Mill Pond Dam Modifications Feasibility Study

Village of Goodrich, MI

May 1, 2013

Mill Pond Dam Modifications Feasibility Study

Village of Goodrich - Mill Pond Dam Modifications Feasibility Study I

1. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Michigan Department of Environmental Quality (MDEQ) Regulation Dam Safety Unit Requirements . . . . . . . . . . . . . . . . . . . 1 1.2 Project Goals and Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2. Summary of Engineering Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1 Dam Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Hydrology and Hydraulics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3 Survey Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3. Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1 Preferred Short-Term Action Plan for Mill Pond Dam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Preferred Long-Term Action Plan for Mill Pond Dam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Conceptual Opinions of Probable Construction Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5. Implementation and Funding Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

List of Figures 1 Location Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 Topographic Elevations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Alternative 1 Site Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 Alternative 2 Site Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 Alternative 3 Site Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 Short-Term Actions Cost Estimate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Long-Term Alternatives Cost Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8PotentialFundingSourcesforMillPondDamModifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table of Contents

Village of Goodrich - Mill Pond Dam Modifications Feasibility Study 1

The Mill Pond Dam was constructed in 1913 for waterpower development and subsequently purchased by the City of Flint as a supplemental reservoir for public water supply in the 1970’s. Under a lease agreement, the Village of Goodrich is responsible for operating and maintaining the dam. A general location map is provided in Figure 1.

1.1 Michigan Department of Environmental Quality (MDEQ) Regulation Dam Safety Unit Requirements

The following excerpt is from the Mill Pond Dam Safety Inspection dated June 5, 2012.

On June 5, 2012, a Dam Safety Inspection was conducted and evaluated the structural condition and hydraulic capacity of this dam as required by Part 315, Dam Safety, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended. The results of this inspection documented that the dam is in fair condition overall. Based on observations at the time of the inspection there were no apparent structural deficiencies that may lead to the immediate failure of the dam. However, the structural elements of the dam continue to deteriorate. The dam has adequate spillway capacity to pass the design flood only if all stoplogs and lift gates are removed from the dam, which is questionable during high flow conditions. The following recommended actions are listed by priority.

1. Update the current operation and maintenance (O&M) plan by December 31, 2012, to include powerhouse stoplog removal. If modifications are needed in order to reliably remove the stoplogs

Section 1

Background

Figure 1 Location Map

Mill Pond Dam

Goodrich Mill Pond


during a flood, these modifications should be made by May 1, 2013. This was requested in 2004 and 2008 inspections and has not yet been completed. It is essential to be able to remove the stoplogs and lift gates from all five spillway bays in order to safely pass the design flood.

2. Remove the trees and brush growing near the left downstream abutment wall as well as any trees and brush growing through the concrete cap on the right downstream embankment by May 1, 2013. Provide photos to the Dam Safety Program of these areas once the trees and brush have been removed.

3. Within five years, develop a long-term plan for the future of the dam. This plan should include a structural analysis for the long-term stability of the dam as well as a feasibility study for repair, replacement, or removal of the spillway. When complete, provide a copy of the plant to the Dam Safety Program.

4. Monitor embankments for seepage and erosion on a quarterly basis.

5. In conjunction with the Genesee County Emergency Management, review and update the Emergency Action Plan (EAP) for the dam by December 31, 2012. Provide a copy of the updated plan to the Dam Safety Program.

The significant hazard potential rating for this dam remains appropriate.

Since this report was issued, the Village has prepared and the MDEQ has accepted the Emergency Action Plan noted in action item 1.

1.2 Project Goals and Objectives

During the planning workshop conducted with Village officials on April 3, 2013, project-specific goals and objectives were set to help guide the planning and design of the proposed modifications to the dam structure envisioned as a result of this effort. The following goals and objectives were identified:

Goals:

• Ensure the dam is safe for the downstream community and public/private infrastructure

• Save the Mill Pond impoundment for the community• Develop an Action Plan for safely passing flows• Determine funding options• Aesthetics should be addressed in the dam improvements• Maintain the use of the impoundment for Fire Protection as a water

source• Develop a plan that includes short-term as well as long-term actions

Objectives:

• Preserve the dam impoundment• Replace the gates to comply with MDEQ directives• Use alternative funding sources including state, federal and private

foundations to the greatest extent possible

The Village officials intend to use these goals and objectives to screen for the preferred alternative short-term and long-term actions as prepared by the engineering team during the evaluation phase of this scope of work.


