PROJECT SCOPE OF WORK CITY OF TOWN AND COUNTRY STORMWATER PROGRAM

Transcription

1 PROJECT SCOPE OF WORK CITY OF TOWN AND COUNTRY STORMWATER PROGRAM Project Name: 194 Muir Woods Ln Project ID Number: Problem: At 194 Muir Woods Lane, nearly two acres of watershed flow through the backyard. The homeowner has installed rock-lined swales to convey some of the runoff through the backyard lawn to the driveway or to the wooded hillside. Two rock swales concentrate and convey stormwater through the yard to the downhill side along the south property line and discharge to rills running through a steep wooded hillside. Ground cover on the hillside is leaf litter. The rills are eroding and progressing to swales or gullies. Farther downstream, 1961 Muir Woods Lane is located at the bottom of the hill. The property owner has installed a rock blanket swale to divert the runoff to a creek on the west side of that lot. Both sides of the swale are bare soil and a small amount of erosion is occurring along both sides of the rock blanket swale. During a conversation with the homeowner of 1961, they reported no concern about stormwater runoff they are satisfied that the rock blanket swale that they installed years ago is sufficient. Proposed Solution: Install a berm and swale on the north side of the property at 194 Muir Woods Lane to direct runoff into a proposed area inlet on the northeast corner of the property. The inlet will be piped south down the right-of-way on Muir Woods Lane, connecting to proposed inlet near the southeast section of the cul-de-sac. This inlet will connect to the existing inlet in the cul-de-sac, 22P2-6D. Required Easements: 191 Muir Woods Lane (Temporary Construction Easement) 194 Muir Woods Lane (Temporary Construction Easement) 1961 Muir Woods Lane (Temporary Construction Easement) Commentary: A prior alternative to the project was installation of a leveling box and riprap on the upper reaches of erosion rills is a small project that might be suitable for the City of Town & Country Storm Water Maintenance Policy. The project scope has increased to provide a more complete stormwater solution. PROJECT SCOPE OF WORK

2 PROJECT INFORMATION SUMMARY CITY OF TOWN AND COUNTRY STORMWATER PROGRAM Project Name: 194 Muir Woods Ln Project ID Number: Number of Properties Impacted: Number of Easements Required: Number of Properties Benefited: Opinion of Probable Construction Cost (OPC): Location Benefit Identification (LBI) Project Points: $11, Project Source: x Citizen Complaint Municipality Maintenance Government Agency Category of Problem: Description Cost to Benefit Ratio: 1,16 Coordination Required: x MSD Corps of Engineers MO DNR MODOT County Highways City Streets City Parks County Parks x Municipality: City of Town & Country Railroad: x : Utility Service Providers Attached Supplemental Information: x Project Scope of Work x Conceptual Plan Drawing x Itemized Opinion of Probable Construction Cost (OPC) x Location Benefit Identification (LBI) Forms x Existing Condition Photos A: Frequent structural flooding from creeks or rivers (floodplain) B: Frequent structural flooding from overland flow (non-floodplain) C: Frequent roadway flooding D: Infrequent structural flooding from creeks or rivers (floodplain) x E: Infrequent structural flooding from overland flow (non-floodplain) x F: Infrequent roadway flooding G: High risk structural erosion H: High risk roadway erosion x I: Yard erosion J: Moderate risk structural erosion x K: Moderate risk roadway erosion L: Erosion or flooding of common ground or unmaintained area x M: Yard flooding N: Flooding from inadequate sinkhole O: Flooding from inadequate roadway drainage P: Maintenance of stormwater system facilities Q: Notes: MSD/MO American Water Base Map Number(s): FEMA FIR Map Number(s): 22P 29189C1K PROJECT INFORMATION SUMMARY

3 OPINION OF PROBABLE CONSTRUCTION COST CITY OF TOWN AND COUNTRY STORMWATER PROGRAM Project Name: 194 Muir Woods Ln Project ID Number: ITEM ESTIMATED UNIT EXTENDED NUMBER PAY ITEM DESCRIPTION QUANTITY UNIT PRICE PRICE 1 Mobilization 1 Lump Sum $2,287. $2, Clearing 1 Lump Sum $1,. $1,. Excavation Class "C" 19 Cubic Yards $28. $,2. 4 Inlet - Area 2 Each $2,. $4,1. Pipe Sewer 12 Inch (Storm) 2 Each $9. $22,. 6 Connection to Existing Manhole 1 Each $,1. $,1. 7 Berm 2 Linear Feet $12. $,. 8 Street Pavement - Asphaltic Rem. and Rep. 1 Square Yards $8. $8,. 9 Sodding - Fescue 1 Square Yards $11. $1,72. 1 Protection and Restoration of Site 1 Lump Sum $9,911.8 $9,911.8 SUB-TOTAL - CONSTRUCTION: $88,444.2 Estimated Engineering Fee: $18,. Estimated Geotechnical Engineering Fee: $. Estimated Property Survey/Strip Map Preparation Fee: $1,9. Estimated Property Title/Easement Search Report Fee: $1,2. Estimated Topographic Survey Fee: $2,. Estimated Property Rights Acquisition Document Preparation Fee: $1,. Estimated Cost of Easements: $,. Estimated Construction Survey Fee: $. SUB-TOTAL: $116,444.2 % Contingency: $4,9.26 TOTAL: $11,77.46 OPINION OF PROBABLE CONSTRUCTION COST

