Before and After: The Drainage Project

I have mentioned many times before that our home sits at the low point of our street with everyone's water from both directions heading toward us in a big rainstorm.

A few summers back my brother came between semesters at his university and, with pickaxe in hand, dug a massive trench in the hardened clay soil. He lined the deep trench with river rocks and dubbed it "Trenchy" (said with a heavy French accent... emphasis on the "ee"... just because my brother said it that way).

"Trenchy" became the main dry river bed (or "arroyo") that led all other drainage efforts to the back corner of the property where a large county storm drain sits just on the other side of our property line. Each successive drainage project was heavily dependent on "Trenchy". One hidden drain system next to the house was even dubbed "Trenchy Junior".

As I've gone out during winter storms and observed the flow of rainwater since "Trenchy" was dug, I knew that there would be further adjustments over time once I figured out what we were doing with everything else back there. Last summer, I got into "Trenchy" and removed all the river rocks that had lined its banks. Most of the rocks were buried in layers of silt and their beauty was wasted with them buried like that. Since I was demolishing a large concrete slab adjacent to "Trenchy" it made more sense to remove all the river rock and replace them with large chunks of recycled concrete. Then the lovely river rocks could be used decoratively elsewhere around the garden, including filling the head of "Trenchy" with a bed of river rocks that supports the new flagstone sitting area that I put in next to the pond just last fall. The river rocks are great for draining the water out of the hidden "aquifer" that is under the flagstones built with crushed concrete, pea gravel, and sand. You can see the river rocks against the flagstones in the photo at right.


Once all the river rocks had been removed, I lined "Trenchy" with the concrete blocks at the same time as I demolished the concrete slab. I'd sledgehammer out chunks of concrete and then fling them into "Trenchy", going back later to more carefully arrange them.

Once "Trenchy" was lined completely, I installed large diameter french drains (those cylindrical white things in the photo at left) with branches going up mini trenches to take the floodwater away from the areas around the pond when it floods in heavy rain and quickly divert it down "Trenchy". The drains sit at a slight incline to shed the water toward the storm drain and they sit at the lowest point down the center of the trenches. I then took more chunks of recycled concrete and fill in up the sides of the french drains.

When that was done, it was time to hide everything under a thick layer of pea gravel and make "Trenchy" into "Super Secret Trenchy". We had 3 cubic yards of pea gravel delivered to our driveway from the local landscaping outfit, and I hauled wheelbarrow after wheelbarrow of gravel to the back to fill the foundation of a new garden shed as well as "Trenchy". The few wheelbarrows' full, my back was gone so Hubby kindly came out and finished up the pile for me.

With the pea gravel in place, the trench and french drains are now completely hidden. All you can see are pretty gravel paths that meander toward the back of the garden past raised planters made from recycled concrete where the dogwood (far right in the photo) and the olive (left foreground in the photo) have found their permanent homes.

Rainwater will now drain through the gravel into the french drains and be diverted to the county storm drain so we have less flooding under our house after heavy rainfall (hopefully I will be able to alleviate that all together with a few more minor tweaks farther up toward the house).

And the big bonuse is that I'll be able to walk around in the back garden without any difficulty even though it may be pouring rain. Before, it was like crossing multiple fjords back there. Now I won't even have to think twice!

The view from the back of the garden looking up toward the pond and house is now one of my favorites. The shadows lacing the path are being cast by the huge white oleander and the cherry and apricot tree conglomeration that I call "The Thicket" because the birds love to hang out in there where they feel safe. You can see the newly planted olive tree on the left in the raised planter with narcissus coming up around the base.

At the right is a 150 gallon horse trough that I used to house the goldfish for a while during renovations to the pond a couple of years ago. The horse trough will eventually become a part-sun water garden with a small recirculating waterfall in it. I'm really excited about that because up until now the only water plants I've been able to have in the pond are full-sun water plants. It will also serve as a nice little oasis to just sit and relax in the shade when the summer temperatures are scorching hot and soaring over 100° F (38°C).

But for now, I have more concrete to demolish, more planters to build, more paths to install, as well as a shed to assemble (well, Hubby is going to handle that part).