APPLICATION FOR HAZARD MITIGATION GRANT

Transcription

1 Project Number South Dakota Office of Emergency Management 118 W. Capitol Ave Pierre, SD APPLICATION FOR HAZARD MITIGATION GRANT This application is for a Hazard Mitigation Grant under the provisions of the Stafford Act (Public Law , as amended). The following information is furnished in support of this application. Note to preparer: Any additional sheets required for responses and attachments should be placed with the part in which they are referenced. If subsequent references are made to the same material, a reference to that section is sufficient. Title: Spring Creek Tributary Mitigation Project PROJECT INFORMATION Date of Submission: Type of Submission: HMGP Project Application FIPS Code: Declaration: APPLICANT INFORMATION Name Type County Indian Tribe Private Non-Profit Special District Other Name: Jon Peters Title: Lincoln County Flood Plain Administrator Address: 104 N Main Street Suite 240 CONTACT PERSON City: Canton ID:SD Zip: Phone: Fax:

2 APPLICANT INFORMATION ALTERNATE CONTACT PERSON Name: Tucker Halverson Title: Lincoln County GIS Technician Address: 104 N Main Street Suite 240 City: Canton ID Zip: Phone: Fax: Name: Dennis Weeldreyer Title: Lincoln County Commission, Chairman Address: 908 W 2 nd Ave. APPLICANT'S AGENT City: Lennox ID: SD Zip: Phone: Fax: Attach a copy of the document appointing the Applicant's Agent as empowered to act on behalf of the applicant with regards to this grant application and project.

3 PROJECT DESCRIPTION Type Acquisition Relocation Elevation Flood protection Project Description: Storm Shelter Power Line Burial Other Lincoln County is proposing to use Federal Emergency Management Agency (FEMA) Hazard Mitigation Grant Program (HMGP) funds to make drainage improvements to the Spring Creek Tributary and Spring Creek just southeast of Sioux Falls, SD. Please see attached project map. Improvements will increase conveyance capacities by increasing the sizes and type of culverts and constructing channel improvements in order to lower base flood levels, prevent road damage and loss of access. The project begins with minimal channel increases upstream of SD Hwy 11. The twin 48 x100 RCPs at the north crossing of SD Hwy 11 will be replaced with a 100 double barrel 12 x6 Reinforced Concrete Box Culvert (RCBC). This double barrel precast box culvert is estimated at a cost of $200,000. At the south crossing of SD Hwy 11 the existing 24 x78 RCP will be replaced with a twin 36 x78 RCP with flared end sections. The twin 36 x78 RCPs are estimated to cost $20,280. Just downstream of Hwy 11, a private driveway will be converted into a low-water crossing, with twin 36 CMP to handle low flows. From just downstream of Hwy 11, downstream to 270th Street, capacity increases will be designed above and outside of the current streambed and bank in order to maintain or lower the Base Flood Elevation (BFE). At Cody Road the single 6 x52 CMP will be replaced with a 6 x52 Arch CMP at a cost of $13,000. A 7 x50 RCP with a flared end section will be added to the existing single 6 x50 CMP at the west crossing of 85th Street (270th Street) at a cost of $21,500. To prevent overtopping in a 100-year event, the existing 3.5 x50 CMP at the east crossing of 85th Street (270th Street) will be replaced with twin 4 x50 RCPs with flared end sections at a cost of $14,000. At the north crossing of Split Creek, the existing structure will be replaced with a double 12 x5 RCBC to lower the BFE in this area, and to prevent overtopping of the roadway during the 100-year event. The south crossing will have a 7 x70 CMP added to the existing twin 5 x70 CMPs at a cost of $16,800. Chateau Ct currently has twin 5 x144 CMPs where a 6 x144 CMP will be added at a cost of $30,240. The Spring Creek Tributary railroad-crossing embankment will be modified to achieve a no-rise in a 100-year event. On Spring Creek at Saddlerock Place, the existing twin 6 CMP will be replaced with a double 12 x9 RCBC. This will lower the BFE below the adjacent affected structure, and will also prevent overtopping of the roadway during the 100-year event. The end of the project will consist of raising the road at 479th to create storm water detention to mitigate the effects from the upsizing of the various pipes upstream on Spring Creek Tributary and Spring Creek. The outlet structure for this pond will utilize the existing double barrel RCBC, as well as a weir overtopping section for handling events greater than the 100-year event (roadway will function as the weir). This outlet will also include additional erosion protection measures to handle increased flows. Useful life of project (years): 50 Years Location: The Spring Creek Tributary has its headwaters within the City of Sioux Falls and discharges into Spring Creek 3.5 miles to the south east. Spring Creek has its headwaters within the City of Sioux Falls also and meets with the Spring Creek Tributary 5.5 miles to the east south east and discharges into the Big Sioux River 2.5 miles to the East. The project area is located to the southeast of Sioux Falls, SD, near the intersection of SD Hwy 11 and 270th Street (85 th St) extending near the intersection of 271 st St and 479 th Ave. The study area is located in the SE¼ of section 17, the SW¼ of Section 16 and the E½ of section 21, Township 100N, Range 49W of the 5 th PM.

