Stormwater Management (SWM)
2011 August 29– HMGP 1858-0013 amended to include t more homes in Unincorporated Cobb County within the effective 100-year (baseflood) floodplain which sustained “substantial damage” as the result of the September 21, 2009 flood.
2011 July 31– Construction of the Chastain Meadows Regional Stormwater Management Facility completed.
2011 May 1– Construction of Mark Avenue Regional Stormwater Management Facility begins.
2010 October 6– Property Acquisition Grant under Hazard Mitigation Grant Program (HMGP) 1858-0014 awarded to Cobb County and executed for the purchased demolition and removal of 16 residential homes in the City of Powder Springs within the effective 100-year (baseflood) floodplain which sustained “substantial damage” as the result of the September 21, 2009 flood.
2010 October 6– Property Acquisition Grant under Hazard Mitigation Grant Program (HMGP) 1858-0013 awarded to Cobb County and executed for the purchased demolition and removal of 34 residential homes in Unincorporated Cobb County within the effective 100-year (baseflood) floodplain which sustained “substantial damage” as the result of the September 21, 2009 flood.
2010 March 10- Construction on the Chastain Meadows Regional Stormwater Management Facility begins.
2009 November 13– Public Partnership Agreement with the Mobile District signed with the U.S. Army Corps of Engineers Mobile District
2009 September 21– Catastrophic flooding in Cobb County in which some 1600 homes were flooded countywide. Close to 100 homes in Unincorporated Cobb; over 84 homes in the City of Austell and over 16 homes in the City of Powder Springs sustained “substantial damage” . Southwestern portions of the county in and around the City of Austell at the Paulding – Douglas – Cobb County line received rainfalls in excess of 20 inches within a 24 hour period. USGS estimated this storm was well above the 500 year recurrence interval. NWS straight-line projections put this storm at the 10,000 year recurrence interval.
2008 September 26- Final Design Place, Specifications, and Geotechnical Report for the Chastain Meadows Regional Stormwater Management Facility resubmitted to Georgia Environmental Protection Division (GAEPD) for approval.
2007 November 28- Digital Flood Insurance Rate Maps (DFIRM) Drafts for Cobb County Update submitted to Federal Emergency Management Agency (FEMA). DFIRM scheduled to become effective on December 21, 2008.
2007 September 26- Design Plans and Specifications of Chastain Meadows Regional Stormwater Management Facility resubmitted to Georgia Environmental Protection Division (GAEPD) for approval.
2007 August- Pilot study completed for Storm Drainage Structure Inventory, Northeast Cobb County.
2006 April 6- Georgia Emergency Management Agency (GEMA) flood mitigation assistance grant number FMA-PJ-04-GA-FY2006-007 awarded to Cobb County for the buyout of 1 home on Rio Montana Drive
2006 November 6- Stream Buffer Variance received from Georgia Environmental Protection Division (GAEPD) for Chastain Meadows and Mark Avenue Regional Stormwater Management Facilities (Noonday Creek Watershed).
2006 October 27- Georgia Emergency Management Agency (GEMA) flood mitigation assistance grant number FMA-PJ-04-GA-FY2006-006 awarded to Cobb County for the buyout of 2 homes on Rio Montana Drive.
2006 April 6- District Authorization for Section 404 Individual Permits for Chastain Meadows and Mark Avenue Regional Stormwater Management Facilities (Noonday Creek Watershed).
2005 July 11- Hurricane Dennis hits Cobb County and drops 12–14 inches of rainfall in southwestern Cobb County. Approximately 400 properties were flooded and over 70 homes were damaged. Two Georgia Emergency Management Agency (GEMA) Flood Hazard Mitigation grants were obtained to buy-out 26 homes which sustained “substantial damage”.
2004 September 7- Hurricane Francis. Received Federal Disaster Declaration. Minimal flooding to Cobb County.
2004 September 16- Hurricane Ivan causes widespread flooding in central and northeast Cobb County. Flooding of numerous roads in Cobb County after dropping 4 -8 inches of rainfall in Cobb County over a 2 hour period.
2004 September 28- Hurricane Jean brushes by Cobb County causing minor flooding.
2004 Jordan Jones and Goulding Inc. submits updated Hydrologic and Hydraulic Modeling Results for “Priority Area 4” (PA4) which includes: Sope Creek, Sewell Mill Creek, Rubes Creek, and Trickum Creek watersheds.
2004 AMEC Inc. submits updated Hydrologic and Hydraulic Modeling Results for “Priority Area 3” (PA3) which includes: Nickajack Creek, Rottenwood Creek, and Olley Creek Watersheds.
2003 Receipt of two 75/25 matching Georgia Emergency Management Agency (GEMA) grants, Cobb County Water System is able to buy out (and move out) a record number (45) floodplain homes, including homes along areas of chronic flooding on Leasa Court and on Cynthia Court.
2003 AMEC Inc. retained to evaluate current level and extent of stormwater management services offered in Cobb County and whether a compelling case exists (created by state and/or federal government mandates; changing legal precedents or increasing citizen demands) to augment (or curtail) the current level of stormwater management services.
2001 Cobb County’s enhanced Stream Buffer Ordinance revised to require restrictive easements is recorded for all enhanced stream buffers within new developments.
2001 June 28- A series of three concentrated thunderstorms pass over northeast Cobb County in rapid succession dumping almost 4 inches of rainfall within a 2 hour period of time resulting in the flooding of 34 homes in the vicinity of Trickum and Steinhauer Roads.
