Oklahoma Drainage and Sprinkler Repair – 405 203 9419

French Drain or Surface Drain

French Drain Benefit That I Never Expected

Take a minute and CLICK the above link.  It makes me smile!

Wow! Where to begin?

French Drain or Surface Drain can be a complicated decision.  Which one do you Need?

 

First you have to understand what they are and what they do.

Both have a similar initial purpose.  Their Job is to get water into a solid Drainpipe so it can flow underground to the place where you want it to go.  A French Drain and a Surface Drain are Both “INTAKES”.  They take standing or running water into a Drainage System.

Three Parts

A Drainage System has 3 Parts.  An INTAKE, A TRANSITION, and an EXIT.  An Intake is a French Drain or a Surface Drain that takes water into a Drainpipe as previously stated.   The Transition is the solid Drainpipe that takes the water where you want it to go.  And finally, an Exit is simply where the water leaves the pipe.

A French Drain Takes water in through a perforated pipe.  Typically for 4 or 6 ich pipe.  The pipe has thousands of little holes that allow water to enter the pipe and flow to the transition.  Some type of gravel or crushed stone surrounds the French Drainpipe.

The French Drainpipe in the above picture has a Black cloth filter around the 4-inch pipe and a white trench liner.  They are both semi permeable allowing water to pass into the pipe without dirt or debris clogging the pipe.  The trench is then filled with crushed limestone filling the trench and covering the pipe.

Surface Drains

A Surface Drain has a grate that sits on top of a basin.  Water comes in through the grate and goes directly into the Transition Drainpipe.

 

Surface Drains and French Drains are not created equal.  There are benefits and drawbacks to both.

Surface Drain Benefits:

Surface Drains look better when installed.

Surface Drains work better in small areas where the water is standing or moving slowly.

Surface Drain Drawbacks:

Surace Drains Don’t handle fast moving surface water across a broad area.  They take in some water, but the majority of the water just runs right around them or over the top of them.

Surface Drains can’t drain away or remove any kind of “Ground Water.”  Ground water has no way to get into the top of a Surface Drain.  If its muddy around a surface drain you have to wait until the heat or wind dries out the area.

French Drain Benefits:

French Drains can handle a much higher volume of water than a surface drain.

French Drains can intercept water with a higher velocity covering a broader area than a surface drain.

French Drains can also intercept ground water.  Most people don’t think about ground water moving.  It moves underground just like surface water moves above ground.  It just moves much slower.  A French Drain that is downhill from a muddy area will intercept and take in ground water moving downhill.  It enters the perforated pipe laterally underground and slowly enters the transition pipe and slowly flows or drips toward the exit point.  As a result the soil dry’s out much faster.

French Drain Drawbacks:

When first installed, a French Drain is not nearly as pretty as a surface drain.  Gravel running across your yard in a trench may not be appealing.

In sunny areas grass will grow over the French Drain over time.  This is perfectly fine.  It produces what is called a “Thatch Filter.” A Thatch Filter helps keep a French Drain clean along with the Pipe Filter and Trench Liner which also are installed to keep the French Drain clean and working well for Decades.

Don’t Cover a French Drain with Dirt

HOWEVER! YOU ABSOLUTELY CAN’T PUT DIRT ON TOP OF THE GRAVEL TO MAKE IT LOOK BETTER.  EMAGINE GASSING UP YOUR CAR BY OPENING UP YOUR GAS CAP AND THEN POURING THE GAS ON THE ROOF OF YOUR CAR.  A DROP OR TWO MIGHT MAKE IT INTO YOUR GAS TANK.  IN THE SAME WAY A DROP OR TWO OF SURFACE WATER MIGHT MAKE IT INTO THE FRENCH DRAIN.  DIRT ON TOP OF A FRENCH DRAIN WILL ELIMATE ITS ABILITY TO DRAIN SURFACE WATER.  IF YOUR DRAINAGE PROBLEM ONLY STEMS FROM GROUND WATER THEN PUT DIRT ON IT.  THIS IS CALLED A “CAPPED” FRENCH DRAIN.

In shaded areas grass will never grow over the gravel of the French drain.  There are two options.  Get creative with stone work and landscaping or live with the ugly French drain.

Here are some fancy French Drains that we have installed.