4 PROJECT DESCRIPTION Problem Description: Storm water runoff travels through multiple subdivisions along the Spring Creek Tributary. This runoff must pass through culverts and channels of insufficient size and capacity causing flood water backup and ponding that damages homes, property and infrastructure. Low topography and obstructive infrastructure in the upper portion of the project area mandates increasing culvert sizes and hinders use of typical channel improvements alone to lower base flood elevations. Generous elevation changes and steep topography through the lower area increases erosion potential and makes detention difficult. A regional solution is necessitated by impacts affecting multiple subdivisions over a large area. Periodic flooding events are causing overtopping of roads and damage to homes, contents and road infrastructure. 20 residences are damaged by flooding events within the 100-year flood plain of Spring Creek and its tributary. Flooding above the 50 year event overflows the channel at Hwy 11 and is diverted south over driveways and Julie Road into what is best characterized as a closed basin that currently only has a 2 foot culvert outlet. This has resulted in damage to 9 out of the 20 affected residences. Several roads are being repeatedly damaged by flow rate and erosion. Access to 22 homes is prevented by overtopping flood waters and washed out subdivision roads. Overtopping of roads also affects regional traffic routing. Indicate maps attached USGS 1:100,000 USGS 1:24,000 FIRM County City Plat Other NWI Wetland Map How project reduces hazard's effects and solves the problem: 1. Larger culverts will reduce flood water buildup and ponding to lower flood levels throughout the project area below structure damage levels. 2. Larger culverts will pass the 100 year event at Hwy 11, Split Creek north crossing and Saddlerock Pl to eliminate loss of access due to road overtopping 3. The lowering of the Cody Rd street surface will lower flood water levels below structure damage levels. 4. Channel capacity increases will reduce surface water flood levels and subsurface effects to homes, basements and septic systems. 5. Detention ponds will detain extra flow levels caused by improved runoff efficiency of the project and meter the outlet discharges to pre-project amounts. Number of people 92 protected by project: Value of property $2,266,392 protected by project: Describe any future or planned projects that may impact the proposed project area: City of Sioux Falls development will occur upstream of the Spring Creek Tributary project area. Detention of city runoff is planned to minimize impact on the proposed project site. See attached City of Sioux Falls Storm water BMP Master Plan for details. There are no other planned future projects or proposed projects within the project area or within the Spring Creek Tributary s 100-year flood plain.

