You can’t build your way out of flooding problems: SC report comes up short | Opinion
Ever-increasing numbers of South Carolinians are at risk for flooding impacts.
S.C. conservationists were encouraged when Gov. Henry McMaster created the Floodwater Commission to identify solutions for our flooding problems.
The Senior Conservation Leadership Alliance, an organization of retired environmental scientists, reviewed the Floodwater Commission’s final report. Below we highlight our findings.
It is unfortunate that the commission’s final report does not distinguish between coastal and inland flooding. Coastal systems experience flooding from storm surge, tides and rising sea level, and increases in stormwater runoff following rain events.
The most severe coastal flooding occurs when stormwater runoff intensifies concurrently with storm surge and the persistently higher tides related to sea level rise (e.g., Charleston peninsula). Flooding in inland areas occurs when the volume of runoff from rain events overruns the banks of rivers, streams and reservoirs and exceeds the capacity of the floodplains and drainage infrastructure to contain it.
Statements in the commission’s report emphasizing low-impact development and stewardship of natural resources are encouraging.
Unfortunately, most of the commission’s recommendations align more with costly and impractical engineering solutions to flooding.
The absence of flood prevention recommendations (e.g., less impervious surface, no fill-to-build, minimizing stormwater runoff) is disturbing.
The protection of wetlands is crucial since isolated wetlands and headwater streams are no longer protected under the Clean Water Act.
In addition, the commission’s recommendations that promote river channelization and construction of large, new reservoirs conflict with recommendations elsewhere in the report supporting wetland and floodplain protection. River channelization and reservoir creation destroy natural flood control systems, exacerbate flooding of downstream communities, and destroys shallow-water habitat that supports fishery resources.
We applaud the commission’s recommendations supporting amendments to the State Code of Laws requiring flooding risk and sea level rise to be elements of the comprehensive land planning process.
However, land use guidance that minimizes the volume as well as rate of stormwater runoff from new and existing sources must also be included in the Code of Laws.
This guidance should emphasize conservation of wetlands, development of land-use plans at the watershed scale, and prediction and management of the cumulative effects of flooding from all potential sources.
The commission unwisely recommends evaluation of nearshore artificial reefs to protect ocean shorelines. Artificial reefs may somewhat abate storm surge but will do nothing to mitigate flooding. The suggested artificial reef research would take decades to implement and construction of artificial reefs close enough to shore to reduce storm surge would likely impair sediment transport processes and enhance long-shore beach erosion.
We, however, support the commission’s recommendation to use living shorelines to mitigate estuarine shoreline erosion and increase marsh resilience to sea level rise and storm surge.
The commission’s report does not include an implementation plan. There is no prioritization of what should be done first and little consideration of the cost, complexity, time frame and organizations responsible for implementing recommendations. No sources of funding other than federal sources are identified.
State and local funding resources need exploration and development. We suggest that when state tax revenues exceed normal budget needs, a portion of those revenues be retained as a state match for emergency federal funds following future flooding disasters.
The commission’s stakeholder engagement recommendations lack specificity.
The commission should work with Clemson Extension Service, S.C. Sea Grant Consortium, flooding experts, and other relevant organizations to develop region-specific education and outreach materials and workshops that: identify the causes of flooding, define its impacts, and identify solutions.
Then, the commission can convene regional workshops targeting teachers, the public, county and city planners, community organizations, the governor and state legislature, and state agencies.
Finally, climate change and sea level rise are major factors influencing flooding along our coast. The Floodwater Commission is mainly silent on these issues and their influence.
Prepared for the Senior Conservation Leadership Alliance by Fred Holland, Rick Dawson, David Whitaker and Steve Gilbert.