Section 2

Summary of Engineering Investigations

The Wade Trim/Stantec Team performed visual inspections and reviewed published reports and public record data. In addition, Village staff and officials were interviewed about the maintenance and operation of the dam over the last several years. The engineering evaluation did not include any site-specific engineering testing or geotechnical investigations. Therefore, the recommendations that follow are based on qualitative assessments of the structure and surrounding site conditions. Limited additional topographic data was collected to support the hydraulic investigations performed as part of this work. However, this was limited to Hegel Road Bridge and the spillway canal area of the structure.

2.1 Dam Structure

The dam structure consists of earthen embankments with a structural height of 22 feet and a hydraulic height of 19.4 feet. It creates an impoundment with an estimated surface area of 14 acres. The 180-foot-long left embankment has an approximate crest width of 135 feet, an approximate upstream slope of 2 horizontal to 1 vertical, and a downstream slope of 3 horizontal to 1 vertical. The 50-foot-long right embankment has an approximate crest width of 90 feet, an approximate upstream slope of 2 horizontal to 1 vertical, and a downstream slope of 1.5 horizontal to 1 vertical.

A spillway channel exists under Hegel Road as well as a spillway with six stoplog controlled bays as shown in the adjacent photos. The overflow spillway is controlled by three 5.2-foot-wide stoplog bays, and flow through the former powerhouse is controlled by two 5.5-foot-wide stoplog bays. Flow through the fish ladder is controlled by a single, 5.2-foot-wide stoplog bay. Prior to reaching the spillway crest, flow from the Goodrich Mill Pond passes under the Hegel Road Bridge through a

short, concrete-lined channel that is in satisfactory condition prior to reaching the spillway crest.

Flow through the principal spillway is controlled by lift gates consisting of stoplogs attached to lifting arms to facilitate lifting of the stoplogs. The spillway discharges to Kearsley Creek. Stop logs for the powerhouse area and fish ladder are not equipped with a lifting mechanism. Removal of these stoplogs is difficult during periods of high flow and is not considered to be in an operable state unless the impoundment is drawn down to an elevation below the stoplog crest.

The overall condition of the concrete principal spillway is poor. Deterioration of the concrete structure is pervasive as is common for older concrete structures that were not constructed with air-entrained concrete. Concrete repairs have been made throughout the structure. In addition, we noted concrete (flowable fill) has been poured under and around the spillway, most recently in 2007. Large voids in these areas of the spillway structure raise concern over the stability of the spillway. A more detailed engineering subsurface investigation should be performed as part of the long-term action plan for the dam repair.

2.2 Hydrology and Hydraulics

The contributing drainage area of Kearsley Creek at the Mill Pond Dam and upstream impoundment is approximately 52 square miles. Based on information provided in the Dam Safety Inspection Report-MDEQ, dated June 5, 2012, the design discharge rate from the 200-year design storm is 1,580 cubic feet per second (cfs). The capacity of the dam spillway is controlled using three small and two large control gates that are manually operated by Goodrich staff. Currently only the three small control gates

Two powerhouse gates and a fish ladder gate at the far left of the spillway structure are not considered operable at high water elevations.

Three operable gates located at the far right of the spillway structure are used to control overflow.


Elevation Description881.14 Chiseled “X” top of wall between gates 1 & 2 (BM # 5)875.17 Top of concrete of fish hute875.54 Bottom of Slab 5 (westerly most gate)875.56 Bottom of Slab 4 875.61 Bottom of Slab 3 875.61 Bottom of Slab 2875.58 Bottom of Slab 1 (easterly most gate)877.87 Top of storage (abutment wall) east side877.67 Top of storage (abutment wall) west side

865.57 River bottom between bridge and dam - assumed concrete bottom

865.70 River bottom - lake side, south of bridge875.02 Low beam on Hegel Bridge (north side of bridge)873.89 Lake elevation mark (west side of bridge)858.10 Water surface elevation north of dam873.78 Water surface elevation between dam and Hegel Bridge873.76 Water surface elevation - lake side, south of bridge