2001 Kucera Inc. completes two foot contour interval digital mapping for the entire county.
2000 October 10- The Disaster Mitigation Act of 2000 (DMA 2000) was put into motion. President signs the Act (Public Law 106-390). This legislation reinforces the importance of mitigation planning and emphasizes planning for disasters before they occur. As such, the Act establishes a pre-disaster hazard mitigation program and new requirements for the national post-disaster Hazard Mitigation Grant Program (HMGP).
2000 Cobb County Board of Commissioners approved limiting impervious surface coverage in Regional Activity Centers (80% for commercial, 70% for residential, 70% for Community Activity Centers, and 70% for Neighborhood Activity Centers) where the property contains one or more streams or floodplains. Streams and floodplains must be identified as open space.
1999 October 1- Enhanced stream buffer ordinance goes into effect. Minimum stream buffer width is now 50 feet. Buffer widths increase up to 200 feet, depending upon drainage intercepted and the stream involved.
1999 Cobb County Board of Commissioners enact an Open Space Community (“OSC”) Zoning overlay district to encourage the set aside of Flood Hazard Areas as open space not to be developed. The OSC Overlay District ( Cobb County Code §134-198.1) is designed to protect land and water by limiting land disturbance, decreasing impervious surfaces and permanently protecting contiguous open space in perpetuity via mandatory covenants.
1999 Cobb County Board of Commissioners approves Countywide Watershed Assessment and Protection Plan Program.
1999 June 30- A concentrated thunderstorm stalls near the City of Powder Springs dumps some 5 inches of rainfall over a 2 hour period, resulting in the flooding of 144 homes.
1999 April- Mayes Sudderth and Etheredge Inc. and Parsons E/S Inc. submit Final Report for “Priority Area 2” (PA2) which includes: Allatoona Creek, Little Allatoona Creek, Butler Creek, Proctor Creek, and Tanyard Creek watersheds. Recommended Plan as proposed in this study cannot be implemented due to the presence of an endangered species, the Cherokee Snail Darter, on Proctor, Butler and Allatoona Creeks.
1998 Greenhorne and O’Mara Inc. submit the Recommended Plan for “Priority Area 1” (PA1) drainage basins to the Cobb County Board of Commissioners. PA1 includes Noonday Creek, Noses Creek, Mud Creek, John Ward Creek, and Powder Springs Creek watersheds.
1997 The Cobb County Development Standards completely revised for the first time since the early 1980’s. Significant upgrading of floodplain protection elements included dam design regulations.
1994 Stormwater Management Division implements Unit Price Contract Program. Program is initially funded with an annual budget of $1.6 million thereafter to increase 20% per year for five years.
1993 Stormwater Management Division Transferred from Community Development Agency to the Cobb County Water System.
1992 August 18- The Cobb County Flood Insurance Study is reissued. Restudies of the hydrology for: Noonday Creek, Little Noonday Creek, Morgan Lake Tributary, Noonday Creek Tributary 3, Noonday Creek Tributary 4, Rubes Creek, Trickum Creek, Olley Creek, and upper reach of Rottenwood Creek were performed. Previous floodplain analyses for the other streams studied in Cobb County were copied onto this flood insurance study update.
1989 July 6 & 7- Torrential thunderstorm stalls over northeast Cobb dumping 9 inches of rainfall in 13 hours over portions of Cobb County (Tate Creek, Noonday Creek, Trickum Creek, and Rubes Creek watersheds). Several roads flood. Wooten Lake Road washes out. Significant damage to Wooten Lake Dam occurs, but Cobb County’s Regional Flood Control facility located immediately downstream on Tate Creek, survives with minimal damage. Emergency spillways at the SCS watershed control structures at Frey Lake and at Burruss Lake both engage. Extrapolations on probability paper place this storm to be almost a 1500-year recurrence interval flooding event.
1989 Congress enacts George C. Bush’s “No Net Loss in Wetlands” policy.
1989 February- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1988 October 11- Cobb County’s Flood Damage Prevention Ordinance revised per Federal Emergency Management Agency (FEMA) guidelines.
1988 March- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1987 October- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1986 July 21- Final Report, “Cobb County Drainage Study”, submitted to David Hankerson by Connelly Sanders, Jr., P.E.
1986 April- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1982 Using Federal Emergency Management Agency (FEMA) funds, Cobb County Water System purchased and removed 14 homes along Sope Creek which had suffered repeated flooding.
1980 Cobb County’s population rises to 297,718 persons.
1979 December 11- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1978 October 1978- “Section A, Requirements for Plan Review for Cobb County” REVISED.
1978 Federal Emergency Management Agency (FEMA) issues the first Flood Insurance Study for Cobb County, which include Flood Insurance Rate Maps (FIRMs), and Floodway - Flood Hazard Boundary Maps. Prior to the issuance of these maps, property owners in Cobb County could utilize the United States Department of Agriculture's (USDA) SCS Soils Maps and the U.S. Housing and Urban Development’s Preliminary Flood Hazard Maps to get a rough idea about flood hazard potential for their respective properties.
1975 July 28- "Section A, Requirements for Plan Review for Cobb County” AMENDED.
1975 Georgia Sediment and Erosion Control Act enacted.
1974 March 6- “Section A, Requirements for Plan Review for Cobb County” AMENDED.
1974 November 12- “Section A, Requirements for Plan Review for Cobb County” ISSUED.
1972 Congress Enacts the United States Clean Water Act (USCWA).
1968 Congress authorizes the Federal Flood Control Act which ultimately leads to the creation of the National Flood Insurance Program (NFIP).