OPTION RO 7/21/08

OPTIONCLIENT Study Number Date Item No. City of Cedar Rapids Sasaki Associates Inc. 21493.02 9/10/08

Structural S9A Study

Title: Cedar Rapids River Corridor Redevelopment Flood Control Study

TITLE: Increase Cedar River Channel Cross Section by Dredging

DESCRIPTION:

Dredge Cedar River channel to provide an increased section to allow a higher flow rate. Based on dredging the river from the Five in One Dam (cross section T) to the south side of the landfill (cross section F). The typical cross section uses a minimum bottom width of 300 feet sloping from an invert elevation of 699.0 feet to 692.0 feet. Approximately 183,000 cubic yards of material removed from the channel, which includes rock excavation.

ADVANTAGES: Increased flow would reduce flood crest in Cedar Rapids.

DISADVANTAGES: Dredging likely to need permitting from several agencies. Spoil may include hazardous wastes (may contain phosphates, high pesticide levels and other farm runoff chemicals) which will need remediation or special waste disposal. Only small dredges can be used in river due to the available water depths (versus large dredges in Mississippi) which will cause high costs. High cost to remove/transport dredge material out of river floodway and floodplain. Short term option unless continuing maintenance dredging is performed. Although crest is reduced in Cedar Rapids, crests remain the same downstream.

Potential Reduction in 100-year Flood Crest: 0 ft to 0.4 ft. Potential Reduction in 500-year Flood Crest: 0 ft to 0.3 ft. Potential Reduction in 2008 Flood Crest: 0 ft to 0.2 ft. Likely Timeline Before Benefits Occur: 10 to 20 years ROM Cost Estimate: $26,000,000

COST DEVELOPMENTDate Item

9/9/2008

StudyTitle

Quantity Unit Labor andMaterials

Total

24,540 CY $38 $932,520

158,209 CY $114 $18,035,826

24,540 CY $38 $932,520

S9ACedar Rapids River Corridor Redevelopment Flood Control Study

Item

Project Length (15,730 ft/3 +/- miles)

Wet

Rock

Disposal

CLIENT Study NumberCity of Cedar Rapids Sasaki Associates Inc. 21493.02

Excavation (182,749 CY)

Dredging

158,209 CY $38 $6,011,942

1 LS $350,000 $350,000

$26,262,808

Use $26,000,000

Permitting

Total

Rock

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S

T

I

R

N

L

M

O

P

Q

J

K

F

H

G

0 1,500 3,000 4,500750Feet

City of Cedar RapidsS9A - Increase Cedar River Channel

Cross Section by Dredging

LegendCross Section LineFlood Control Option

OPTION RO 7/21/08

OPTIONCLIENT Study Number Date Item No. City of Cedar Rapids Sasaki Associates Inc. 21493.02 9/10/08

Structural S9B Study

Title: Cedar Rapids River Corridor Redevelopment Flood Control Study

TITLE: Increase Cedar River Channel Cross Section by Widening Channel

DESCRIPTION:

Dredge/widen Cedar River channel to provide an increased cross section area to allow a higher flow rate. Based on widening the river channel from the Five in One Dam (cross section T) to the south side of the landfill (cross section F). The typical cross section uses a minimum bottom width of 700 feet sloping from an invert elevation of 699.0 feet to 692.0 feet. Approximately 1,644,000 cubic yards of material removed from the channel, which includes rock excavation and 1,150,000 cubic yards of material removed form the banks. See figure for Option S9A.

ADVANTAGES: Increased cross section area to convey flow would reduce flood crest in Cedar Rapids.

DISADVANTAGES: Dredging/excavation likely to need permitting from several agencies. Spoil may include hazardous wastes (may contain phosphates and other farm runoff chemicals) which will need remediation or special waste disposal. High cost to remove/transport dredge material out of river floodway and floodplain. Short term option unless continuing maintenance dredging is performed. Although crest is reduced in Cedar Rapids, crests remain the same downstream.

Potential Reduction in 100-year Flood Crest: 0 ft to 3.8 ft. Potential Reduction in 500-year Flood Crest: 0 ft to 3.3 ft. Potential Reduction in 2008 Flood Crest: 0 ft to 3.2 ft. Likely Timeline Before Benefits Occur: 10 to 20 years ROM Cost Estimate: $333,000,000

COST DEVELOPMENTDate Item

9/9/2008

StudyTitle

Quantity Unit Labor andMaterials

Total

652,463 CY $19 $12,396,797

992,665 CY $38 $37,721,270

1,148,926 CY $114 $130,977,564

Excavation

Earth - Wet

Rock

Study NumberCity of Cedar Rapids Sasaki Associates Inc. 21493.02

CLIENT

Item

S9BCedar Rapids River Corridor Redevelopment Flood Control Study

Side Embankment

Dredging

Project Length - (15,730 ft/3 Miles)

652,463 CY $38 $24,793,594

992,665 CY $38 $37,721,270

1,148,926 CY $38 $43,659,188

50 AC $17,267 $863,350

3 EA $14,232 $42,696

8 EA $189,750 $1,518,000

3 EA $1,900,000 $5,700,000

3 Miles $3,795,000 $11,385,000

Structure Removal

Private

Infrastructure

Commercial

Industrial

Utilities

Clearing & Grubbing

Rock

Earth

Dry

Wet

Disposal

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COST DEVELOPMENTDate Item

9/9/2008

StudyTitle

Quantity Unit Labor andMaterials

Total

Study NumberCity of Cedar Rapids Sasaki Associates Inc. 21493.02

CLIENT

Item

S9BCedar Rapids River Corridor Redevelopment Flood Control Study

2 Miles $2,846,250 $5,692,500

3 EA $5,692,500 $17,077,500

1 EA $2,846,250 $2,846,250

1 LS $500,000 $500,000

Highway

Railway

Permitting

Bridges

Roads

$332,894,979

Use $333,000,000

Total

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