Garage rainwater gutter- pending work!

sujsuj

The only remaining task from my previous garage renovation is redirecting rainwater to a proper drainage pit. This is critical because, on multiple occasions during heavy rain, my garage has flooded due to rainwater from the roof accumulating around it. Upon inspection, I found that the previous gutter pipe was not properly connected to a drainage pit.

Currently, I have water coming from both sides of the garage. Would it be better to combine the drainage from both sides into one pipe, routing it from the right side to the left before directing it to a pit (which still needs to be constructed)? Or is it more effective to have separate pipes from each side, each leading directly to the pit?

I plan to dig a pit 4-5 meters away from the garage. The plan is to excavate a large hole, install plastic crates for water dispersion, and have the pipes drain into that.

Prior to the renovation:

• The left-side pipe was draining directly into a muddy area, but it was not properly managed, which contributed to flooding.
• The right-side pipe ended as a hanging outlet discharging water onto a concrete surface, further adding to the flooding issue.

Any advice or recommendations on the best approach to manage this drainage effectively would be greatly appreciated. Thank you!

35har1old

sujsuj said:

The only remaining task from my previous garage renovation is redirecting rainwater to a proper drainage pit. This is critical because, on multiple occasions during heavy rain, my garage has flooded due to rainwater from the roof accumulating around it. Upon inspection, I found that the previous gutter pipe was not properly connected to a drainage pit.

Currently, I have water coming from both sides of the garage. Would it be better to combine the drainage from both sides into one pipe, routing it from the right side to the left before directing it to a pit (which still needs to be constructed)? Or is it more effective to have separate pipes from each side, each leading directly to the pit?

I plan to dig a pit 4-5 meters away from the garage. The plan is to excavate a large hole, install plastic crates for water dispersion, and have the pipes drain into that.

Prior to the renovation:

• The left-side pipe was draining directly into a muddy area, but it was not properly managed, which contributed to flooding.
• The right-side pipe ended as a hanging outlet discharging water onto a concrete surface, further adding to the flooding issue.

Any advice or recommendations on the best approach to manage this drainage effectively would be greatly appreciated. Thank you!

It all depends what type of sub soil and the natural water table
The bottom of the pit should be above the natural water table.
Perhaps the pit should be as far away as possible and use the trench as well for added drainage 

ThisIsWeird

How much land do you have, does it slope, and how far away could you install the soakaways? What's over the boundary - any neighbour who could be affected?
A possible angle to handling this issue could be to 'manage' the runoff from the roof by installing a suitable number of large butts - I'm sure you can pick up sizeable drums on Fb if you look long enough, especially if you are in a farming area - and these would collect and constantly release a manageable amount of water that your land can absorb, or to your otherwise overwhelmable soakaways.
Ie, they fill as quickly as they need to, but have a permanently open, set output via a valve. Fill quick, drain slowly. A buffer. 
Or, build a wildlife pond

FreeBear

ThisIsWeird said: A possible angle to handling this issue could be to 'manage' the runoff from the roof by installing a suitable number of large butts - I'm sure you can pick up sizeable drums on Fb if you look long enough, especially if you are in a farming area

Or, build a wildlife pond

A neighbour uses a couple of 1000l IBCs to store rain water.

And some other ideas - https://www.rhs.org.uk/garden-features/rain-gardens

sujsuj

ThisIsWeird said:

How much land do you have, does it slope, and how far away could you install the soakaways? What's over the boundary - any neighbour who could be affected?
A possible angle to handling this issue could be to 'manage' the runoff from the roof by installing a suitable number of large butts - I'm sure you can pick up sizeable drums on Fb if you look long enough, especially if you are in a farming area - and these would collect and constantly release a manageable amount of water that your land can absorb, or to your otherwise overwhelmable soakaways.
Ie, they fill as quickly as they need to, but have a permanently open, set output via a valve. Fill quick, drain slowly. A buffer. 
Or, build a wildlife pond

20 years ago, there was a small pond where I believe the rainwater pipes used to drain. However, the pond no longer exists, as the previous owner turned it into lawn. The wastewater pipe, however, still ends underground, which has caused water blockages and minor flooding during heavy rains. I used drain rods to check if the rainwater pipes were draining properly into a soakaway, but it turns out they are not.

I have over an acre of land, and as you can see from the photo, there is a slight slope behind the garage leading toward the apple tree. beyond fence  is farmland, not other houses. I’m planning to dig a pit near the slope to help with drainage, or I may just allow the water to drain near the apple tree. I don’t think this would cause much harm.

Any thoughts? Thanks.

Sarahspangles

A pond or swale/ditch would be the agricultural solution. And possibly less expensive. You know from previous flooding the frequency and approximate volume.

ThisIsWeird

Near the apple tree seems to be both risky, to the tree, but also passing the issue close to your boundary. Ok, it might not matter if it's farmland, but then again it might...
With that much flat land, are you not tempted to make it a wee oasis? A lovely pond, as Sarah suggests, surrounded by trees and shrubs or whatever.
Either way, I think controlled flow may be the answer, as mentioned before. Have it draining at a ground-coping rate, possibly in more that one location.