Figure 2 Topographic Elevationsare operable while the two larger gates remain fixed in a closed position without any means of operation. The dam spillway was designed with the intent of having all 5 gates fully operational. Recent hydraulic calculations show that with all five gates in a fully open position, the 200-year-design flow of 1,580 cfs can safely pass through the spillway while maintaining an acceptable hydraulic grade line (HGL) elevation of 875.5 feet immediately upstream of the dam. However, with only the three smaller gates; those that are currently operational and raised to the fully open position, the maximum passable flow while maintaining the same upstream HGL of 875.5 feet is approximately 740 cfs. In order to pass the full 1,580 cfs design flow, the upstream HGL must increase. This increased HGL causes higher floodplain elevations upstream in the impoundment that may result in overtopping of the roadway and the earthen embankment at an area near the existing bridge and spillway channel.

2.3 Survey Data Collection

To predict the potential hydraulic conditions and determine critical grades for conceptualizing the alternative solutions, the design team collected additional topographic elevations at critical areas of the existing dam structure and embankment. Figure 2 summarizes the grades and elevations collected during this survey. All grades are based on a benchmark control point #100; a 5/8” Iron with Brass Disk in Goodrich Park on NAVD88 survey datum.

Water surface and lake bottom elevations surveyed during this assessment indicate the Mill Pond water depth is reducing from sedimentation. In some cases, bottom sediments were noted to be less than 8 feet below the water surface. Sedimentation within the Mill Pond will be a significant aesthetic and functional change in the Mill Pond. Dredging costs were not evaluated in this effort, but are estimated to be significantly higher than the costs of any of the long-term alternative action plans.

Goodrich Park will become more directly connected to the floodplain with the proposed dam improvements.

“Hungry water” downstream of the dam has caused large areas of the existing banks to erode, especially near the spillway stilling basin at the bottom of the spillway flumes.


Section 3

Recommendations

A matrix of feasible short-term and long-term alternatives to meet the MDEQ requirements and address the aging dam structure was developed. A range of short- and long-term options were evaluated during the April 3, 2013, workshop with Village officials and project stakeholders.

Short-term actions evaluated:

• Repair powerhouse gates to be operative• Replace powerhouse gates with new gates• By-pass high flows with lower road surface for Hegel Road• Construct a downstream coffer dam to contain Mill Pond• Lower the impoundment’s water surface level• Construct a high flow by-pass channel

Long-term actions evaluated:

• Repair/replace dam with active gates• Remove dam and replace with a principal channel rock ramp and

auxiliary spillway• Remove the dam• Remove dam and place an upstream weir/step structure

3.1 Preferred Short-Term Action Plan for Mill Pond Dam

Based on the qualitative engineering evaluations performed during the dam condition assessment phase, the Wade Trim/Stantec Team recommended the powerhouse gates either be replaced or repaired to be operative as required by the MDEQ in their latest correspondence with the Village. As a result of the dam modification study alternatives workshop conducted on April 3, 2013, with Village officials and project stakeholders, this short-term action was preferred due to its straightforward approach and relatively low cost to implement.

After the workshop, the Wade Trim/Stantec Team investigated the feasibility of modifying the gates to have a 3-foot removable section on top and a fixed lower portion. This modification was investigated relative to the hydraulic performance of the dam structure and deemed to be an acceptable alternative.

Sequencing of the permitting, engineering and implementation of this recommended solution includes:1. Conduct a pre-application conference with the MDEQ Dam Safety

Unit to include a summary of the proposed repair sequence and the necessary hydraulic calculations to support the powerhouse gate repair.

2. Prepare and submit an MDEQ Part 315 permit application for the gate repair.

3. Lower the impoundment elevation temporarily to eliminate any flow over the powerhouse gates to allow for inspection, engineering design and construction of the gate repair.

4. Develop plans and bidding documents and bid and construct the work as may be required by the Village.

The work is estimated to be completed in no more than three months from the notice to proceed, dependent on weather conditions, permit approvals and the selected contractor’s schedule.

3.2 Preferred Long-Term Action Plan for Mill Pond Dam

Planning workshop participants evaluated a range of long-term actions that would provide for the ultimate long range plan for addressing the risks and liabilities of owning the dam. Given the cost and complexity of the long range plan, implementation of any of the solutions will be a significant public investment and require considerable coordination and time to coalesce the funding for a comprehensive solution to replacing the aged dam structure with a functional and cost effective dam structure. After the long-term solutions were evaluated, three preferred alternatives were selected that are generally similar in function, benefits and expected cost, but not necessarily in form.


