20120403200438_hobson-creek-restoration-project-phase3

              HOBSON CREEK CORRIDOR RESTORATION PROJECT, PHASE 3
TRIBUTARY 6 TO THE EAST BRANCH DUPAGE RIVER
Section 319 Project Report
Illinois EPA Agreement No. 3190511
Illinois Environmental Protection Agency
Bureau of Water
Watershed Management Section
September 2008
HOBSON CREEK COMMUNITY COUNCIL
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 2
HOBSON CREEK CORRIDOR RESTORATION PROJECT, PHASE 3
TRIBUTARY 6 TO THE EAST BRANCH DUPAGE RIVER
SECTION 319 FINAL REPORT
ILLINIOS EPA FAA # 3190511
SEPTEMBER 2008
Prepared For:
ILLINOIS ENVIRONMENTAL PROTECTION AGENCY
BUREAU OF WATER – WATERSHED MANAGEMENT SECTION
1021 NORTH GRAND AVENUE EAST
SPRINGFIELD, IL 62702
Prepared by:
LIVING WATERS CONSULTANTS, INC.
1 SOUTH 132 SUMMIT AVENUE, SUITE 304
OAKBROOK TERRACE, IL 60181
Ph: 630-261-1133 Fax: 630-261-1144
This report was prepared using United States Environmental Protection Agency funds under Section 319
of the Clean Water Act distributed through the Illinois Environmental Protection Agency. The findings
and recommendations contained herein are not necessarily those of the funding agencies.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 3
HOBSON CREEK CORRIDOR RESTORATION PROJECT, PHASE 3
TABLE OF CONTENTS
Report Section Page #
Summary 4
Introduction 4
Project Schedule 7
Project Description and Stabilization Techniques 7
Restoration of Riparian Corridor 7
Rock Vortex Weir Structures 8
A-Jacks and Vegetated Geogrid 8
Fiber Roll and Re-Shaped Slopes 9
Fiber Roll Terrace 9
Cobble Placement at Storm Pipe Outfalls 9
Native Plantings 10
Project Costs and Quantities 14
Operation and Maintenance Plan 16
Project Benefits 18
Photos Attachment 1
Project Articles Attachment 2
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 4
Summary:
The Hobson Creek Community Council completed the Hobson Creek Corridor Restoration Project,
Phase 3 in order to protect against severe streambank erosion, to provide nonpoint source
pollution control along Hobson Creek and to improve water quality of the downstream East
Branch DuPage River. Installed stream stabilization techniques have provided effective and
environmentally sound bank protection and channel stability for the Phase 3 reach. The Hobson
Creek Community Council will provide long-term maintenance for the project site. Public
involvement to date includes awareness of adjacent homeowners, and numerous trail and parkway
visitors near existing signage.
Introduction:
The Hobson Creek Corridor Restoration Project is located on common space owned by the
Hobson Creek Community Council in unincorporated Naperville, DuPage County, Illinois. Hobson
Creek has a 1.71 square mile watershed. The watershed is primarily comprised of single family
and multi-family residential areas. Hobson Creek has also been identified as Tributary #6 to
the East Branch DuPage River. The East Branch DuPage River is located approximately 1,100
linear feet downstream of the project site. The entire Hobson Creek Corridor has been divided
into 3 reaches for construction implementation purposes. Each phase of construction has
received Section 319 Clean Water Act grant funding obtained through the Illinois EPA and U.S.
EPA. The project phases are as follows:
Phase 1 – Upstream project boundary downstream to stream station 10+00 (Sta. 17+50 to 10+00)
Completed Spring 2004
Phase 2 – Stream station 10+00 downstream to Green Trails Drive (Sta. 10+00 to 3+50)
Completed Spring 2005
Phase 3 – Site 1: Mainstem Hobson Creek from Green Trails Drive to Seven Bridges Park (Sta.
2+75 to 0+00)
Site 2: Hobson Creek Inlet Channel (Sta. 2+75 to 0+00)
The Phase 3 project area is the subject of this Final Report. The entire Phase 3 area is located
within the Hobson Creek Subdivision, and is contained within common open space area owned by
the Hobson Creek Community Council (HCCC). The Phase 3 Hobson Creek Restoration consists
of two project locations. Site Location 1 is located along Hobson Creek at Green Trails Drive
immediately downstream of the Phase 2 site. The Hobson Creek project area is comprised of a
275 linear foot mainstem segment of Hobson Creek with a 0.1-acre degraded riparian corridor.
Site Location 2 is the Hobson Creek Inlet Channel Corridor Restoration. The Inlet Channel is
approximately 275 linear feet in length and is located south of Hobson Creek on the attached
exhibit. The Inlet Channel begins as the discharge of an 18-inch RCP storm pipe from the
single-family residential neighborhood (see photos). The sewer-shed area is several acres in
area. The Inlet Channel discharge flows into the 1-acre Hobson Creek Detention Pond. The
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 5
outflow from the detention basin discharges to Hobson Creek within the Phase 1 Project Area at
stream station 12+00. Restoration of the 0.27-acre vegetative corridor along the Inlet Channel
will be required to replace the Buckthorn (Rhamnus cathartica) infestations with deep-rooted
native plant species to provide improved bank stabilization.
