Markus10L - 3-12-2022 at 02:06 PM
Are French Drains and/or Foundation Drains prevalent in Baja Sur?
Trying not to sound silly since it is in a desert but has anyone had any issues with their house being on a slope during the rainy season?
pacificobob - 3-12-2022 at 05:30 PM
I find it remarkable how little thought is put into drainage in a lot of construction.
Yes, rain events are not super common...but often multiple inches fall in a brief time.
After the construction of our house, i had to do a fair amount of dirt work to channel the run-off away from some areas.
Markus10L - 3-12-2022 at 06:15 PM
I agree. I figure if there is one really rainy hurricane season might pay off to do a little digging and put in a few 3-4" PVC pipes and some pea
gravel just to be little precautious. I kind of figured it may not be something people are too concerned about or maybe there's not too much of a
need.
AKgringo - 3-12-2022 at 06:20 PM
At least you don't have to worry about getting your foundation and water lines below the frost line!
4x4abc - 3-12-2022 at 08:01 PM
from experience in BCS
french drains work great for showers, washing machine, kitchen etc
the plants love it
the rainwater between hurricane seasons does not even reach the french drains
during hurricane rain, so much water falls in a short period that ground and french drains are overwhelmed
if you have a wall around your property make sure it has large drain openings
otherwise you will have your house in a giant pool
happened to a friend of mine
3 ft of water in your house is bad for your furniture, tools, electrics etc
concrete work quality is extremely bad ( nobody here is vibrating concrete)
that leads to water intrusion and rusting of rebar at work joints
especially where the posts connect to the foundation
the strong hurricane winds topple many walls each time
they fail right above the foundation
I lost 300ft in one piece during Odile
make sure that flat surfaces (patio or roof) are actually draining the water away from the house
workers here do not understand the concept of water flowing DOWN
do not trust the promises of your contractor
inspect every day during building
I have 5 flat roof surfaces
all of them were mini pools after rain
a lot of additional work was needed to correct that
pacificobob - 3-13-2022 at 06:50 AM
Quite often the guys mixing the concrete with add a ton of water to the mix making it like grey broth in order to avoid voids in the pour. Vibrators
are used way too infrequently in favor of a super thin mix.
wilderone - 3-13-2022 at 08:53 AM
"being on a slope" is a different problem than flooding or drainage. With a slope you will have erosion over time, so inspect and project what
erosion will do in the long run. I saw a "Lots for Sale" development south of San Felipe and an aerial view would show that it's in an alluvial plain
- you could see how a wash was developing on each side of a house that clearly had been built on a site raised a little bit. Maybe protect the
foundation with low walls, berms, "riverbed" landscaping to divert rainwater. Look at a bigger picture and observe real time rainfall consequences.
pacificobob - 3-14-2022 at 08:56 AM
There are 3 gringo homes near me that are built in a "low spot".
Several old timers have told of 2 meters of water flowing like a river through the area back in the day. [100 year storm?]
Everything changes on the day it rains 20+ inches.
Markus10L - 3-14-2022 at 02:10 PM
Thanks! All good information. I am not in a "low spot" but was just thinking of erosion prevention with adding some french drains on the hill side but
I may just do as proposed and keep an eye on the property overtime to see if it is needed or just a waste of time and $$.
pacificobob - 3-15-2022 at 07:21 AM
I'm not sure how much water a 4inch drain pipe can handle. [ rain falling 1inch plus/hour] I prefer to make swales. Much higher capacity. Best of
luck with your drainage issues.
David K - 3-15-2022 at 08:36 AM
YES! Swales are excellent to slow the speed and redirect fast moving water.
Drain pipes (French/ gravel or surface grates) don't work until the water drops down to them.
Both systems would be wise in fast falling rain scenarios.
Clean the drain lines after the rain to remove any mud collection by flushing with clean water. 1% (1 ft. per 100') is the minimum drop for yard
drains, more is better, of course.
Markus10L - 3-18-2022 at 02:06 PM
Pacificobob- You are right... Swales are a superior resolution to any possible drainage issues. I have a cistern I could route the swales to. Thank
you for the advice also they look like a bit less work than the french drains.
David K- Thank you for the info! The property is on a slope which will make the 1 ft plus per 100 ft a much easier feat.
watizname - 3-19-2022 at 08:06 AM
In landscaped areas, swales are best. With outside flatwork, be sure the concrete is sloped to drain away from the house and out thru a gate or
walkway freely.