Dune Hugger: Erosion Response Plan

By ROB NIXON

Special to the PRESS

On December 15, Cameron County, PAR Consulting and Applied Coastal Research and Consulting held their second public forum on the new Cameron County Erosion Response Plan (ERP).  As I have mentioned before, the purpose of the state mandating Counties and Cities to come up with ERPs is to reduce the public expenditure risk of developing, protecting and bailing out coastal development along Texas’ 365 mile long coastline.  While the first meeting was an overview of what the ERP wanted to accomplish and the timeframe in which it would be achieved, this forum focused specifically on what the Consulting Team’s building setback recommendations.  This, in my opinion is the essential core of the ERP as a building setback line provides space to preserve and enhance established dunes, protect the public beach easement and to give the beach room to breathe.  The lack of a real building setback line was one of the fatal flaws of the original County Plan that was rejected by the Texas General Land Office.

What are the nuts and bolts of the new building setback proposal and how will Cameron County manage the sand?

First off, the baseline seaward boundary of the building setback line will be the mean high tide line.  The MHT is the average high tides in that area over a 19 year period.  This would be the beginning of the “Dune Conservation Zone” in the plan.  The landward boundary of the Dune Conservation Zone would be 300 feet landward of mean high.  To arrive at this number, the consultants took the average erosion rate over the beaches they are planning for north of the City of South Padre Island, 10 feet annually, and multiplied it by 30 years— a standard mortgage.  Sand locked within the dunes landward of the Dune Conservation Zone would be then redistributed to low spots within the Dune Conservation Zone and vegetated in order to create a continuous dune line that would be a minimum of 100 feet wide with many areas being much wider.  The height of the dunes is still up for review but loosely proposed at 12-13 feet.  This potentially also allows for the “topping” or lowering of higher dunes within the Dune Zone.

The program of relocation of material would be carried out in phases and not piecemeal along this stretch of coast.  Instead of doing this project by project, sections of 1,000 feet or so would be worked on at a time until the project is completed.  This would secure uniformity in the management plan and grow and help mend dunes in large sections and not in small sections at a time.

So why concentrate on the dunes first and not just jump to beach renourishment to hold the line?  The simple answer is money and access to resources.  Between 2000 and 2013 the beaches here have accumulated millions of cubic yards of sand.  The sand is already there to be utilized.  Offshore sand sources will take time to research, search for and capture while costing much more.

The issue with the plan that still needs to be identified are the lots that will fall within the Dune Conservation zone that will not be allowed to develop.  An acquisition plan must be formulated to deal with this issue.  This will be complicated and require some political will from the Cameron County Commissioners for sure.

Overall, this is a much better plan than the original ERP that the GLO rejected in 2012.  However, there are still concerns that I have such as the topping of dunes, how will dune plants be preserved and transferred from the construction area to the Dune Conservation Zone and is the Building Setback Line static or will it be dynamic?  A static line will give the projects uniformity while a dynamic line will allow the beach to migrate.  Right now the beach is rapidly migrating landward.  A dynamic line would allow for the beach to continue this.  The negative of a dynamic line would be if the county is actually successful through other management practices such as beach nourishment to actually overcome the erosion rates, move beyond just shoreline stabilization and start accreting the beaches, doubtful in my opinion, would they then consider relaxing their setback lines.  All questions to ponder as we move forward in this process.

The next ERP meeting will be in February and all material from previous meeting can be found at the website at www.CameronCountyERP.com.  You can also leave your comments in their forum there as well.

Want the whole story? Pick up a copy of the Port Isabel-South Padre Press, or subscribe to our E-Edition by clicking here.

Permanent link to this article: https://www.portisabelsouthpadre.com/2015/12/18/dune-hugger-erosion-response-plan-3/

Leave a Reply

Your email address will not be published.

 

This site uses Akismet to reduce spam. Learn how your comment data is processed.