4 City of Town & Country Location Benefit Identification Project Name: 194 Muir Woods Ln Project Id Number: Location Address / Description: 191 Muir Woods Lane Total Calculated Benefit Points: 1. Evaluation Category Problem Type Benefit Points High Medium Low Public Structure Residential Structure Retaining Wall (Public) Street ROW Improved Channel Retaining Wall (Private) Drainage Structure Yard Erosion Unimproved Channel Erosion Subtotal 6 Public Structure Residential Structure Impassable Traffic Passable Traffic Accessory Structure Yard Flooding Flooding Subtotal Drainage Structure Improved Channel Unimproved Channel Street Gutter Swale / Berm Maintenance Maintenance Subtotal Street Yard 1 Drainage Drainage Subtotal 1 Frequency Rating Degree of Risk >1 / year 1 Life / Limb 1 / year Health 1 / years Property Value.1 1 / 1 years Frequency Rating Multiplier 1 Degree of Risk Multiplier.1

5 City of Town & Country Location Benefit Identification Project Name: 194 Muir Woods Ln Project Id Number: Location Address / Description: 194 Muir Woods Lane Total Calculated Benefit Points: 12. Evaluation Category Problem Type Benefit Points High Medium Low Public Structure Residential Structure Retaining Wall (Public) Street ROW Improved Channel Retaining Wall (Private) 6 Drainage Structure 6 Yard Unimproved Channel 1 Erosion Erosion Subtotal 19 Public Structure Residential Structure Impassable Traffic Passable Traffic Accessory Structure Yard Flooding Flooding Subtotal Drainage Structure Improved Channel Unimproved Channel Street Gutter Swale / Berm 1 Maintenance Maintenance Subtotal 1 Street 1 Yard 1 Drainage Drainage Subtotal 2 Frequency Rating Degree of Risk >1 / year 1 Life / Limb 1 / year Health. 1 / years 1 / 1 years Frequency Rating Multiplier 1 Property Value Degree of Risk Multiplier.

6 City of Town & Country Location Benefit Identification Project Name: 194 Muir Woods Ln Project Id Number: Location Address / Description: 1961 Muir Woods Lane Total Calculated Benefit Points: 1.1 Evaluation Category Problem Type Benefit Points High Medium Low Public Structure Residential Structure Retaining Wall (Public) Street ROW Improved Channel Retaining Wall (Private) Drainage Structure Yard Unimproved Channel Erosion Erosion Subtotal 6 Public Structure Residential Structure Impassable Traffic Passable Traffic Accessory Structure Yard Flooding Flooding Subtotal Drainage Structure Improved Channel Unimproved Channel Street Gutter 1 Maintenance Swale / Berm Maintenance Subtotal 1 Street 1 Drainage Yard Drainage Subtotal 1 Frequency Rating Degree of Risk >1 / year 1 Life / Limb 1 / year Health 1 / years Property Value.1 1 / 1 years Frequency Rating Multiplier 1 Degree of Risk Multiplier.1

7 216-2 Project location at end of Muir Woods Ln. Can see steep slope of road. (216) 1961 Muir Woods Lane (216)

8 Muir Woods Lane. North and uphill from 1961 Muir Woods Ln. (216) Large parking area at 194 Muir Woods Ln. Steep slope to right of fence. Looking east towards street. (216) Some of stormwater in driveway shown above flows to southwest corner of pavement. (216)

9 216-2 West side of driveway. Can see rock swale. (216) Rock swale leading to channel. (216) End of rock swale. Looking downstream. (216)

10 216-2 End of rock swale. (216) Looking downstream from rock swale. Slope flattens out, then becomes steep again. Leads to rock channel constructed by 1961 Muir Woods Ln. (216)

11 216-2 Path of stormwater, northwest of home at 1961 Muir Wood Ln. (216) Owner place rock blanket approximately 2 years ago, when property was purchased. (216) Steep slope on right bank (looking downstream). (216)

12 216-2 View upstream or northeast. Owner: No flooding concerns. Didn t seem to think there was any issue. (216) Looking upstream and at section of the channel. A lot of moss on banks. Can see stormwater path is beginning to cut around the rock blanket on either side. Not major concern since this is 2 years old. (216)

13 216-2 Shows very steep slope at the back of 1961 Muir Wood Ln, leading to channel (left bank). (216) Can see attempt at grade control. Located on right bank. Looks to be at the end of more concentrated flow running down slope from driveway at 194 Muir Wood Ln. (216)

14 199 U V ft Contours Existing 4 22P2-S, % Sanitary Manhole " ) Stormwater Inlet 4 Project Location, % # * V U Parcels Proposed 192 Proposed Improvements Strip Map Limits 194 FEMA Flood Hazard Zone Regulatory Floodway 1.% Annual Chance Flood Hazard.2% Annual Chance Flood Hazard 19 Easements Required Properties Impacted Properties Benefited Project Benefit Points Conceptual Cost Cost to Benefit Ratio P2-2S Overland flow is causing yard erosion and flooding, threatening a private retaining wall '' 22P2-66D 22P2-8S 12 '' 22P2-2S 22P2-127S 22P2-67S 1'' 1 '' 48 22P2-9S 12'' 22P2-81S 19 22P2-129S 22P2-49S '' P2-1S P2-128S 22P2-S P2-69D 2 22P2-67D 22P2-68D 1'' 1 1'' 12'' Feet 1 inch = 8 feet Warning: If this bar does not measure 1" then drawing is not to scale City of Town & Country Stormwater Program 11 22P2-82S '' 49 4 Install a berm to convey water to new inlets and extend the existing storm sewer system. 1'' Proposed Solution Description $11,78 1,16 Problem Description BARRETT STATION RD 194 Topo Limits Stormwater Gravity Main Pavement MUIR WOODS LN 1949 Stormwater Intake/Outfall Impervious 1 6 Stormwater Manhole Stormwater Channel 191 V U 7 Sanitary Gravity Main 194 Muir Woods Ln 216-2