RAPPIN’ ABOUT DOT

CDGRS MPAA RR 17 WARNING The following material may not be suitable for all Districts. Some of the photos used herein have come from people sitting in this room. Our intent here is NOT to offend anyone, but to promote thought and discussion.

Names and locations have been withheld to protect the innocent (and the guilty). DEFINING RIP-RAP

RIP-RAP:

Graded distribution of large size aggregate

Rip-rapped ditch DEFINING RIP-RAP The Engineer’s weapon of choice DEFINING RIP-RAP Highway maintenance manager’s idea of roadside beautification DEFINING RIP-RAP Sending interstellar communications DEFINING RIP-RAP Really Inappropriate Placement of Rock Armoring Practices DEFINING RIP-RAP GABIONS – Wire baskets filled with rip-rap

RIP RAP • PROPER PLACEMENT • OVER USE • MISUSE • ALTERNATIVES DEFINING RIP-RAP RIP-RAP : A permanent erosion resistant layer made of stones intended to protect soil from erosion in areas of concentrated runoff -EPA GENERAL DESIGN PRINCIPLES

•Stone must be hard, durable and angular

•Stone must be resistant to weathering and to water action

•Stone must be free from overburden, spoil and organic material GENERAL DESIGN PRINCIPLES

• Must be well graded from the smallest to the largest size specified instead of one uniform size

• The minimum weight of the stone should be 155 lbs/cu-ft RIPRAP SIZE CHART

NSA No. MAX D50 MIN V Max R-2 3 in. 1.5 in. 1 in. 4.5 ft/sec R-3 6 in. 3 in. 2 in. 6.5 ft/sec R-4 12 in. 6 in. 3 in. 9.0 ft/sec R-5 18 in. 9 in. 5 in. 11.5 ft/sec R-6 24 in. 12 in. 7 in. 13.0 ft/sec R-7 30 in. 15 in. 12 in. 14.5 ft/sec GENERAL DESIGN PRINCIPLES

•Riprap may be unstable on steep slopes greater than 2:1 (33% )

•The thickness of riprap layers should be 1 ½ or 2 times the maximum stone diameter GENERAL DESIGN PRINCIPLES

• A filter material is usually required between the rip-rap and underlying soil to prevent the soil from moving through the rip-rap.

This can be a filter cloth or a layer of gravel. GENERAL DESIGN PRINCIPLES

Main areas of riprap use in road construction is for roadside ditches or channels and outlets for stormwater culverts. ROADSIDE CHANNELS CHANNELS

PURPOSE –Keeps the water off the road for driving safety, and better maintenance of the road

–Controls the flow to eventually drain it away from the road and dissipate it CHANNELS DESIGN: – Permanent channels should be designed for 10 year storm or 2.75 cfs/acre – Avoid sharp turns or bends – Avoid very low gradients (< 1%) – Use appropriate lining (design calculations) • Procedures described in the Erosion and Sedimentation Control Manual and/or HEC15 • Checks velocity and shear stress based on slope, depth, width and n value Channel design

CHANNEL LINING INSTALLATION BEFORE LINING

CHANNEL WITH LINING

OUTLETS OUTLETS PURPOSE –Allows discharge of water without erosion downstream

–Dissipates energy and decreases velocity

–Stabilizes end of pipe OUTLETS DESIGN Erosion and Sedimentation Control Manual –Using the maximum discharge from the culvert, calculate a velocity –Based on the velocity, choose a rock size –From Fig. 21 & 22, determine length and width of the apron using riprap size, discharge and diameter of culvert –Rock needs to be placed that water doesn’t freefall at end of pipe but also doesn’t cause backwater

PROPER USE PROPER USE PROPER USE PERMITS

WATER OBSTRUCTION & ENCROACHMENT –Structure or activity in or along a watercourse, floodway or body of water • General Permit No. 3 • General Permit No. 4