Severe streambank erosion was due several factors. Most of the watershed was developed
prior to the enforcement of stormwater detention ordinances, resulting in the rapid discharge
of large volumes of urban runoff. A topographic survey was completed for the Hobson Creek
Phase 3 mainstem (Site 1) project area in 2003 and for the Inlet Channel (Site 2) in 2006. The
Hobson Creek mainstem reach slope is moderately steep for DuPage County, approximately
0.0051 ft/ft, or one foot of vertical fall every 195 linear feet of horizontal distance. The Inlet
Channel reach slope is 0.0016 ft/ft, or one foot of fall for every 63 feet. These are moderately
steep channel slopes for northeastern Illinois. The dominant soil type in the project area is
Ashkum silty clay loam (232). The streambank riparian corridor was also impacted by a dense
canopy of invasive shrubs including Buckthorn (Rhamnus cathartica) and Honeysuckle (Lonicera
tatarica). The highly eroded streambanks contained little to no ground-stabilizing vegetation.
This provided little functional benefit and contributed to site degradation. The mainstem
stream channel had incised approximately two feet into the landscape. Moreover, significant
channel widening had occurred. There is one location in the Phase 3 mainstem (Site 1) project
reach (Station 0+50) where severe streambank erosion caused stream channel migration to
within approximately 10 feet of a paved pedestrian walking / biking path used for access to
Seven Bridges Park in the Woodridge Park District. On the Inlet Channel (Site 2), large trees
had recently fallen into the eroding stream channel. The severe streambank erosion had
resulted in significant sediment delivery to the East Branch of the DuPage River. Moreover, the
streambank riparian corridor had become encroached with a dense canopy of invasive, exotic
shrubs including Buckthorn (Rhamnus cathartica). This has provided little functional benefit to
the site, and has contributed to site degradation as discussed below (under Proposed
Stabilization Plan). The Illinois EPA Load Reduction Spreadsheet was utilized to quantify the
significant sediment delivery to the East Branch of the DuPage River as described below under
Project Benefits.
A primary objective of the Hobson Creek Corridor Restoration Project was to improve the water
quality in the project area and to reduce the sediment loading caused by streambank erosion
into Hobson Creek and the East Branch DuPage River. This objective was accomplished by
extensive streambank stabilization, installation of channel grade control structures, removal of
invasive shrub species in the riparian area, and installation of native plantings along the
stabilized streambanks and within the riparian area.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 6
Project Location Map
Project Sites
#1
#2
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 7
Project Schedule
Table 1 below indicates the project schedule and completion requirements. Permits for the
Phase 3 Project Sites were submitted in fall 2006 but were not received until June 5, 2008. A
significant project delay occurred due to an apparent change in DuPage County permit review
process for Phase 3 which required a hydrologic and hydraulic model to ensure that the
proposed Phase 3 project did not contribute to impacts in the FEMA flood management areas.
Phase 3 project construction began June 17, 2008 and native planting installations (native shrub
live stakes and herbaceous plant plugs) were completed September, 2008.
Table 1: Project Schedule.
Hobson Creek Corridor Restoration Project, Phase 3.
IEPA FAA 3190511.
Action Item Start Date Completion Date
FAA 3190511 Award August 3, 2005 September 30, 2008
Design Engineering August 5, 2005 October 9, 2005
Permitting October 10, 2005 June 5, 2008
Bidding April 11, 2006 May 4, 2006
Construction Contract Award N/A Feb. 29, 2008
Riparian Invasive Species Removal June 17, 2008 July 1, 2008
Streambank Stabilization Construction July 1, 2008 August 22, 2008
Native Plantings August 22, 2008 September 25, 2008
Project Final Report September 29, 2008
Project Description and Stabilization Techniques
The Hobson Creek Corridor Restoration Project, Phase 3 stream stabilization design,
engineering, native planting selection, construction observation, and maintenance assistance has
been provided by Living Waters Consultants. Surveying was completed by Patrick Engineering,
Inc. and Thompson Surveying. McGinty Brothers provided construction services and was
contracted to provide a minimum of 3 years of site maintenance. The best management
practices described below were utilized to restore the riparian corridor and to stabilize the
streambanks of the Phase 3 project area.
Restoration of Riparian Corridor
Hobson Creek Corridor Restoration included vegetation management with replacement of 0.37
acres of dense stands on non-native and invasive shrubs and trees (such as Buckthorn) with 14
native tree-shrub clusters, along with native herbaceous species. The replacement of
undesirable vegetation with native species prevents loss of bank soils and promotes bank
stability. This will reduce non-point source pollutant loadings to the downstream East Branch
DuPage River. Replacement of invasive species with native tree and shrub clusters, grasses, and
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 8
forbs will also promote filtration and assimilation of nutrients as well as contaminated runoff
that can be discharged from surrounding upland areas. Aquatic habitat along the Hobson Creek
riparian corridor will be enhanced and diversified.