Preferred Long-term Alternative 1Alternative 1 moves the spillway from the existing dam structure downstream in the form of a rock ramp grade control structure as shown in Figure 3. This concept sets the invert at a slightly lower impoundment elevation of 873.5 (Existing 874) and proposes high flows to be routed across an expansive overflow berm into the existing floodplain in Goodrich Park. The overflow berm would be constructed in a manner to channel the regular base flow and high frequency flows across the rock ramp. However, flood flows would crest over the overflow berm in a controlled manner on the downstream side of the dam. The overflow berm would be constructed of a rock/soil matrix and heavily landscaped pockets with deep rooting native grasses and forbs to further protect the overflow berm from erosion during high flow events. Because these high flows would be infrequent and crest across a broad overflow area, erosive velocities would be minimized and the existing floodplain would be accessed across a broad area of the existing park. The alternative will require installation of a seepage cutoff along the entire length of the containment area for the downstream impoundment at both the rock ramp channel and the auxiliary overflow channel. The containment dike could be constructed of either steel sheet pile or a slurry trench. The existing dam structure would remain in place, however, all the existing stoplog gates would be removed to allow a free flowing condition through the structure, thereby greatly reducing stress from hydraulic loading on the existing structure. The top of the existing structure is proposed to be repurposed to allow for public observation of the expanded impoundment area created downstream by the proposed rock ramp structure.

Alternative 1 benefits:

• Passive management of flows; no gate operation or related maintenance is required

• Improved public recreational opportunities in Goodrich Park with the addition of the impoundment area for fishing and passive waterfront access

• Improved landscape quality of Goodrich Park with the addition of the heavily planted berm and rock ramp cascade

• Preservation of the historic Mill Pond Dam structure for community interest and historic/cultural interpretation of the former mill and history of the region

• Preserves water supply capacity as a result of the expanded impoundment area

Preferred Long-term Alternative 2Alternative 2, shown in Figure 4, moves the spillway upstream, south of the existing dam spillway and the Hegel Road Bridge. The new spillway structure is designed to be multi-functional to control the water level of the impoundment, implement a seepage cutoff, and provide an elevated recreational overlook/fishing access promenade. The proposed spillway is sized with a weir length capable of passing the critical storm flow. The top of the first rock ramp is to be set approximately 4 feet below the top of the spillway. Normal flows will pass from the spillway through the proposed rock ramps and the existing channel of Kearsley Creek. However, high flows will overtop the bank of the channel and spill into the existing floodplain within Goodrich Park. Both banks of Kearsley Creek will be stabilized with bioengineering to prevent scour of the banks and provide restored riparian habitat within the park.

The pedestrian promenade over the spillway will allow improved public access to the Mill Pond for passive recreation including fishing. An access area will be located at the eastern edge to allow canoe and kayak launching. Pedestrian connections will be added to the sidewalks along Hegel Road as well as pedestrian connections along the Kearsley Creek channel in Goodrich Park.



• Improved recreational opportunities in Goodrich Park with the addition of public access to the Mill Pond for fishing and non-motorized boating access

• Improved landscape quality of Goodrich Park, restored creek channel and stabilized banks

Preferred Long-term Alternative 3After reviewing Alternatives 1 and 2, the workshop participants evaluated a hybrid of the two alternatives which essentially combines the most desired features and qualities into a single hybrid concept. Alternative 3, shown in Figure 5, combines the expanded recreational benefits found in Alternative 2 with the downstream passive control of the impoundment as detailed in Alternative 1. Alternative 3 includes a canoe and kayak launch on the south main Mill Pond area as well as a fishing access platform at the eastern edge of the Mill Pond along Hegel Road. In addition, a pedestrian path across the existing dam structure is extended along the top of the overflow berm and enhanced with fishing access overlooks at strategic points including the top of the rock ramp near the principal channel crest.