5 Describe damage caused by this disaster DAMAGE OVERVIEW Flash flooding events and residual flooding have periodically caused the banks of the Spring Creek Tributary to overflow in the Elmen Acres Addition, the Hanson s Addition, the Mystic Ridge Addition, and the Twin Creek Addition. Additionally Spring Creek has been known to impact the Twin Creek Addition. The damages caused by the Spring Creek Tributary and Spring Creek flood hazard include damages to homes and contents to homes located within the project area. Local roads and other infrastructure have also been impacted by the flood hazard. The homes along the Spring Creek Tributary in Elmen Acres subdivision are affected by flood water backup caused by inadequate culverts under SD Hwy 11. For the same reason many homes south of the main channel are affected by flood water overtopping the driveway adjacent to the main channel that is nearly the same elevation as Hwy 11. Flood events over a 50 year event proceed over this substantial barrier and then over Julie Rd and then over a series of driveways along the west side of the Hwy into a basin area served only by one 2 foot culvert. Roads are washed out and overtopped causing loss of access The damages caused by the flood hazard include damages to homes and contents to homes located within the project area. Local roads have overtopped and other infrastructure has also been impacted by the flood hazard. Has the building of new structures or other development changed the potential for future damage? The project will reduce flooding within the project area and prevent future property and infrastructure damages. The placement of channels, the increase in culvert sizes, and the utilization of detention combine to make a sustainable water coarse. Did FEMA/State Public Assistance staff write a project worksheet (PW) for any portion of this project or project area? Yes No If yes, provide the PW number(s) PA-08-SD-1915-PW-STP3 Describe damage caused by previous events Year, Month Description Severity Damage ($) Hzd Frequency July 2010 Damages to homes, personal property, culverts and roads $71,409 March/April 2007 Culvert Replacement and gravel $6,485 July 2010 Culvert Replacement and gravel $9,343.55

6 COST ESTIMATE Mobilization Clearing Excavation Channel Excavation Contractor Furnished Borrow Salvage, Stockpile, & Place Topsoil Remove Asphalt 6 Asphalt Concrete $100, $5, $26, $110, $180, $10, $2, $12, Aggregate Base course $23, Remove Pipe Culvert $11, Double Barrel 12 X6 RCBC $200, Double Barrel 12 X5 RCBC $125, Double Barrel 12 X9 RCBC $354, CMP $30, CMP $18, CMP ARCH $13, RCP W Flared End $20, RCP W/ Flared End $16, RCP W/ Flared End $21, Outlet Control Structure $15, Traffic Control $20,000.00

7 Riprap & Drainage Fabric $8, Seeding, Fertilizer, & Mulching $15, Miscellaneous Erosion and Sediment Control $40, Erosion Control Fabric $5, Utility Relocation $50, Land Rights Acquisition $72, Professional Services Construction Design $168, Professional Services Construction Administration $168, Professional Services Preliminary Design for BCA Analysis $50, Professional Services Grant Administration $25, Professional Services Environmental & Cultural Resources $55, Professional Services Project Closing & Mapping $15, TOTAL $1,996, Sources of Funds Federal sources FEMA $1,497,375 Other federal sources $ State sources Local sources City $ County $499,125 Special district $ Private sources (In-kind) $ Other $ TOTAL $1,996,500

8 POTENTIAL FUTURE LOSSES Describe potential disaster impacts if not mitigated Asset / Service Description Value Description of Loss ( i.e. critical function, displacement, emergency access) Damages to homes within Tea Tributary Project area $4,477,934 Loss of function of homes, damages to homes within the project area Describe estimated quantifiable benefits: COST EFFECTIVENESS The Spring Creek Tributary drainage improvements area is projected to reduce damages to area homes by $4,477,934 over the life of the project. This figure was calculated by conducting FEMA s benefit cost analysis utilizing elevation and hydraulic studies. What is the expected life of the project? Project Benefits Project Costs 50 Years $4,477,934 (with maintenance included) $2,134,507 (with maintenance included) Federal Grant Share (75%) Applicant Grant Share (25%) $1,497,375 (without maintenance included) $499,125 (without maintenance included) Benefit- Cost Ratio (Must be greater than 1:1) 2.10 Did you use FEMA s BCA Model? Yes No - Attach a copy of the completed BCA to the application.