Table 2: Streambank Stabilization Practices.
Hobson Creek Mainstem (Site 1)
Left Bank Right Bank Total
Stabilization Practice (LF) (RF) (LF)
1 Row A-Jacks / 1 Row Geogrid / Reshape 90 90
3 Row A-Jacks / Cobble Layer / 1 Row Permanent Geogrid / Reshape 50 50
2 Row A-Jacks / Reshape 30 30
1 Row A-Jacks / Re-Shape 10 10
Rock Vortex Weir 8 8 16
Cobble Toe / Reshape 30 30
Cobble Replacement at Storm Pipe Outfall 10 10
Cobble Replacement at Detention Basin Outlet 30 30 60
Fiber Roll / Reshape 20 20
Total 188 128 316
Inlet Channel (Site 2)
Left Bank Right Bank Total
Stabilization Practice (LF) (RF) (LF)
1 Row A-Jacks / Reshape / Fiber Roll Terrace 60 60
1 Row A-Jacks / Reshape 70 20 90
Rock Vortex Weir 16 16 32
Cobble Replacement at Storm Pipe Outfall 30 30 60
Cobble Replacement At Stream Bottom (downstream area) 50 50 100
Fiber Roll Toe / Reshape / Fiber Roll Terrace 20 20
Fiber Roll Toe / Reshape 60 60 120
Fiber Roll Terrace 20 20
Native Plant Plugs (2/LF) 25 15 40
Total 271 271 542
Rock Vortex Weir Structures
Channel downcutting has been controlled with the installation of three (3) rock vortex weir
grade control structures. The constructed weir structures not only control and prevent further
channel downcutting but also dissipate excess stream energy and reduce extremely high erosive
forces against the streambanks. Materials utilized ranged from 0.5-inch subsurface gravel to
18-inch surface boulders. The rock weir structures also diversify and improve in-stream
habitat, diversify stream substrate materials, and enhance aesthetics.
A-Jacks and Vegetated Geogrid or Re-Shape Slope
Streambank stabilization was a critical BMP to prevent additional soil pollutant transport
throughout Hobson Creek and the downstream East Branch DuPage River. In the more severely
eroded areas, the streambanks were graded to a flatter slope (excess cut removed), seeded and
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 9
planted using native vegetation (described below), stabilized with vegetated geogrid (NAG C350
or Bio-D Block), with toe of slope protection using 1 row or 3 rows of A-jacks. The permanent
A-Jacks structures have a high energy-dissipation capability. The vegetated geogrid provided
erosion control along tall slopes as steep as 2.5:1 (H:V). These techniques were suited for areas
that could be stabilized with vegetation alone, such as areas with high flow velocities along
erodible soils, and where high bank shear stresses and sharp meander bends occur.
Approximately 50 linear feet of 3-rows a-jacks were installed, 30 linear feet of two-rows a-jacks,
as well as 100 linear feet of 1-row a-jacks on the Mainstem (Site 1). Approximately 150
linear feet of 1-row a-jacks were installed at the Inlet Channel (Site 2).
Fiber Roll and Re-Shaped Slopes
Streambanks with moderate erosion along the toe of slope were lightly graded back, on a cut-and-
fill balance, seeded and planted with native plant vegetation, covered with an erosion control
blanket, with toe (base) stabilization using coconut (coir) fiber roll. Areas exhibiting only minor
erosion were stabilized by re-shaping bank slopes, seeding and planting with native vegetation,
and installing erosion control blanket. Plant communities were improved by removing the non-native
/ invasive vegetation, as well as introducing rooted plant materials. Approximately 20
linear feet of fiber roll were installed with re-shaped slopes above the fiber roll on the
Mainstem, while 140 linear feet were installed on the Inlet Channel.
Fiber Roll Terrace
Streambanks with moderate erosion along the toe of slope along with moderately steep or
eroding overbank slopes were also stabilized by lightly grading back the overbank slope, on a
cut-and-fill balance, seeded and planted with native plant vegetation, along with a coconut (coir)
fiber roll installed along the middle of the slope, parallel to the bank. The fiber roll terrace will
serve to reinforce steep slope areas to prevent bank sliding or other failure due to steep bank
slopes and / or tall bank heights. Approximately 100 linear feet of fiber roll terrace were
installed on the Inlet Channel.
