adjacent to the garage is woodland. Front of the property is a road with a ditch. The other two property lines are municipal drains. City manager told me the only way he could waive the requirement is if I was building further from the property line.

Ended up hiring a local surveying firm to do the drainage plan. Couple guys came out, did a topo survey of the build area and the resulting 'drainage plan' was basically the existing topography, a note saying the top of foundation was going to be 6" above grade (minimum required by code here) and a few indicators showing the grade was going to slope away from the garage.

It wasn't that expensive. It was more that it cost me about a month delay in getting my permit.

This is the process one has to go through ..... getting information from people who know the rules and what in the minimum to get past the rules. The OP keeps acting like this is ridiculous -- well it may be. It's only going to grow ... in the end someone has to sign off on it (the code official) and many times the local official wants someone else to have a stamp and be responsible.

The OP also seems less interested in making sure other things are in order ---- depending on his age he may regret that when he goes to sell the property in 10 or 20 years.

 

[FredWanaker]

Okay I asked. They want a site grading or drainage plan showing no adverse impact to adjacent properties.

So that is a definitive answer and talking with your friend should help. Good luck with the project. You have now covered the first couple miles of the journey.

 

[Hobby_Man22]

So that is a definitive answer and talking with your friend should help. Good luck with the project. You have now covered the first couple miles of the journey.

Well I think once they have an engineered plan, showing what needs to be done or that everything looks okay the city inspector doesn't really have a say anymore because he's not an engineer.

 

[Hobby_Man22]

i went through similar BS on my build. I'm on 7 acres and built a 1200 sq ft garage. Sent in the permit application and the city comes back and says I need a "drainage plan". I'm rural, surrounded by cornfields and woodland, but still within the city limits. And the city requires all projects need a drainage plan.

I called around a bit and one civil engineering firm even gave me the phone number of the city manager and told me to call him and see if I could get a waiver given that there's no other development around me. The property adjacent to the garage is woodland. Front of the property is a road with a ditch. The other two property lines are municipal drains. City manager told me the only way he could waive the requirement is if I was building further from the property line.

Ended up hiring a local surveying firm to do the drainage plan. Couple guys came out, did a topo survey of the build area and the resulting 'drainage plan' was basically the existing topography, a note saying the top of foundation was going to be 6" above grade (minimum required by code here) and a few indicators showing the grade was going to slope away from the garage.

It wasn't that expensive. It was more that it cost me about a month delay in getting my permit.

How much was it? Where did they want you to drain the water.

 

[yeldogt]

Well I think once they have an engineered plan, showing what needs to be done or that everything looks okay the city inspector doesn't really have a say anymore because he's not an engineer.

Yes, they have a say. Trust me -- they have a say and it is much better if they are an engineer as you have to prove them wrong if they don't agree. They will not be an engineer.

Having to pay a professional to prove that a code official is not correct is sadly all too common. Again -- it all depends on how much the want.

Also: For my last project -- just as projects prior I had to put 5k in escrow for the town. They uses this money to review you plans and make site visits. The basic permit cost is only for precessing .... they actual review is done by the town engineer and attorney on your dime from the escrow.