9 PROJECT SCHEDULE Milestones Activity / Action Project Administration Preliminary Design Environmental & Cultural Resources (Preliminary) Construction Design (Phase 1) Utility Relocation (Phase 1) Materials Acquisition Land Rights Acquisition Environmental & Cultural Resources (Phase 1) Construction Design (Phase 2) Utility Relocation (Phase 2) Construction Administration (Phase 1) Project Construction (Phase 1) Environmental & Cultural Resources (Phase 2) Construction Administration (Phase 2) Project Construction (Phase 2) Time (months, weeks, days) 1,095 Days 0 Days 90 Days 181 Days 182 Days 60 Days 182 Days 89 Days 180 Days 182 Days 182 Days 182 Days 89 Days 182 Days 182 Days How were starting and completion dates determined? The project time lines were determined by task and season. Please see the attached Gantt Chart. Maintenance Type Provider Date or Interval Cost Yearly 10,000

10 MITIGATION ALTERNATIVES Alternative Consequences 1. Do Nothing Repetitive and cumulative damages to homes, buildings, contents, personal property, septic systems, roads, and infrastructure with loss of access within the project area. 2. Option Two The project begins with a 100-acre ft pond upstream of Elmen Acres. This pond will require approximately 240,000 cubic yards of pond excavation. The excavation for this pond is estimated at a price of $960,000. The pond outlet will be a twin 4 x50 RCP with flared ends along with a weir overflow for large runoff events. The cost for the 4 x50 RCP with flared ends is estimated at $16,000 and the weir section will cost $12,000. There will be minimal channel increases upstream of SD Hwy 11. There are twin 48 x100 RCPs at the north crossing of SD Hwy 11, these RCPs will be replaced with a 100 double barrel 10 x6 precast concrete box culvert. This double barrel precast box culvert is estimated at a cost of $180,000. At the south crossing of SD Hwy 11 the existing 24 x78 RCP will be replaced with a twin 36 x78 RCP with flared end sections. These twin 36 x78 RCPs are estimated to cost $20,280. Cody Road will be lowered in order to lower the Base Flood Elevation (BFE) upstream of Cody Road. At Cody Road the single 6 x52 CMP will then need to be replaced with a 6 x52 Arch CMP at a cost of $13,000. To prevent overtopping in a 100-year event, the existing 3.5 x50 CMP at the east crossing of 85th Street (270th Street) will be replaced with twin 4 x50 RCPs with flared end sections at a cost of $16,000. The Spring Creek Tributary railroad-crossing embankment will be modified to create a no-rise in a 100-year event. Approximately 17 residences, outbuildings and personal property within the project area will not be impacted by the 100 year flood The proposed project passes the 100 yr flood event through subdivisions up to 270 th St, lowering the BFE below most homes. Severe or multiple runoff events may not be accommodated by existing downstream culverts It does not address the entire affected area and may not accommodate anticipated growth and sustainability within the developing watershed area

11 MITIGATION ALTERNATIVES 3. Proposed Option The project begins with minimal channel increases upstream of SD Hwy 11. The twin 48 x100 RCPs at the north crossing of SD Hwy 11 will be replaced with a 100 double barrel 12 x6 Reinforced Concrete Box Culvert (RCBC). This double barrel precast box culvert is estimated at a cost of $200,000. At the south crossing of SD Hwy 11 the existing 24 x78 RCP will be replaced with a twin 36 x78 RCP with flared end sections. The twin 36 x78 RCPs are estimated to cost $20,280. Just downstream of Hwy 11, a private driveway will be converted into a lowwater crossing, with twin 36 CMP to handle low flows. From just downstream of Hwy 11, downstream to 270th Street, capacity increases will be designed above and outside of the current streambed and bank in order to maintain or lower the Base Flood Elevation (BFE). At Cody Road the single 6 x52 CMP will be replaced with a 6 x52 Arch CMP at a cost of $13,000. A 7 x50 RCP with a flared end section will be added to the existing single 6 x50 CMP at the west crossing of 85th Street (270th Street) at a cost of $21,500. To prevent overtopping in a 100-year event, the existing 3.5 x50 CMP at the east crossing of 85th Street (270th Street) will be replaced with twin 4 x50 RCPs with flared end sections at a cost of $14,000. At the north crossing of Split Creek, the existing structure will be replaced with a double 12 x5 RCBC to lower the BFE in this area, and to prevent overtopping of the roadway during the 100- year event. The south crossing will have a 7 x70 CMP added to the existing twin 5 x70 CMPs at a cost of $16,800. Chateau Ct currently has twin 5 x144 CMPs where a 6 x144 CMP will be added at a cost of $30,240. The Spring Creek Tributary railroad-crossing embankment will be modified to achieve a no-rise in a 100-year event. On Spring Creek at Saddlerock Place, the existing twin 6 CMP will be replaced with a double 12 x9 RCBC. This will lower the BFE below the adjacent affected structure, and will also prevent overtopping of the roadway during the 100-year event. The end of the project will consist of raising the road at 479th to create storm water detention to mitigate the effects from the upsizing of the various pipes upstream on Spring Creek Tributary and Spring Creek. The outlet structure for this pond will utilize the existing double barrel RCBC, as well as a weir overtopping section for handling events greater than the 100-year event (roadway will function as the weir). This outlet will also include additional erosion protection measures to handle increased flows The 100 year flood plain will be lowered below structure lowest floor levels Approximately 20 residences, outbuildings and personal property within the project area will not be impacted by the 100 year flood Damages to infrastructure will be reduced Detention design will improve regional access during flood event Overtopping of roads will be eliminated on main access roads Designed improvements as a drainage system will addresses sustainability The proposed project passes the 100 yr flood event through all subdivisions, lowering the BFE below most residences and ensures access to affected areas. It will accommodate anticipated growth and sustainability within the developing watershed area