Cobble Placement At Streambank, Storm Pipe Outfalls, Tree Roots, and Channel Bottom
Cobble toe was installed over 20 linear feet on the mainstem along the right bank toe of slope at
Station 0+25. Three existing storm pipe outfalls were also stabilized by re-placing rock that
had previously been removed by the erosive force of the flowing stream. The Mainstem (Site 1)
left bank contained a storm pipe outfall that was stabilized by installing a rock toe near left
bank Station 2+00. Cobble rock was also placed along 10 linear feet of exposed tree roots at
the right bank near Station 2+00. The Inlet Channel (Site 2) had two locations where storm
pipe outfalls were stabilized by re-placing cobble rock (Stn. 2+75 and Stn. 0+00). The latter
location included replacing approximately 30 linear feet of rock along an outfall path between
the storm sewer outfall and the detention basin. The total length of outfall channel banks
protected by rock placement was 60 linear feet. Other maintenance activities included
replacing approximately 50 linear feet of cobble rock along the stream bottom (extending from
the left bank to the right bank of the channel) at the downstream end of the Inlet Channel
extending to the existing detention basin, between Station 0+50 and 0+00. The total length of
both streambanks protected by rock placement at the stream bottom between Station 0+50 and
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 10
0+00 was 100 linear feet. Cobble rock was also placed along 30 linear feet of the channel
bottom of a detention basin flowpath at Site 1.
Native Plantings
Proper selection and installation of native plantings and seed is instrumental to project success.
Native seed and plantings were installed along all stabilized streambank areas. Effective native
plant installations improve long-term streambank stabilization, pollutant filtration, wildlife
habitat, dissipation flow energy, and improvement of site aesthetic values. Toe-of-slope (Type
1) native seed and plug lists, and mid-slope to upper slope native seed (Type 2) plug lists are
provided in Tables 3 and 4 below. Native shrub live stakes (cut live stems) were replaced with
potted herbaceous native plant plugs since the installation had to occur between June and
September, 2008. (This construction schedule likely would not have allowed for substantial
survival of shrub live stakes which are in general most successfully installed in the dormant
growing season.) Approximately 40 linear feet of stream channel was stabilized using native
plantings alone without other streambank stabilization treatments. Also, as described above
under Restoration of Riparian Corridor, fourteen (14) native trees and 42 native potted shrubs
were installed as tree-shrub clusters throughout each riparian area. Fifty-eight (58) native
potted shrubs were also installed, primarily along the Inlet Channel (Site 1). The ball-and-burlap
tree and shrub species used for the tree-shrub clusters are described in Table 6.
Table 3. Native Herbaceous Plant Plugs Species List.
Scientific Name Common Name Percent of Total
TYPE 1 NATIVE PLANT PLUGS
ACORUS CALAMUS SWEET FLAG 10%
ANDROPOGON GERARDII BIG BLUESTEM 3%
ANDROPOGON SCOPARIUS LITTLE BLUESTEM 8%
ASCLEPIAS INCARNATA SWAMP MILKWEED 3%
CAREX COMOSA BRISTLY SEDGE 7%
CAREX TRIBULOIDES POINTED OVAL SEDGE 5%
CAREX VULPINOIDEA FOX SEDGE 7%
ELYMUS CANADENSIS PRAIRIE WILD RYE 5%
ELYMUS VIRGINICUS VIRGINIA WILD RYE 7%
IRIS VIRGINICA BLUE FLAG IRIS 8%
JUNCUS TORREYI TORREY'S RUSH 5%
PANICUM VIRGATUM SWITCH GRASS 14%
SCIRPUS CYPERINUS WOOL GRASS 3%
SPARTINA PECTINATA PRAIRIE CORD GRASS 10%
VERBENA HASTATA BLUE VERVAIN 5%
100%
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 11
TYPE 2 NATIVE PLANT PLUGS
ALLIUM CERNUUM NODDING WILD ONION 3%
ANDROPOGON SCOPARIUS LITTLE BLUESTEM 3%
AQUILEGIA CANADENSIS COLUMBINE 3%
ASTER LATERIFLORUS SIDE-FLOWERING ASTER 3%
ASTER NOVAE-ANGLIA NEW ENGLAND ASTER 3%
CAREX JAMESII GRASS SEDGE 3%
DIARRHENA AMERICANA BEAK GRASS 4%
ECHINACEA PURPUREA PURPLE CONEFLOWER 9%
ELYMUS CANADENSIS WILD CANADA RYE 6%
ELYMUS VIRGINICA VIRGINIA WILD RYE 7%
EUPATORIUM PERFOLIATUM BONESET 8%
GERANIUM MACULATUM WILD GERANIUM 3%
HELIANTHUS GROSSESERATUS SAWTOOTH SUNFLOWER 3%
LOBELIA CARDINALIS CARDINAL FLOWER 3%
LOBEILIA SIPHILITICA GREAT BLUE LOBELIA 3%
MONARDA FISTULOSA BERGAMONT 5%
PANICUM VIRGATUM SWITCH GRASS 9%
PARTHENIUM INTEGRIFOLIUM QUININE 3%
PENSTEMON CALYCOSUS SMOOTH PENSTEMON 3%
SOLIDAGO OHIENSIS OHIO GOLDENROD 3%
SOLIDAGO PATULA SWAMP GOLDENROD 3%
SOLIDAGO SPECIOSA SHOWY GOLDENROD 3%
TRADESCANTIA OHIENSIS SPIDERWORT 3%
TRILLIUM ERECTUM TRILLIUM 3%
100%
Table 4. Native Plant Seed List.