NPDES –Earth disturbance between 1 and 5 acres with a point source or more than 5 acres GENERAL PERMIT NO. 3 BANK PROTECTION, BANK REHABILITATION & GRAVEL BAR REMOVAL

• Allows maximum of 500 feet of channel work • Cannot decrease normal channel width • No levee or channel relocation • Rock must be keyed in at the toe and at the ends PERMITS

WATER OBSTRUCTION & ENCROACHMENT –Structure or activity in or along a watercourse, floodway or body of water • General Permit No. 3 • General Permit No. 4

NPDES –Earth disturbance between 1 and 5 acres with a point source or more than 5 acres GENERAL PERMIT NO. 4 INTAKE AND OUTFALL STRUCTURES

• Cannot locate structure in a wetland • Can’t be used in or along HQ or EV streams • Maximum outfall size is 36 inches • Need to investigate drinking water intakes 5 miles downstream PERMITS

WATER OBSTRUCTION & ENCROACHMENT –Structure or activity in or along a watercourse, floodway or body of water • General Permit No. 3 • General Permit No. 4

NPDES –Earth disturbance between 1 and 5 acres with a point source or more than 5 acres NPDES PERMITS

• REQUIRES AN ADEQUATE EROSION AND SEDIMENT CONTROL PLAN BASED ON BMP’S

• A POST CONSTRUCTION STORMWATER MANAGEMENT PLAN MUST PROTECT WATER QUALITY, MAINTAIN INFILTRATION AND MINIMIZE POINT SOURCE DISCHARGES PROPER USE RIP RAP • PROPER PLACEMENT • OVER USE • MISUSE • ALTERNATIVES overuse

• COUNTER-PRODUCTIVE • EYESORE • $$$$$$$$ OVER USE

Low Gradient, Wide ditch, Why armor? OVER USE

Small stone will not hold!

If ditches carry to much water, more turnouts are required!

OVER USE

OVER USE

Erosion around rip-rap OVER USE

Pipe outlet Outlet obstruction clogs pipe with sediment

Road surface OVER USE

Grass is stable here

So why is this much rock necessary here?

Anchoring tree?

PIPE OUTLET OVER USE Why not use a small endwall and vegetation?

If turnouts carry too much water, more turnouts are required! OVER USE

NOTE clean stone below pipe outlet OVER USE Same pipe

NOTE sediment has filled in crevasses OVER USE

If ditches carry too much water, more turnouts are required! OVER USE

If ditches carry too much water, more turnouts are required! OVER USE

If ditches carry too much water, more turnouts are required! OVER USE OVER USE The start of a good headwall…

But it must have been close to lunchtime: dumping rip rap is easier and faster. RIP RAP • PROPER PLACEMENT • OVER USE • MISUSE • ALTERNATIVES Misuse

• FILLING DITCHES • SEDIMENT FILTRATION • REDUCING ACIDITY • STREAM CONFINEMENT MISUSE

1. Ditch filled with rip-rap 2. Rip-rap fills with sediment 3. Water runs on road (new ditch) MISUSE 1. Ditch filled with rip-rap 2. Water will attack bank, or run on roadway MISUSE 1. Ditch filled with rip-rap 2. Water will attack bank, or run on roadway MISUSE MISUSE MISUSE Rip-rap water filtration system?

Sediment will accumulate and may block pipe. MISUSE

Outlet protection or dump site???????? MISUSE

Erosion around rip-rap

Maintenance department sprays this rock to keep veg off! MISUSE Small stone will not be effective!

Bank will Erode around rip-rap MISUSE

Erosion around rip-rap MISUSE Rip-rap in channel causes erosion of surrounding bank. MISUSE

Rip-rap dumped in channel Stream cutting new channel around rip-rap MISUSE MISUSE Where would you rather fish? MISUSE MISUSE MISUSE RIP RAP • PROPER PLACEMENT • OVER USE • MISUSE • ALTERNATIVES ALTERNATIVES

• DITCH ELIMINATION –Raising the road –Removing the berm • FLOW REDUCTION • VEGETATION DITCH ELIMINATION

• PROMOTES: –Natural drainage patterns –Sheet Flow –Infiltration

• LESS OUTLETS TO STABILIZE!