• Improved public recreational opportunities in Goodrich Park with the addition of the impoundment area for fishing and passive waterfront access

• Improved landscape quality of Goodrich Park with the addition of the heavily planted berm and rock ramp cascade

• Improved public access to the historic Mill Pond impoundment for non-motorized boating and fishing

• Preservation of the existing dam structure as a public historic amenity and recreational overlook space

• Preserves water supply capacity as a result of the expanded impoundment area


Bank Stabilization and Restored Riparian Area

Principal Channel Rock Ramp

Auxiliary Overflow

Enhanced Landscape Treatment at Public Parking Area

Preserved Historic Mill Pond Dam

North

Hegel Road

M - 15

Figure 3 Alternative 1 Site Plan


Bank Stabilization and Restored Riparian Area

Rock Ramp No. 2

Rock Ramp No. 1

Existing Public Parking Area

Spillway and Cascade Water Feature

Pedestrian Promenade and Fishing Access

North

Hegel Road

M - 15



Rock Ramp Spillway

Auxiliary Overflow

Pedestrian Path and Fishing Access

Expanded Spillway Basin

Overlook and Preserved Historic Mill Pond Dam*All Gates Removed

Enhanced Landscape Treatment at Public Parking Area

Fishing Platform

Canoe / Kayak LaunchNorth

Hegel Road

M - 15



Section 4

Conceptual Opinions of Probable Construction Costs

Figure 7 Long-Term Alternatives Cost Estimates

Item No. Description Quantity Unit Unit Cost Extension

Alternative 11 Mobilization (5%) 1 LS $79,146 $79,146 2 Dam Gate Removal-Selective Demolition 1 LS $7,500 $7,500 3 Paving and Grading of Parking Area 3,085 SF $8 $24,680

4 Sheetpile Cutoff Wall along Auxillary Overflow and Main Channel 305 LF $1,600 $488,000

5 Rock Ramp Construction (Assume 2 feet of Boulder Mix over engineered soil 1,214 Tons $75 $91,050

6 Rock Ramp Engineered Fill (Assume 6 Feet Avg Depth) 2,043 Tons $35 $71,505

7 Overflow embankment ( Assumes 3 feet of Boulder/Soil Mix and Fill Material) 5,600 Tons $65 $364,000

8 Earthwork -Excavation and Grading 200 CY $14 $2,800

9 Bioengineering Bank Stabilization and Riparian Plantings-Low Bank Area 4,092 SF $15 $61,380

10 Bioengineering Bank Stabilization and Riparian Plantings-High Bank Area 12,400 SF $30 $372,000

11 Landscape Planting at Overflow and Parking Area 1 LS $100,000 $100,000 12 Contingency (25%) 1 LS $415,515 $415,515

TOTAL $2,078,000

NOTE: Other project costs including grant assistance, design engineering, permitting, construction engineering, and legal and bond counsel, are not included in this table.

Figure 6 Short-Term Actions Cost Estimate


Temporary Modifications to Powerhouse Inlet Gates1 Mobilization and site access 1 LS $5,000 $5,000

2 Remove top 3 feet of old sluice gates, install bracing angle on remaining gate 2 EA $1,000 $2,000

3 Install 2 x 3 angles on inside wallface 4 EA $900 $3,600

4 Construct new 5.5’w x 3’ high wooden gates with lift plank 2 EA $2,200 $4,400

5 Install new gates 2 EA $750 $1,500 6 Demobilize and cleanup 1 LS $1,000 $1,000 7 Contingency (25%) 1 LS $4,000 $4,000

TOTAL $21,500


NOTE: The engineer has no control over the cost of labor, materials, equipment, or services furnished by others, or over the contractor’s method of determining prices, or over competitive bidding or market conditions. Opinions of probable project costs and construction costs provided herein are made on the basis of the engineer’s professional judgment and experience. The engineer cannot and does not guarantee that proposals, bids or actual project or construction costs will not vary from the prepared opinion of probable cost.