Scientific Name Common Name Percent of Total
TYPE 1 NATIVE PLANT SEED (35 LB/ACRE)
ASTER LATERIFOLIUS SIDE-FLOWERING ASTER 5%
ASTER NOVAE-ANGLIAE NEW ENGLAND ASTER 5%
ASTER SIMPLEX MARSH ASTER 3%
ANDROPOGON SCOPARIUS LITTLE BLUESTEM 5%
CAREX COMOSA BRISTLY SEDGE 6%
CAREX SPARGANOIDES BURRED SEDGE 6%
CAREX STIPATA COMMON FOX SEDGE 6%
CAREX TRIBULOIDES POINTED OVAL SEDGE 3%
CAREX VULPINOIDEA FOX GRASS 6%
ELYMUS CANADENSIS CANADA WILD RYE 7%
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 12
ELYMUS VIRGINICUS VIRGINIA WILD RYE 6%
GENTIANA ANDREWSII BOTTLE GENTIAN 3%
GILARDIA PULCHELLA INDIAN BLANKET 3%
JUNCUS TORREYI TORREY'S RUSH 3%
MONARDA FISTULOSA BERGAMONT 5%
PANICUM VIRGATUM SWITCH GRASS 9%
PHLOX DIVARTICA BLUE PHLOX 2%
RUDBECKIA HIRTA BLACK-EYED SUSAN 5%
SOLIDAGO GIGANTEA LATE GOLDENROD 3%
SORGHASTRUM NUTANS INDIAN GRASS 3%
SPARTINA PECTINATA PRAIRIE CORD GRASS 6%
100%
TYPE 2 NATIVE PLANT SEED (35 LB/ACRE)
ALLIUM CERNUUM NODDING WILD ONION 3%
ANDROPOGON SCOPARIUS LITTLE BLUESTEM 6%
AQUILEGIA CANADENSIS COLUMBINE 3%
ASTER CORDIFOLIUS HEART-LEAVED BLUE ASTER 3%
ASTER LAEVIS SMOOTH ASTER 3%
ASTER NOVAE-ANGLIAE NEW ENGLAND ASTER 3%
CAREX CRINITA FRINGED SEDGE 5%
CAREX NORMALIS SPREADING OVAL SEDGE 4%
CAREX SPARGANOIDES BURRED SEDGE 4%
CASSIA FASCICULATA PARTRIDGE PEA 2%
DIARRHENA AMERICANA BEAK GRASS 4%
ECHINACEA PURPUREA PURPLE CONEFLOWER 5%
ELYMUS CANADENSIS WILD CANADA RYE 5%
ELYMUS VIRGINICUS VIRGINIA WILD RYE 6%
EUPATORIUM PERFOLIATUM BONESET 4%
GLYCERIA STRIATA FOWL MANNA GRASS 4%
MONARDA FISTULOSA BERGAMONT 3%
PANICUM VIRGATUM SWITCH GRASS 7%
RATIBIDA PINNATA YELLOW CONEFLOWER 5%
RUDBECKIA HIRTA BLACK-EYED SUSAN 8%
SOLIDAGO GIGANTEA LATE GOLDENROD 5%
SOLIDAGO SPECIOSIA SHOWY GOLDENROD 5%
VERONIA FASCICULATE IRONWEED 3%
100%
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 13
Table 5. Native Tree-Shrub Clusters.
Scientific Name Common Name Percent of Total
Trees
Carya ovata Shagbark Hickory 10%
Juglans nigra Black Walnut 20%
Platanus occidentalis American Sycamore 25%
Quercus bicolor Swamp White Oak 20%
Quercus macrocarpa Burr Oak 25%
100%
Shrubs
Cephalanthus occidentalis Button Bush 25%
Cornus stolonifera Red-Osier Dogwood 15%
Sambucus canadensis Elderberry 25%
Viburnum dentatum Arrowwood Viburnum 20%
Viburnum lentago Nannyberry Viburnum 15%
100%
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 14
Project Costs and Quantities
A summary of quantities and costs are listed below.
Table 6: Summary of Quantities.
BASE BID SCHEDULE OF QUANTITIES AND PRICES
BASE
BID
Item No. Stream Restoration Practice Quantity Units Unit Cost Extended Cost
1 Nuisance Shrub Removal 0.37 ACRES $6,500.00 $2,405.00
2 Tree Removal 4" to 12" Diameter 6 EA $350.00 $2,100.00
3 Tree Trimming / Limb Removal 10 EA $55.00 $550.00
4 Rock Vortex Weirs 3 EA $1,800.00 $5,400.00
5 Fiber Roll 150 LF $40.00 $6,000.00
6 1-Row A-Jacks 270 LF $57.50 $15,525.00
7 3-Row A-Jacks 30 LF $130.00 $3,900.00
8
3-Row A-Jacks / Cobble Layer / Grout
Surface Cobble 50 LF $160.00 $8,000.00
9 Vegetated Geogrid (Bio-D Block) 200 LF $8.00 $1,600.00
10 Fiber Roll Terrace (mid-slope) 110 LF $40.00 $4,400.00
11
Re-Shaped Streambank Earthwork / Erosion
Blanket 360 LF $7.00 $2,520.00
12
Round Cobble Installation Along Storm Pipe
Outlets 11 CY $550.00 $6,050.00
13 Native Tree / Shrub Clusters 14 EA $200.00 $2,800.00
14 Native Shrub Live Stakes (2 / LF) 90 LF $6.00 $540.00
15 Native Potted Plugs (2 / LF) 80 LF $9.00 $720.00
16 Native Potted Shrubs 20 EA $50.00 $1,000.00
17 Boulder Placement 12 EA $175.00 $2,100.00
18
Trench Downspouts to Stream (Avg. 10 ft.