12 MITIGATION ALTERNATIVES Note: Alternative 2 should be a solution that would be acceptable if the proposed project could not be realized. Why does the proposed project seem to be the best solution? Through the affected area, culverts and road structures determine the elevations of the flowing water. In order to lower flood water elevations the capacity to pass these flows must be increased or the waters entering the system must be decreased. Detention of increased flood volumes in normally dry ponds designed to hold and meter discharges can decrease the input to the system or slow discharges at the end of the system. Culverts may be increased in size and roadways may be lowered to allow the water to overflow to achieve lowered water elevations. In cases where roads provide the only access to residences the culverts must be enlarged to prevent overtopping. Detention needs were found to be the controlling factor for making improvements. The best project was derived from hydrologic modeling and cost estimates for three detention options: 1. Detain the 100yr event input to the project area to levels below the first floor levels of residences without channel or culvert increases 2. Detain the 100yr event input to the project area to levels below the first floor levels of residences with culvert increases at both Elmen Acres outlets under Hwy 11. This to be done sufficiently to dissipate additional discharge volumes by 270 th St. This option requires only minimum channel increases and allows for culvert increases at both Elmen Acres outlets under Hwy Detain the 100yr event discharge from the project area to pre-project volumes with increases and additions to culvert sizes and channel capacities throughout the project area ( See attached series of maps used to determine these options) Criteria considered in evaluating these options included: 1. Ability to pass the 100 year event 5. Ability to lower the BFE 2. Detention requirements 6. Sustainability and maintenance 3. Ability to assure access to homes 7. Cost 4. Environmental concerns 8. Downstream impacts Option 1 was eliminated due to the following: 1. Does not ensure protection from ponding and backup since it does not pass the 100 year event 2. Cost of excavation and land are cost prohibitive 3. Downstream impacts could remain in severe or multiple runoff events Option 2 was eliminated due to the following: 1. Does not ensure the ability to pass a 100 year event through the entire system 2. Cost of excavation and land high without benefit for entire system 3. Downstream impacts could remain in severe or multiple runoff events Option 3 was selected due to the following: 1. Culvert and channel increases ensure the ability to pass a 100 year event through the entire system 2. Detention costs improve regional access route 3. Downstream impacts are mitigated to assure access to homes 4. Provides a comprehensive system accommodating severe or multiple runoff events and lowers BFE 5. Addresses sustainability with designed improvements as a drainage system In Summary: The proposed project passes the 100 yr flood event through all subdivisions, lowering the BFE below most residences and ensures access to affected areas. It will accommodate anticipated growth and sustainability within the developing watershed area.