• REDUCES MAINTENANCE! ESMP FILL ROAD CROSS-SECTION

IDEAL IL CROSS-SECTION SO P- O T

SUB-SOIL

ROADWAY ESMP FILL ROAD CROSS-SECTION

REDUCED BANK ELIMINATED HEIGHT BANK IL SO P- O T

FILL SUB-SOIL

ROADWAY ESMP FILL ROAD CROSS-SECTION PROJECT EXAMPLE ESMP FILL ROAD CROSS-SECTION PROJECT EXAMPLE ESMP FILL ROAD CROSS-SECTION PROJECT EXAMPLE ESMP FILL ROAD CROSS-SECTION PROJECT EXAMPLE ESMP FILL ROAD CROSS-SECTION PROJECT EXAMPLE EXAMPLE FILLING ROAD PROFILE PROJECT

BEFORE

AFTER Red Rose Road Cost Analysis

• Rip rap existing ditches $45,800 (excluding bank work and pipes)

Actually spent • Filling Road Profile (free shale on site) $32,760 (included bank work and pipes)

• Filling Road Profile (with bought shale) $36,575 (excluding bank work and pipes) ESMP FILL ROAD CROSS-SECTION

HOW: When you want to shift the road up-slope

IL SO P- O T

SUB-SOIL

ROADWAY ESMP FILL ROAD CROSS-SECTION

HOW: When you want to shift the road up-slope

IL SO P- O T ROADWAY

SUB-SOIL FILL Filling Road Cross-section BEFORE

1/2 Filling Road Cross-section BEFORE

2/2 TYPES OF FILL • Shale • Bank Run Gravel • Coarse Sand Stone • Quarry Rubble • Coal Combustion Byproducts • Road Construction Waste • Purchased Stone (2RC or 3A Modified) Berm Removal FLOW REDUCTION

• PROMOTES: –Natural drainage patterns –Sheet Flow –Infiltration

• REDUCED DITCH AND OUTLET EROSION

• PERMANENT! Flow Reduction Additional Crosspipes

Adding crosspipes reduces flow velocity and erosion. Flow Reduction Additional Turnouts

Water Flow

Water Flow

Adding turnouts reduces flow velocity and erosion. Flow Reduction Underdrain for wet sites

Outlet clean underdrain water separate from ditches! Flow Reduction Address off Right-of-way water VEGETATION (including bio-engineering)

• SLOWS AND USES WATER IN DITCHES

• SHADE & HABITAT ALONG STREAM

• NATURAL

• $$$$$$$$$$$$$$$$$$ VEGETATION VEGETATION Rip-rap -vs- vegetation

1/2 VEGETATION Rip-rap -vs- vegetation

2/2 ADDITIONAL ALTERNATIVES ADDITIONAL ALTERNATIVES

Inlet Protection ALTERNATIVESADDITIONAL ALTERNATIVES

Flared end section ADDITIONALPROPER ALTERNATIVES USE

Placed Native Stone ALTERNATIVESADDITIONAL ALTERNATIVES

Managing Ditch Flow ALTERNATIVESADDITIONAL ALTERNATIVES

Managing Ditch Flow ALTERNATIVESADDITIONAL ALTERNATIVES J-HOOK

BANKS ARE PROTECTED

1/2 Natural Stream Channel Design ADDITIONAL ALTERNATIVES

J-HOOK BANKS ARE PROTECTED

2/2 ALTERNATIVES TO RIP-RAP

1. Avoid Concentrating Drainage Raise Road, Underdrain, Eliminate Berm and/or Ditch 2. Divide Concentrated Flow to Encourage Infiltration Additional crosspipes and outlets

3. Use Alternative materials Native Stone, Vegetation, etc