PROJECT PREPARATION Surface Drainage Module - PowerPoint PPT Presentation

1 / 76
About This Presentation
Title:

PROJECT PREPARATION Surface Drainage Module

Description:

Objective of this topic is to educate those preparing projects on: ... Soil backfill/ compaction to resist bird-baths. Check Dams. Intended Uses. Recommended ... – PowerPoint PPT presentation

Number of Views:606
Avg rating:3.0/5.0
Slides: 77
Provided by: FSDefau8
Category:

less

Transcript and Presenter's Notes

Title: PROJECT PREPARATION Surface Drainage Module


1
PROJECT PREPARATIONSurface Drainage Module
  • Specifying Surface Drainage Structures to Solve
    Problem Areas on Trails

2
Objective
  • Objective of this topic is to educate those
    preparing projects on
  • The importance of managing water on or within the
    trail tread
  • Being able to identify problems
  • Prescribing efficient solutions

3
Fundamentals of Surface Subsurface Water Issues
  • Surface Water Issues
  • Sheet Runoff
  • Concentrated within Channels

4
Water Issues (cont.)
  • Soil Types
  • Litter

5
Standing water held in trail Causes accelerated
tread failure/erosion
6
Water retained on trail tends to widen trail and
promotes by-passes
7
Major tread erosion from no cross drainage near
a main water source like a stream crossing or
lake outlet
8
Unchecked Surface water
9
Failed waterbar with rutting from mountain bike
10
Trail widening due to persistent water
retention and mud
11
Surface Drainage Structures
  • Waterbars
  • Open Top Drains
  • Drain Dips
  • Culverts
  • Check dams
  • Outsloping
  • Ditches
  • Berms

12
WATERBARS
13
922-1 Rock Waterbar
  • Angle is critical
  • Spillways are critical on erosive soils
  • Keying into hillside
  • Burial depth important

14
922-2 Log Waterbar
  • Design basics
  • Material options

15
922-3 Belted Waterbar
  • Design basics
  • Material options

16
Rock and Log Waterbars
  • Intended Uses
  • Recommended
  • Stock
  • Hikers
  • Not Recommended
  • Motorized (use drain dips or belted)
  • Mountain Bikes (use drain dips)

17
Rock and Log Waterbars
  • Limitations
  • Rock Waterbars
  • Availability of adequate rock
  • Sandy soils
  • Log Waterbars
  • Availability of local native sources
  • Treated sensitivities within wilderness

18
Rock and Log Waterbars
  • Costs
  • Rock Waterbars
  • Availability of adequate rock
  • Could last forever
  • Log Waterbars
  • Availability of local native sources
  • Native lasts only 8-12 years, depending on
    species and local moisture
  • Treated could last 30 50 years
  • Maintenance

19
Log Waterbar new, good, rock anchors
20
Log Waterbar 2-track, well constructed, rebar
anchors
21
Log Waterbar Extra wide trail, appears to be
working
22
Log Waterbar Native-log w/bark, Wood stakes
23
Log Waterbar new installation, appears to be at
90 degrees
24
Log Waterbar trail around end of waterbar
25
Log Waterbar Sharp bend in trail, sometimes good
location
26
Log Waterbar outlet blocked by log
27
Log Waterbar waterbar too log, shotguned
28
Rock Waterbar good example
29
Rock Waterbar Good example
30
Rock Waterbar large single rock, need to
watch with stock,
31
Belted Waterbar during installation, no wood
frames
32
Belted Waterbar after installation
33
Belted Waterbar installed on ATV trail
34
DRAIN DIPS
35
912-4 Drain Dips
  • Design basics
  • For new construction

36
912-4 Drain Dips
  • Design basics
  • For reconstruction

37
Drain Dips
  • Intended Uses
  • Recommended
  • Stock
  • Hikers
  • Motorized (use drain dips or belted)
  • Mountain Bikes (use drain dips)

38
Drain Dips
  • Limitations
  • Difficult to install on reconstruction of steep
    grades

39
Drain Dips
  • Costs
  • Same as for tread construction
  • Lasts as long as the tread
  • Maintenance
  • Easy to maintain