13 Describe how the proposed project was selected? MITIGATION ALTERNATIVES The primary objective was to prevent flood water from impacting the Elmen Acres basin area. The most suitable option to effectively mitigate flood damages at Elmen Acres is to eliminate the potential threat of ponding and backup by enlarging the culverts at Hwy 11 to pass the 100 year event. Additional discharges from enlarged culverts were modeled and calculated to evaluate a base project with detention at 270 th St. The anticipated detention area capacity was found to be insufficient thus expanding the study area. Detention locations were explored and additional mitigations throughout the affected area were taken into account. Options included; excavation, increasing culvert sizes, adding additional culverts, lowering road surfaces, allowing overtopping of roads, building alternate routes for access, removing roads, acquisition and retrofitting homes by dry flood proofing or berms. Three alternatives for detention were chosen to be studied for hydrology. Costs were developed to determine feasibility. County staff reviewed variables to study and develop. Options were derived from the study findings and cost estimates. The proposed best project was selected after reviewing the study and prioritizing the options by costs and benefits. Meetings were held throughout the project development process with local property owners with regards to the proposed base project developments. Periodic staff review included Planning and Zoning, Geographic Information Services, Emergency Management, the States Attorney, and the Lincoln County Commission. Public meetings were held on April 19, 2011, May 18, 2011, June 2, 2011, and July 28, 2011 to identify potential projects and find solutions to the flood hazard. It is the general opinion of the property owners within the project area that something needs to be to done in order to address long-term flooding impacts. Currently some homeowners are retrofitting with berms to protect against the present threat of flooding.

14 PROJECT COMPLIANCE ASSURANCES Building Code Does the government jurisdiction where the project will be located currently enforce the 1991 (or later) edition of the Uniform Building Code, including seismic chapters? Yes No If NO, give date when the current edition (1997) will be adopted and attach evidence of intent to adopt and enforce it. Land Use and Zoning Will the project meet all land-use and zoning codes and standards for the local jurisdiction? Yes No National Flood Insurance Program Is the government jurisdiction where the project will be located participating in the NFIP? Yes No - If NO, give date when the program will be adopted and attach evidence of intent to adopt and enforce an appropriate floodplain ordinance. If YES, are they in good standing? Yes No - If not in good standing, attach an explanation Is this project located in a floodplain or floodway designated on a FEMA Flood Insurance Rate Map (FIRM)? Yes No If YES, provide FIRM Panel Number 46083C0157C FIRM Zone Designation AE NFIP Community ID Number Public Notification Have there been any public notices or public meetings about this project and the problems it seeks to solve? Yes No Local Hazard Mitigation Plan Does the local government where the project will be located have a FEMA approved all-hazards mitigation plan that identifies natural hazards and lists specific plans that reduce the impact of the hazards on life and property? Yes No The hazard mitigation plan is in the process of being updated for Lincoln County. Is the proposed project identified in your plan? Yes No The proposed project is listed in the hazard mitigation plan update.

15 PROJECT COMPLIANCE ASSURANCES SIGNATURE OF AUTHORIZED AGENT: The undersigned does hereby submit this application for financial assistance in accordance with the Federal Emergency Management Agency s Hazard Mitigation Grant Program and the State Hazard Mitigation Administrative Plan and certifies that the applicant (i.e., organization, city, or county) will fulfill all requirements of the program as contained in the program guidelines and that all information contained herein is true and correct to the best of our knowledge. Signature: Date: Title: WHEN COMPLETED, THIS APPLICATION ALONG WITH A DETAILED SCOPE OF WORK AND BENEFIT COST ANAYLSIS SHOULD BE RETURNED TO: South Dakota Office of Emergency Management State Hazard Mitigation Officer 118 W. Capitol Ave Pierre, SD

16 RESOLUTION APPOINTMENT OF APPLICANT AGENT FOR THE HAZARD MITIGATION GRANT PROGRAM (HMGP) WHEREAS, is submitting a Hazard Mitigation Grant project to the Federal Emergency Management Agency and the State of South Dakota; and WHEREAS, is required to appoint an Applicant Agent for the purpose of signing documents and assuring the completion of all application documents; NOW THEREFORE BE IT RESOLVED that appoints as the authorized Applicant Agent. Dated this day of, 200. Appointing Authority Name: Title: Signed Date Appointed Agent Name: Title: Signed Date