each) 2 EA $880.00 $1,760.00
19 Construction fencing 1,000 LF $3.25 $3,250.00
20 Erosion Control 1 LS $1,750.00 $1,750.00
21 Site Cleanup and Restoration 1 LS $2,800.00 $2,800.00
22 Native Plant Maintenance 3.0 Year $3,300.00 $9,900.00
23
Relocate Existing Project Sign and Install 2
Decals 2 LS $600.00 $1,200.00
24 Repair Woodcrest Lane Storm Sewer Inlet 1 LS $4,000.00 $4,000.00
Construction
Total - Base
Bid $90,270.00
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 15
BID EXTRAS
Item
No. Stream Restoration Practice Quantity Units Unit Cost Extended Cost
101 Bury Drain Tiles 2 HR $50.00 $100.00
102 Clear Walking Path at Top of Bank 3 HR $50.00 $150.00
103 Cut Tree 2 HR $50.00 $100.00
104 Grade Swale for Drain Tile 3 HR $50.00 $150.00
105 Earthwork at Top of Bank 6 HR $50.00 $300.00
106 Extra Construction Fence 470 LF $3.25 $1,527.50
107 10 LF Fiber Roll 10 LF $40.00 $400.00
108
Replace Rock at End of Inlet Channel, Site 2 (50
LF) 1 LS $3,300.00 $3,300.00
109
Replace Rock in Detention Basin Outlet Channel ,
Site 1 (30 LF) 1 LS $2,800.00 $2,800.00
110
Replace Rock at Storm Outfall Pipe , Site 2
(30 LF) 1 LS $1,700.00 $1,700.00
111
Added Two Red Viburnum 9-24-08 (1 near
sledding sign, 2 EA $175.00 $350.00
112 Shrubs - 3 Gallon Size 2 EA $50.00 $100.00
Shrubs - 5 ft Size
113 Viburnum lentago (5 ft tall) 6 EA $175.00 $1,050.00
114 Sambucus canadensis (4.5 ft / largest size) 12 EA $125.00 $1,500.00
115 Shrubs - 3 Gallon Size 8 EA $50 $400.00
116 Install Shrubs - 3 Gallon Size 30 EA $50 $1,500.00
Native Plant Plugs (2-in potted plugs)
117 Canada Wild Rye 250 EA $4.50 $1,125.00
118 Virginia Wild Rye 250 EA $4.50 $1,125.00
119 Columbine 225 EA $4.50 $1,012.50
120 Prairie Seed 1 LS $8,520.00 $8,520.00
Construction
Total - Bid
Alternates $27,210.00
Total Phase 3 Contractor Bid Costs: $117,480.00
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 16
Table 7: Project Cost Summary.
Hobson Creek Corridor Restoration Project, Phase 3.
IEPA FAA 3190511.
Project Cost Summary Total Cost Local Match Grant Assistance
to Date Share Amount
Clerical $0.00 $0.00 $0.00
Supervisor $0.00 $0.00 $0.00
DIRECT LABOR $0.00 $0.00 $0.00
Fringe Benefits $0.00 $0.00 $0.00
Overhead Costs $0.00 $0.00 $0.00
INDIRECT COSTS $0.00 $0.00 $0.00
EQUIPMENT, MATERIALS, SUPPLIES $0.00 $0.00 $0.00
Engineering $64,016.92 $25,606.77 $38,410.15
Surveyor / Surveying $10,928.55 $4,371.42 $6,557.13
Streambank Stabilization $105,380.00 $42,152.00 $63,228.00
Legal Expenses $5,340.00 $2,136.00 $3,204.00
Misc. Materials $214.06 $85.62 $128.44
SUBCONTRACTS $185,879.53 $74,351.81 $111,527.72
Totals $185,879.53 $74,351.81 $111,527.72
IEPA Grant Award: $116,986.00
Balance of Award: $5,458.28
Operation and Maintenance Plan
Maintenance of native plantings along the stabilized streambanks and within the riparian
corridor is critical to project success. The Hobson Creek Community Council will take
responsibility for the EPA Section 319 grant 10-year Operations & Maintenance agreement for
streambank bioengineering protection measures and plant maintenance. The following are
provisions for this Agreement.