40
Natural grade breaks
41
CULVERTS
42
921-1 Culvert w/ Headwalls
  • Plastic or metal, sensitive to where placed
  • Need to size to stream hydraulics
  • Size of cap rocks critical
  • Burial depth important
  • Fish Passage may be a requirement

43
921-2 Culvert w/o Headwalls
  • Stream needs to stabile without a lot of scour
    potential
  • Retainers critical to retain tread

44
921-3 Rock Culvert
  • Need to have adequate source of stone
  • Side rocks need to be buried to resist scour
  • Soil coverage with retainers

45
921-4c Box Culvert
  • Plastic or metal, sensitive to where placed
  • Need to size to stream hydraulics
  • Size of cap rocks critical
  • Burial depth important
  • Fish Passage may be a requirement

46
Culverts
  • Intended Uses
  • Recommended
  • Stock
  • Hikers
  • Motorized (use drain dips or belted)
  • Mountain Bikes (use drain dips)

47
Culverts
  • Limitations
  • Depth and Size
  • Plastic or Metal, advantages/disadvantages
  • for Setting and Transport
  • Plastic does not handle wildfire well

48
Culverts
  • Costs
  • Increase cost of metal culverts
  • Maintenance
  • Catch basin and outlet must be kept functional
  • Pipe must be kept cleaned out to prevent plugging

49
Culvert w/ Headwall Squashed metal pipe, with
rock retainers May be alittle small relative to
stream width
50
Culvert w/ Headwall round plastic pipe with log
retainers to contain tread materials
51
Culvert w/ Headwall Twin round pipes for added
capacity without height Need to ensure adequate
compaction between
52
Culvert Maintenance needed
53
Culvert Burial depth issue, Maintenance required
54
Log Culvert Good example, rustic, tough to get
capacity, tough to clean
55
Rock Culvert Tough to get capacity, but rustic
56
CHECK DAMS
57
915-2 Check Dams
  • Wide chose of materials
  • Width to trails critical
  • Pinning/burial important
  • Soil backfill/ compaction to resist bird-baths

58
Check Dams
  • Intended Uses
  • Recommended
  • Stock
  • Hikers
  • Not Recommended
  • Motorized (use drain dips or belted)
  • Mountain Bikes (use drain dips)

59
Check Dams
  • Limitations
  • Difficult to properly install
  • Require future maintenance and monitoring

60
Check Dams
  • Costs
  • Relatively inexpensive to install
  • Maintenance
  • Requires future maintenance and monitoring

61
Check Dams Used in series as part of old tread
restoration
62
Check Dams Series of rocks, might be narrow -
notice use outside of established tread
63
OUTSLOPING
64
Outsloping
  • Build in during construction, reconstruction, or
    maintenance
  • Preferred on trail classes 1-3
  • Harder to maintain on high-class, high-use trails
  • Use in combination with cross drains,
    particularly in high risk situations, such as
    below side channels

65
Outsloping
66
DITCHES
67
Ditches
  • Start with substantial size, allows to grow in
    and minimizes future maintainace
  • Control gradient
  • Provide adequate daylighting
  • Depth depends on local conditions

68
Ditches (cont)
  • Use to lower ground water or intercept overland
    flow
  • Commonly used in combination with other
    structures such as turnpike
  • Relieve water from ditch frequently
  • Averages 4 per lineal foot
  • Wide and deep ditches last much longer without
    maintenance

69
Side Ditches Side ditching to intercept ground
and surface waters
70
Leadoff Ditch Drains side ditch, clear well
away from trail to minimize maintenance
71
BERMS
72
Berms
  • Rarely constructed, develop over time due to
    tread erosion, movement
  • Remove when not near stream channel, at minimum,
    open frequent holes
  • When next to streams, leave berms until water
    from tread can be removed with filtration zone
  • Can tend to keep stock within tread and off
    outside edge

73
Berms Small berm developing on right, ok for now
74
Berms Large berm with substantial Vegetation on
right
75
Berm w/ Rock Barrier
76
End Surface Drainage
Write a Comment
User Comments (0)
About PowerShow.com