He Dug Two Trenches Across the Slope and Built a Tiered Retaining Wall That Stopped the Yard From Washing Away
Want a backyard slope that stops losing soil after every storm? This retaining wall project, originally shared by Reddit user @velolziraptor, turned an eroding side yard into a structured landscape with drainage, terraced planting beds, and curved retaining walls built entirely by hand over two weeks.
Instead of covering the hill with mulch and hoping the erosion slowed down, the project rebuilt the entire grade from the ground up. Deep trenches, drainage pipe, backfill stone, landscape fabric, and stacked retaining blocks transformed a collapsing slope into a layered system designed to control water and hold the hillside in place.
Erosion Had Started Taking Over the Entire Side Yard
The original slope had almost no structure holding the soil in place. Thin grass, exposed dirt, and uneven grading made the side yard look unfinished while runoff continued carving channels through the hill after rain.
The steep transition beside the house also created dead zones where weeds spread faster than grass could establish itself. The entire edge beside the foundation looked unstable compared to the flat lawn below.
Existing Grade Left the Hill Open to Washout
From the side angle, the elevation change becomes much clearer. Soil had already started collapsing near the center of the slope while weeds and patchy growth exposed how much movement the hill was experiencing over time.
The incline also pushed attention toward the HVAC unit and exposed foundation, making the side yard feel more like leftover space than part of the landscape design.
Layout Lines Marked the Entire New Wall System
Before digging started, spray paint and string lines mapped the future retaining wall footprint across the hill. Long trench paths showed where the lower retaining wall and drainage channels would eventually run.
The layout already introduced something the yard previously lacked: structure. Curved lines softened the slope while creating space for multiple planting levels instead of one continuous hill.
Trenching Changed the Backyard Into a Full Excavation Zone
Once excavation began, the project shifted from landscaping into major structural work. Deep cuts through the sandy soil exposed how much material needed to be removed before the retaining wall base could even begin.
The trenches also revealed how carefully the drainage path needed to be controlled to keep future water pressure away from the wall system.
Excavation Created the Foundation for the Lower Wall
Large amounts of soil came out of the slope to create a compacted base area wide enough for retaining blocks, gravel, and drainage pipe. The trench depth showed this was not a surface-level landscaping project.
The cut also started flattening portions of the hill into future terraces, helping break the steep slope into more usable zones.
Dual Trenches Started Defining the Tiered Layout
With both trench lines excavated, the terraced design became visible for the first time. One retaining wall would support the upper slope while the lower wall created a second planting zone farther down the yard.
The layered structure immediately made the hillside feel more intentional instead of one large declining surface.
Heavy Landscape Fabric Wrapped the Entire Slope
Large sheets of landscape fabric covered the exposed soil before drainage stone and backfill went in. The black material separated soil from the drainage layer while helping stabilize the hillside behind the retaining walls.
This stage also showed how much of the retaining wall system depends on what stays hidden underground after the project finishes.
Gravel Base and Drainage Pipe Built the Core Structure
The first retaining blocks sat directly on compacted gravel while perforated drainage pipe ran behind the wall to redirect water away from the structure. Crushed stone filled the cavities around the pipe to improve drainage flow.
Instead of relying on stacked blocks alone, the wall used multiple drainage layers to reduce pressure buildup behind the retaining system.
Curved Retaining Blocks Started Reshaping the Hill
Once several courses were stacked, the retaining wall began changing the entire appearance of the side yard. The curved layout followed the slope naturally while creating stronger visual definition across the lawn.
The darker retaining blocks also introduced contrast against the pale grass and exposed soil.
Drainage Channels Ran Across Both Terrace Levels
Additional drainage pipe and gravel extended through the upper and lower sections of the retaining wall system. Every layer focused on controlling how water moved through the hill after rainfall.
This stage revealed how much infrastructure disappears behind the finished landscaping once mulch and plants are added.
Terraces Replaced the Original Uncontrolled Slope
After backfilling, the hill finally started resembling a finished landscape instead of an excavation site. The terraced shape created flat planting zones while reducing the visual harshness of the incline.
Even before planting, the wall system already made the side yard feel more stable and intentional.
Mulch and Gravel Defined the New Planting Beds
Fresh mulch, decorative gravel, and retaining caps cleaned up the entire structure while separating the planting areas from the lawn below. The gravel channels also visually reinforced the drainage paths built into the wall.
The stepped retaining edges helped the curved design feel custom-built instead of rigid or industrial.
Finished Retaining Walls Completely Changed the Side Yard
The completed landscape no longer looks like an erosion problem beside the house. Tiered planting beds, layered retaining walls, and curved transitions transformed the steep hill into a designed outdoor feature.
The retaining system also visually connected the house foundation to the lawn below instead of leaving a harsh slope between them.
Curved Terraces Made the Entire Backyard Feel More Finished
From the final wide angle, the retaining walls reshape how the entire property feels. The side yard now works as part of the landscape instead of wasted space beside the house.
The layered terraces, drainage stone, planting beds, and curved retaining blocks turned a collapsing slope into one of the strongest visual features in the backyard.
All image credits go to Reddit user @velolziraptor. Thanks for sharing.