Alternative 3 Estimate of Probable Construction Costs1 Mobilization (5%) 1 LS $95,293 $95,293 2 Dam Gate Removal-Selective Demolition 1 LS $7,500 $7,500 3 Paving and Grading of Parking Area 3,085 SF $8 $24,680

4 Sheetpile Cutoff Wall along Auxillary Overflow & Main Channel 305 LF $1,600 $488,000

5 Rock Ramp Construction (Assume 2 feet of Boulder Mix over engineered soil 1,214 Tons $75 $91,050

6 Rock Ramp Engineered Fill (Assume 6 Feet Avg Depth) 2,043 Tons $35 $71,505

7 Overflow embankment ( Assumes 3 feet of Boulder/Soil Mix and Fill Material) 5,600 Tons $65 $364,000

8 Pedestrian Path Fishing Access Lower Impoundment 2,546 SF $12 $30,552 9 Canoe/Kayak Launch Platform 2,065 SF $80 $165,200

10 Fishing Access Platform 1,590 SF $80 $127,200 11 Earthwork -Excavation and Grading 200 CY $14 $2,800



14 Landscape Planting at Overflow and Parking Area 1 LS $100,000 $100,000 15 Contingency (25%) 1 LS $500,290 $500,290

TOTAL $2,501,450


Figure 7 Long-Term Alternatives Cost Estimates (cont’d.)


Alternative 21 Mobilization (5%) 1 LS $79,251 $79,251 2 Dam Structure Removal 1 LS $50,000 $50,000 3 Concrete Cascades below spillway 415 LF $130 $53,950 4 Sheetpile Cutoff at Spillway 326 LF $1,600 $521,600 5 Concrete Wingwall at Spillway 148 LF $150 $22,200

6 Concrete Promenade with Concrete Baluster and Lighting 3,083 SF $80 $246,640

7 Plantings at Spillway Structure 1,900 SF $2 $3,800 8 Rock Ramp Construction - Upper Ramp 690 Tons $75 $51,750 9 Rock Ramp-Upper Ramp Engineered Fill (8 Ft Avg Depth) 1,840 Tons $35 $64,400

10 Rock Ramp Construction - Lower Ramp 661 Tons $75 $49,575

11 Rock Ramp- Lower Ramp Engineered Fill (3.5 Ft Avg Depth) 771 Tons $35 $26,985

12 Earthwork -Excavation and Grading 200 CY $14 $2,800



15 Contingency (25%) 1 LS $416,069 $416,069 TOTAL $2,080,345



Section 5

Implementation and Funding Alternatives

The key to implementing the alternatives considered in this study is to consider replacing the Mill Pond Dam as a long-range plan with a broad foundation for continuing community focus and convergence on waterfront access, resource protection, recreation improvements and water management infrastructure in the Village of Goodrich. The Village should view the long-range plan as a multi-objective master plan that will be implemented over an extended time horizon. Implementation will require the Village to be flexible and continually update the plan as it moves forward in the years ahead. It is not unrealistic to think that the program elements in this study could take a decade or more to complete. Major steps to include are:1. Adopt an MDEQ-approved community recreation plan that includes a

project-specific Master Plan for the Mill Pond area2. Determine who will lead and manage implementation of the plan3. Communicate the plan4. Prepare preliminary specific plan phases for the project area5. Design/engineer and implement project phases as funding is procured

Having local leadership and administration demonstrates local commitment to the project and bridges the gap of various county, state and federal funding sources. This local commitment can be realized by establishing a project-specific task force that will provide direction and continuity of intent through multiple phases of development and changes in leadership within the Village.

In the absence of a dedicated funding program for dam rehabilitation and removal in Michigan, alternatives funding sources are limited. However, if the proposed modifications to the existing dam can be framed within a broader set of public improvements such as recreation, open space, and natural resource enhancements, the overall project may secure funding from an expanded pool of resources. This approach to funding is relatively new, yet the sources shown in Figure 8 are believed to be eligible to coalesce into a funding pool for a large part of the potential costs associated with any of the long-term alternatives.

Funding Agency Program FundingMichigan Department of Natural Resources Dam Management Grant Program $2.35 M (2012)*

Natural Resources Trust Fund $6.8 M (2012)*Inland Fisheries $5K - $200K

50% of total costMichigan State Historic Preservation Office Historic Preservation Grant Program 60-40 Matching

Grant in AidFederal Emergency Management Agency Pre-Disaster Mitigation Grants 75-25 Federal

to Non-FederalPrivate Foundations TBD Varies

* Total available funding for the fiscal year

Figure 8 Potential Funding Sources for Mill Pond Dam Modifications

555 S. Saginaw Street Suite 201 Flint, MI 48502810.235.2555800.841.0342www.wadetrim.com

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Mill Pond Dam Modifications Feasibility Study