Bioengineering Materials Inspections
Bioengineering materials inspections for the constructed streambank stabilization area will
occur at least two times per year according to the attached schedule in Table 8. Repairs will be
made as necessary, as determined by the Owner and their designated Representative.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 17
1. A-Jacks: Inspections will occur for dislodgement or relocation of A-Jacks components if any,
broken pieces, or other indications of potential stabilization concerns.
2. Fiber Roll Toe and Fiber Roll Terrace: Inspections will occur for the staking, undercutting,
cord fasteners, and integrity of the Fiber Roll.
3. Rock Vortex weirs: Some rock displacement at the vortex weir is expected, but significant
relocation of larger rock materials is not desirable. Major relocation of rock will be
inspected and noted.
4. Re-Shaped Slopes and Vegetated Geogrid: The performance of the re-shaped slopes and
vegetated geogrid to stabilize the site slopes will be inspected. Growth of vegetation and
locations requiring additional planting will be inspected. Eventually, the vegetated geogrid will
biodegrade presumably within a few years. The capability of plantings to stabilize the
resulting angle of repose will be noted.
Native Plant Maintenance
Conditions will be monitored and maintenance will be performed as described in the attached
schedule. Native plant maintenance will occur using spot herbicide applications, hand removal of
nuisance weeds, and related activities performed at least three times per year per the attached
schedule. Tree / shrub clusters which contain dead trees will be replaced according to the 3-
year Vegetative Performance Standards in the Specifications plan sheet. Non-native species
will be removed from the streambank stabilization area.
Maintenance Costs
The annual site maintenance budget will be $5,000 annually, primarily to control re-introduced
invasive species such as Buckthorn (Rhamnus cathartica), and Tartarian Honeysuckle (Lonicera
tatarica) from taking over the newly establishing native plants. Expenditures may be higher
expenditures during the first three years for native plant maintenance and nuisance weed
control as the native plantings become established. Costs for Operations and Maintenance shall
be paid by the Owner, the Hobson Creek Community Council.
Table 8. Site Maintenance Schedule.
Post-Construction through 2018
Activity late March mid-May mid-June mid-July mid-August
Mow and/or Cut Natives X
Spot Herbicide / Remove Weeds X X X
Bioengineering Materials Inspection X X
Responsibilities
The Hobson Creek Community Council Board and their designated Representative shall be
responsible for project site maintenance. Participating parties will include the Owner’s
Representative, professional Contractor services support, or possibly volunteers of the Hobson
Creek Community.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 18
Project Benefits
Water Quality
The Phase 3 substantial completion of streambank stabilization was completed by August 22,
2008. Final planting installations were completed by September 25, 2008. Rapid establishment
of temporary cover crop following slope stabilization occurred in early to mid-August with
substantial rainfall events. Subsequent observations of streambank stabilization occurred
following recent extremely intense regional rainfalls September 12-14, 2008. The banks
remained protected and erosion was greatly reduced. Between mid-August and mid-September,
several site watering applications were performed by the Contractor which helped to maintain
vegetative growth. Selected vegetation replacement of invasive trees and shrubs with native
species in the 0.37-acre riparian area will also substantially reduce the loss of bank soils and
promote bank soil stability. Native riparian plantings will reduce sheet erosion within the flood
zone. Rock vortex weirs will prevent channel downcutting which in the past caused site
degradation. These measures will significantly reduce non-point source pollutant loadings to the
downstream East Branch DuPage River. Based on site observations, there is minimal sediment
delivered to the stream from the restoration site.
The Illinois EPA Load Reduction Spreadsheet was used to calculate pollutant loading rates from
the project site. Input data included a combined streambank (left and right bank) length of 858
linear feet (see Table 2). For the Mainstem (Site 1), severe erosion included 200 linear feet of
streambank with a height of 5 feet and an erosion rate of 0.55 ft/yr. Moderate erosion
included 46 linear feet of streambank with a height of 3.5 feet and an erosion rate of 0.35
ft/yr. Low erosion included 70 linear feet storm pipe outfall and detention basin flowpath
erosion with an estimated erosion rate of 0.2 ft/yr. For the Inlet Channel (Site 2), severe
erosion included 262 linear feet of streambank with a height of 5 feet and an erosion rate of
0.4 ft/yr. Moderate erosion included 180 linear feet of streambank with a height of 3.5 feet
and an erosion rate of 0.4 ft/yr. Low erosion included 100 linear feet of Inlet Channel bottom
erosion with an estimated erosion rate of 0.2 ft/yr. Based on these assumptions, Site 1 and
Site 2 had previously contributed approximately 53 tons of sediment, 53 pounds of phosphorus,
and 108 pounds of nitrogen annually to Tributary # 6. These estimates do not include historic
sediment loss due to severe channel downcutting which has also occurred at this site. Due to
stream stabilization, these pollutant loading rates to Hobson Creek have been dramatically
reduced at the project site.
Habitat and Riparian Function
• Selected vegetation replacement of non-native species with native trees and shrub clusters,
grasses, and forbs will protect and diversity wildlife habitat corridor along Hobson Creek, as
well as diversity the native plant understory which is an indicator of a healthy ecosystem.
