The County has completed the preparation of a Stormwater Master Plan (SWMP) in support of the development of a Stormwater Management Program (SMP) for the unincorporated areas of Alachua County. This effort was undertaken to assist in meeting the Goals of the Stormwater Element of the County’s Comprehensive Plan. This master planning process was initiated in September 2007 and was completed in March 2010 by Inwood Consulting Engineers, Inc. under contract to Alachua County Public Works Department. Input into the SWMP was also provided by the Alachua County Environmental Protection Department.
The master planning process began with a collection of data relevant to stormwater within the County. This collection of data included physical characteristics, hydrology, topography, an inventory and conditions assessment of major drainage facilities and information on current flooding and water quality problem areas. This collection of data was then used to develop a Preliminary County-Wide Hydrologic and Hydraulic Model (H&H Model) to qualitatively evaluate the performance of the County’s major drainage conveyance and storage ways to identify deficiencies which represent needs warranting corrective action. In addition, this model provides a base data set that in the future can be built upon and refined for the purposes of the design of development projects, the preparation of more detailed stormwater retrofit projects, floodplain analyses, and water quality improvement projects to address stormwater management deficiencies.
In addition to developing a Preliminary County-Wide Hydrologic and Hydraulic Model, the SWMP also identified the causes and conceptual fixes for 18 major flooding locations in the County. Costs for these conceptual fixes were also developed and these projects were ranked based on the Federal Emergency Management Agency (FEMA) Benefit-Cost Analysis Methodology. The SWMP also identified several stormwater ponds and drainage easements that needed improvements to increase the water quality treatment.
The master planning process continued with quantitatively identifying the County’s other needs to provide a proactive SMP. The needs and costs for the following were identified in the SWMP: maintenance operations including staffing & equipment, administration including staff to address program administration, expenses associated with public education, regulation and code development support, inspection and enforcement support, National Pollutant Discharge Elimination System (NPDES) administration, Basin Management Action Plans (BMAP) support, program updates, and watershed studies.
The master planning process provided an opportunity to assess the state of stormwater management in the County, focusing on identifying needs to address flooding problems, water quality deficiencies, maintenance of drainage systems, and compliance with regulatory requirements. The SWMP showed that 70% of the inventoried stormwater features and structures did not meet current compliance standards and provided an opportunity to evaluate 18 major flooding locations within the County, showing the potential adverse impacts to infrastructure in these locations during a major storm event. In addition, the SWMP also identified 19 stormwater basins and 12 County maintained roads where immediate water quality improvements are required to meet current regulatory requirements. The SWPM also showed that there is a need for additional staff and equipment to provide a proactive maintenance program to address drainage related problems in the County. A Public Education Program dedicated to stormwater management was also recommended in the SWMP. Funding alternatives, external funding options, and recommendations for SMP implementation were also discussed in the SWMP. For each element, budget requirements were projected over a 10 year SMP planning period starting in fiscal year 2011. Based on the results of the SWMP, the average annual estimated SMP cost is on the order of $6,108,648 per year including all recommended program elements.