Catch Basin Installation in Roseville, CA

Catch basin installation puts a grated box at the lowest point of your yard and connects it to a buried pipe that carries the water away. It is for Roseville homeowners who have one spot that floods after every rain, such as a lawn corner, a side yard or the foot of a patio.

What a catch basin does at a low spot

A catch basin is a small box set into the ground at the lowest point of a yard. It has a grate on top and a solid pipe leaving its side. Surface water runs to the grate, drops into the box, and the pipe carries it away. It is built for one problem: a single place where water collects and sits after every storm.

It collects water at one point. A channel drain catches a sheet of water along a line, and a French drain collects groundwater below the surface. A catch basin handles the puddle that always forms in the same place. It is one part of our wider yard drainage work, and on many lots we pair it with other fixes.

Catch basin parts: box, grate, outlet pipe and sump

A basin is a simple assembly, but each part affects how well it drains and how long it lasts.

The basin box

Most residential basins are molded plastic boxes, commonly 9, 12 or 18 inches square. Small boxes suit lawns and planting beds with light flow. Larger boxes take more water and hold more debris, which helps where a slope or a hard surface sends a lot of runoff to one spot. Precast concrete boxes are used where vehicles drive over the grate.

The grate

The grate controls how fast water gets in and how much weight it can carry. A standard plastic grate is fine in a lawn. Where a car will cross, the grate and box need a matching load rating, usually cast iron or heavy composite. A flat grate sits flush with the grass so a mower passes over it. A domed grate suits beds where mulch and leaves would cover a flat one.

Outlet pipe and fittings

Water leaves through a 3 or 4 inch solid pipe connected to a knockout in the side of the box. We usually use smooth-wall PVC because sediment washes through it and it holds a steady fall. Perforated pipe does not belong on the outlet. It would leak the water back into the ground beside the basin.

Sump and sediment trap

Some boxes have a deeper bottom below the outlet, called a sump. Grit and leaves settle there instead of washing into the pipe. The sump needs emptying now and then, but that is far easier than clearing a silted line.

Signs a low spot needs a catch basin

A catch basin is the right tool when water gathers at one point and has no way out. Common signs include:

If the whole yard is wet, or water spreads across a wide flat area, one basin will not fix it. That usually calls for regrading or a subsurface drain, and we will tell you so.

• A puddle that forms in the same place after every storm and lasts a day or more.
• A patch of soggy, dead or mossy grass while the rest of the lawn drains.
• Water collecting on a patio, a walkway or at the bottom of exterior steps.
• Runoff from a slope or a neighbour's yard ending in one corner of your lot.
• Silt or mud left behind in the same spot once the water finally soaks in.

Where the water goes after the catch basin

A basin only works if its outlet does. The pipe has to keep falling the whole way, commonly 1/8 to 1/4 inch per foot, and it has to end somewhere the water can leave.

Daylight outlet downhill

If the lot slopes away from the low spot, the pipe can run to lower ground and open out there. A pop-up emitter or a rock pad at the end keeps it from washing out the soil. This is the simplest option when the grade allows it.

Dry well on a flat lot

Where there is no lower ground, the pipe can feed a dry well. This is a buried chamber that holds the water and lets it soak into the soil slowly. It works best where the soil below the surface drains reasonably well.

Street or storm system

Where the property falls toward the street, the water can sometimes leave through a curb outlet. Rules on what may connect to the gutter or storm system vary, so we check with the city before planning that route.

How a catch basin installation goes, step by step

Most installs take one visit. The steps are the same whether the basin sits in a lawn or a gravel side yard.

Finding the true low point

We run a hose to watch where the water goes. Then we use a level or a laser to find the lowest spot and how much fall is available to the outlet. The basin goes where the water already wants to go.

Digging and setting the box

We dig the hole and set the box on a compacted gravel base so it does not sink. The grate sits slightly below the surrounding ground, so water runs into it instead of around it.

Trenching and laying the outlet pipe

A trench runs from the box to the outlet with a steady fall. We bed the pipe, check the slope along its length and make the connections. If a downspout line runs nearby, it can sometimes join the same pipe, as long as the pipe is sized for both.

Testing and restoring the surface

Before backfilling we pour water into the basin and watch it come out at the outlet. Then we backfill, compact and put back the sod, gravel or mulch so the grate sits neatly in the finished surface.

Catch basins on Roseville lots

Roseville has cool, wet winters and hot, dry summers. The wet season generally runs from October through April, so a low spot can sit dry for months and then hold water for much of the winter. A basin dug in summer still has to handle winter storms, so we size it for that flow, not for what the yard looks like in August.

Much of the city's housing is newer single-family development, often with narrow side yards between houses. A new fence, patio or planting bed can leave a corner with nowhere to drain, and a basin is often the neatest fix in a tight space. Homes on low ground near Dry Creek, Linda Creek, Secret Ravine or Cirby Creek need extra care when we plan where the outlet goes.

Keeping a catch basin clear

Lift the grate a couple of times a year, ideally before the first autumn storms and again in spring, and scoop out the leaves and silt. Make sure mulch, grass clippings or a doormat are not covering the grate.

If water still sits on the grate during a storm, the pipe may be clogged or crushed. Run a hose into the basin while someone watches the outlet. A blocked line can usually be cleared with a drain snake or jetter. A crushed or sagging section has to be dug up and relaid.