9/14/2012. Floodplain Basics the 100 year Flood. Columbus & Bartholomew County Flood Regulation Study Committee. Bartholomew County Floodplains

Transcription

1 Floodplain Basics the 100 year Flood Columbus & Bartholomew County Flood Regulation Study Committee 100-year Floodplain Purdue Land Use Team Video Seminar Series September 17, 2012 Floodway 1.2 inches Flood Fringe City of Columbus Bartholomew County Planning Department City of Columbus Bartholomew County Edinburgh / Bartholomew / Columbus Joint District Town of Hartsville Bartholomew County Floodplains Bartholomew County Floodplains Mapped Floodway US 31 I 65 SR 9 Flat Rock River 100 year Floodplain Hope Haw Creek 500 year Floodplain I 65 Significant Highway Hartsville Driftwood River Columbus Clifty Creek SR 46 SR 46 SR 46 US 31 SR 7 I 65 US 31 Denois Creek SR 58 SR 11 SR 11 White River 1

2 Past Floodplain Management & Regulation Approach Cummins Tech Center Floodways are to be avoided (due to flood risk + lengthy approval process). Flood fringe areas play a key role in Columbus growth and development; specifically for commercial and industrial sites (because of their geographic locations and land area coverage). Floodplain regulations follow the minimum FEMA / IDNR requirements (with some minor additions, i.e.: building protection also required in the 500 year floodplain). Floodplain regulations generally perceived as a nuisance by developers, home owners, etc. This property has never flooded! / How can I avoid paying flood insurance? Columbus Regional Hospital Columbus Regional Hospital Office Building 2

3 First Financial Bank Eastbrook The Flood of June 7, deaths. +/ 3,000 homes damaged or destroyed. $500,000,000+ in property damage. Damaged structures include: Columbus Regional Hospital (closed 6 months for repairs). Cummins Columbus Tech. Center, Engine Plant #1 and Child Care Center Columbus East High School Bartholomew County REMC Offices/Shop Mariah Foods Facility Cummins Engine Plant #1 and Tech. Center Columbus Regional Hospital 3

4 Columbus East High School (Clifty Creek) Columbus East High School (Clifty Creek) City County Flood Regulation Study Committee Formed: August of 2011 as part of an ongoing community discussion of floodplain issues. Task: Research options for regulating development in local floodplains, collect public input, and identify recommended regulatory changes. Membership: 17 members including 9 elected or appointed officials and 8 citizens. Plan Commission members Soil & Water Conservation District representative Columbus City Council member Bartholomew County Commissioner Farm Bureau representative Citizen volunteers submitted letters of interest and were selected by the Plan Commissions Noblitt Falls Neighborhood (Flat Rock River) 4

5 City County Flood Regulation Study Committee 11 Committee Meetings (between Aug and Sept. 2012) Mtg. #1 organize committee and generally discuss options Mtg. #2 IDNR and Christopher B. Burke Engineering, LLC presentations Mtg. #3 review of initial public input Mtg. #4 Economic Development Board presentation Mtg. #5 Indiana State Climatologist presentation Mtg. #6 Emergency Management presentation Mtg. #7 environmental concerns presentation Mtg. #8 & #9 options discussion Mtg. #10 finalize draft recommendations Mtg. #11 review public comments and create final recommendations Interviews with Surrounding Communities (with which Bartholomew County shares watersheds). 2 Public Input Periods (public open house event & on line survey) Climate Presentation Take aways Climate refers to weather patterns over several decades or longer time period. The parameters for evaluating weather events are not stationary; they are evolving. La Nina and El Nino are significant, normal patterns that affect weather. La Nina years are known for severe weather and heavy spring rains in the Midwest. Weather events or patterns that are not explainable by typical changing seasons or known climate patterns may be indicators of something else perhaps climate change. Climate Presentation Take aways Committee Recommendations Regulations Rainfall amounts in the Midwest have increased over time. Indiana rainfall amounts have changed. There is an increase in the number of days with measurable rainfall and the number of days with moderately heavy rainfall (1 to 3 inches). There is an increase in the variability of rainfall events (more rain in a single event, for example). The long term climate projection models show more rain longterm in Indiana and the rest of the Midwest. At the local level we should expect extremes. Local communities should not plan for the average condition because weather events are trending beyond the average and are instead on the edge of known possibilities. Each community must decide how much risk is acceptable. 1. Continue local regulation of the 500 year floodplain (vs. the 100 year floodplain emphasized by FEMA / IDNR). 2. Prohibit new development in the floodway of all streams. 3. Prohibit new critical and especially flood sensitive facilities from locating in the 500 year floodplain (nursing homes, animal shelters, day care centers, hospitals, schools, etc.). 4. Provide additional case by case scrutiny for facilities that are potentially harmful to water quality and/or public health as a result of flooding in the 500 year floodplain (confined animal feeding facilities, sewage treatment plant, commercial dry cleaners, etc.). 5. Support the continued viability of existing, grandfathered floodplain structures by reducing limitations on their expansion and repair. 5

6 Committee Recommendations Regulations Committee Recommendations Other 500-year Floodplain 100-year Floodplain 1. Take a proactive role in encouraging and supporting FEMA s update of floodplain maps to address specific known or suspected errors. 2. Prioritize minimizing impact on flooding as a criteria in bridge design. Floodway 1.2 inches Flood Fringe Other Efforts Supplemental Haw Creek Regulations Other Efforts Columbus Flood Risk Management Plan 1. Regulations for New Development* (floodplain development and land use, stormwater runoff, etc.) 2. Flooding Mitigation Projects (levees, retention ponds, stream maintenance, etc.) 3. Flood Emergency Management (flood warning system, evacuation plans, damage assessment, etc.) 1. Expands the area considered to be in the floodplain. * Will include recommendations and input from the Columbus & Bartholomew County Flood Regulation Study Committee. 2. Requires modeling of any development proposed in identified flow conveyance paths. 6

7 Other Efforts Columbus Flood Risk Management Plan Other Efforts Columbus Flood Risk Management Plan Flatrock River Haw Creek Sloan Branch Project Cost: $171,400 Project Consultant: Christopher B. Burke Engineering Project Timeframe: Scheduled Completion in May 2013 Driftwood River White River Denois Creek Opossum Creek Clifty Creek Key City Involvement: Planning, Engineering, and Fire Departments Public Participation: Opportunities for public comments on draft materials will be provided in March Noteworthy Outcome Expected: Initial development of a flood warning system that links National Weather Service rainfall forecasts, runoff projections, local stream gauges, flood depth maps, and local emergency responders. Questions? 7