Drainage swale

Discussion in 'Landscape Architecture and Design' started by paul, Aug 27, 2002.

  1. paul

    paul Lawnsite Addict
    Posts: 1,625

    We are working on a soccer field, on one side is a new drainage swale it handles all the run off for the entire park (18 acres). We installed a erosion control blanket in the bottom of the swale but with the last rain we lost everything! I mean blanket, seed dirt......

    The blanket failed noted by the fragments of blanket left along the way. The swale is 700' long but only the bottom 6' is gone.

    Any Ideas to solve this delema?
     
  2. AGLA

    AGLA LawnSite Bronze Member
    Posts: 1,749

    Is there a way to slow the water down? Could it be less steep toward the outlet end or could there be stone or other material to slow down the water at least periodically?
    Maybe there could be a detention pond?
    Eighteen acres is a lot of runoff area. Was this designed by an engineer?
    Those are the questions that I would ask.
     
  3. paul

    paul Lawnsite Addict
    Posts: 1,625

    It was designed by an engineer, the LA posted in the contract documents that all straw bales be removed when seeding completed. Here's the tough part at the begining of the swale are 2 24" RCP pipes with precast FES. Water backs up but increases the velocity of the water. Swale ends up at a small creek so water quality is a major issue. TRMs maybe?
     
  4. Stonehenge

    Stonehenge LawnSite Bronze Member
    from Midwest
    Posts: 1,277

    This wouldn't happen to be the Fox Cities project, would it? And if it is, could it be at USA sports complex? I believe I saw them expanding the # of soccer fields they have.

    As for your dilemma, FES and TRM are GREK to me. Straw bales would've been my input, but it looks like that's out (unless the LA can be turned around). Did you use turf staples throughout the blanket?

    How about big roll sod stapled down?
     
  5. paul

    paul Lawnsite Addict
    Posts: 1,625

    FES= Flaired End Sections
    TRM= Turf Renforcment Mat

    Staples were placed 18" apart for high flow areas.
    the water moved the erosion blanket and dirt.
     
  6. lawnstudent

    lawnstudent LawnSite Senior Member
    Posts: 472

    Paul,

    soil erosion is affected by many factors such as a soil's texture, structure, slope, surface roughness, and soil cover. Slope actually has two components:grade and length. With a 700 foot length even a minor grade allows water to accelerate at the bottom of your swale and errode the swale. Have you thought of terracing the swale to reduce the effective length of the swale and slow the water? What is the % grade of the swale's slope?

    jim
     
  7. paul

    paul Lawnsite Addict
    Posts: 1,625

    the grade is less than 1%
     
  8. Lanelle

    Lanelle LawnSite Bronze Member
    Posts: 1,361

    I'm wondering if straw or coir wattles secured with wooden stakes across the swale in several places on the lower end would slow down the flow enough to prevent the scouring effect of the water flow. Surely Erosion Control Mag. has something that will be just right.
     
  9. paul

    paul Lawnsite Addict
    Posts: 1,625

    We are looking for a solution that will allow the water to flow without stopping it and killing the any seed, now I know that 100% coverage might not be possible. this swale was going to be mantained once or twice a year ( a slow growing fescue mix) was used to seed it. The over all effect was to allow the roots of the grass to renforce the the soil and allow water to flow over it.

    Main problem volume of water. even small rains at this point are a problem because no turf is able to become established.

    Soils, this area of the site has had a heavy amount of dirt moved to allow the field to be playable (leveled), under the top soil (6") is heavy clay/topsoil mix but compacted by heavy equipment.

    Elevation changes, the park has over 20' of elevation change by the time it starts this 700' >1% swale.
     
  10. GroundKprs

    GroundKprs LawnSite Bronze Member
    Posts: 1,969

    Plant wheat with your grass. Wheat germinates quickly and roots dramatically. Next spring before any mowing, wheat will be high above desireable grasses, then wick wheat with Roundup. Or just wait for wheat to die in summer; but that would require more mowing.

    Not sure of density to plant. I might be able to find out from an oldtimer nearby if you want the info. Wheat was used in seeding, for soil stabilization, until the 1920s. Its upright growth allows light for the desireable grasses.

    Pic is wheat 3-4 days after seed hits the ground. That's a quarter in the middle.

    wheat germa.jpg
     

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