Construction and Maintenance Costs

The Integrated stormwater management section outlines a cost estimation method which site planners could use to compare the relative construction and maintenance costs for structural best management practices. These curves are excellent for purposes of comparison; however, it is recommended that construction and maintenance budgets should be based on site specific information. Utilizing the table below and the cost estimation worksheet, will allow designers to avoid over or under estimation of fixed costs.

The design infiltration rates

The table below lists the specific site components that are specific to infiltration practices. Not included in this table are those cost items that are common to all construction projects, such as mobilization, traffic control, erosion and sediment control, permitting, etc.

Infiltration trench and infiltration basin cost estimate worksheet.
Link to this table

Project Title
Owner
Location
Project Number
Date
Description Units Quantity Unit Cost Total Estimated Price
Site Preparation
Tree removal - up to 12" diameter each $350.00 $0.00
Clear and grub brush square yard $1.50 $0.00
Tree protection - temp. fence lineal foot $3.00 $0.00
Infiltration area protection - silt fence lineal foot $2.00 $0.00
Topsoil - 6" depth, salvage on site square yard $4.50 $0.00
Site Formation
Excavation - 6' depth square yard $8.00 $0.00
Grading square yard $1.50 $0.00
Hauling off-site - 6' depth square yard $10.00 $0.00
Structural Components
Inlet structure each $1,500.00 $0.00
Multi-stage outlet structure each $2,500.00 $0.00
Site Restoration
Sod filter strip lineal foot $1.50 $0.00
Soil preparation square yard $5.00 $0.00
Seeding - above outlet elevation square yard $0.50 $0.00
Planting - below outlet elevation square yard $30.00 $0.00
Mulch square yard $2.00 $0.00
Subtotal $0.00
10% Contingencies $0.00
Subtotal $0.00
Apply MN Location Factor $0.00
TAL CONSTRUCTION COST $0.00
Annual Operation and Maintenance
Replace planting media square yard $12.00 $0.00
Debris removal per visit $50.00 $0.00
Mow filter strips per visit $50.00 $0.00
Sediment removal per year $500.00 $0.00
Replace plants per plant $5.00 $0.00
Erosion repair square yard $75.00 $0.00
Gate / valve operation per visit $125.00 $0.00
Inspection per visit $125.00 $0.00
Subtotal $0.00
Apply MN Location Factor $0.00
TOTAL ANNUAL O&M COST $0.00
Minnesota Location Factors
Bemidji 0.963
Brainerd 1.003
Detroit Lakes 0.962
Duluth 0.991
Mankato 0.990
Bemidji 0.963
Minneapolis 1.035
Rochester 0.983
St. Paul 1.000
St. Cloud 1.002
Thief River Falls 1.042
Willmar 0.961
Windom 0.935

Note: Suggested unit costs are based on RS Means prices for Spring, 2005, then factored into an area basis based on typical design features for Constructed Wetlands BMPs. To be used for preliminary cost estimation