The proposed plant species will also increase the diversity of foraging opportunities for
wildlife.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 19
• Selected vegetation replacement will allow more desirable and beneficial species to flourish.
There were numerous impacts to ecological integrity caused by the previously existing
invasive plant species in the riparian zone. Dense stands of invasive shrubs such as common
buckthorn and Tartarian honeysuckle previously shaded and out-competed growth of
seedlings of bur oak (Quercus macrocarpa) and black walnut (Juglans nigra) which occur in
limited number in the riparian area. Indeed, few seedlings of these desirable tree species
were previously observed in the existing riparian area. Riparian restoration will increase
sunlight penetration and increase the density of desirable tree and shrub species.
• The proposed riparian planting restoration will enhance the function of interception of
rainfall. Deep-rooted trees and plants have increased absorption properties over the
existing riparian species.
• The proposed density of trees, shrubs, forbs and grasses will enhance pollutant filtration
and assimilation of nutrients as well as contaminated runoff discharged from surrounding
upland areas, or through the project site. Native groundcover such as grasses and forbs are
particularly efficient at trapping sediment in the uptake of phosphorus and nitrogen
nutrients which otherwise cause pollution within the waterway. The proposed planting plan
will significantly increase the abundance of groundcover species. Deep-rooted trees will
increase the uptake of nitrogen from shallow groundwater, improving water quality of the
stream.
• The proposed planting plan will help restore in-stream vegetative cover by encouraging
partial sunlight penetration into the water column to enhance growth of shoreline forbs and
grasses, as well as potentially allowing in-stream aquatic macrophytes. This will enhance the
function of in-stream habitat conditions.
Public Outreach / Education
Project Signage (per project plans) placed at strategic locations along Green Trails Drive near
Seven Bridges Park and at Spyglass Court are being utilized to notify motorists, pedestrians,
and visitors regarding the project, funding sources, and proposed improvements and activities.
The Mainstem project site # 1 adjoins a walking trail and outdoor athletic facilities at Seven
Bridges Park owned by the Woodridge Park District that likely receives thousands of visitors
annually. This park is located immediately downstream of Green Trails Drive. Many residents
and park visitors use trails and sidewalks along the Hobson Creek stream corridor which will
further enhance community educational outreach from the project site.
The Hobson Creek Community Council (HCCC) Board and members have been active over the last
several years in acquiring Phase 1, 2 and 3 Section 319 Clean Water Act grant funding through
the Illinois EPA and U.S. EPA, acquiring DuPage County Water Quality Improvement Program
funding, completing final engineering design, obtaining regulatory permit approvals for the Phase
1, 2 and 3 project areas, educating homeowners, acquiring landowner signoffs for the proposed
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 20
work in the common area, setting aside matching funds to complete portions of this project,
contracting with stream consultants, and other activities. Over 20 landowners along the project
site have been personally contacted by HCCC regarding the Phase 3 project and the entire
community has been notified regarding the work. Additional HCCC education includes Board
meetings, and quarterly newsletter updates. According to Mr. Bob Longacre of HCCC, in part as
a result of these efforts and a successful project, the residents of HCCC have been pleased
with the project results to date.
In the future, it is likely that the project sites will be used for site tours and workshops. For
example, in April 2006 the Phase 3 site was the subject of a field laboratory study for a
workshop presented by Ted Gray on Stream Restoration hosted at Illinois Institute of
Technology.
In the past, various newsletter, newspaper and periodical articles have been published regarding
the Hobson Creek Corridor Restoration Project Phases 1 and 2. Known information is as follows:
1) The Conservation Foundation newsletter Watershed Currents published a project article
in 2003, Vol. 2, Issue 2.
2) An article titled “Homeowners Work to Restore Creek” was published in The Naperville
Sun in mid-November, 2003. A letter to the editor of the Naperville Sun was published
in response to the newspaper article was submitted by the Commissioner of the Forest
Preserve District of DuPage County, entitled “Hobson Creek Restoration Lifts Quality of
Life.”
3) One pre-construction newspaper article was published in the Daily Herald, Section 1.
This newspaper article was entitled “Your Actions May Be Key to Water Quality, County
Says.”
4) One professional publicist published three professional journal articles featuring the
Hobson Creek Corridor Restoration Project.
a. An article entitled “Hobson Creek Restoration Project” was published in the
November / December 2004 Land & Water Magazine by Greg Northcutt including
interviews with Ted Gray.
b. An article entitled “Stable Streams” was published by Mr. Northcutt in December
2004 Civil Engineering News Magazine. November 2004.
c. An article titled “Stabilizing an Urban Streambank” was published by Mr.
Northcutt in the November, 2004 Landscape Architect and Specifier News.
5) Rolanka, manufacturer of Bio-D Block, has includes photos of the Hobson Creek
Restoration Project in national advertising materials.
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 21
ATTACHMENT 1: PROJECT PHOTOS
Phase 3 Hobson Creek Corridor Restoration Project Section 319 Final Report 22
ATTACHMENT 2: PROJECT ARTICLES