Drainage plan for a beach community

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A Property Owners Association in Florida on the East coast of the US has major drainage issues. There are over 1200 units located directly on/near the beach. They have a golf course with five ponds. Many areas flood often with only a few înches of rain.

They need to address this in stages and are looking for approaches or samples of RFPs to request proposals to develop and implement in stages a drainage plan. 

One of the many questions is whether there is an open access map data available that would show elevation.

Feedback much appreciated as to the best process to create a biddable document that focusses on primary issues and includes what data the community needs to provide in order to get good bids. 

Your feedback much appreciated

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12 Answers

  1. As previously stated, any solution will require an engineer and geologist as part of the solution.   That said, to answer your question directly, we provide aerial drone-derived data to the engineers and geologists in the form of 3D digital terrain models at very high precision.   From These we do a simple watershed and surface flow analysis to help them assess rain events and where that short-term water goes.  Remote-intelligence.com

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  2. Without knowing the specifics, I'd speculate that the existing drainage system and golf course ponds are being tailwater controlled by tidally-influenced groundwater levels. Rainfall events coinciding with high tides are becoming increasingly problematic along the east coast of Florida. Creating additional storage or detention areas, such as wetlands, will really only be beneficial if there is the ability to place them above the groundwater table, otherwise most of the storage will already be filled when the storm occurs. Vaults that are normally dry and isolated from the water table may provide some relief, but may be costly. 

    In terms of bid documents, any competent engineering firm that does drainage design can round up the information needed. I don't think the owners need to compile that information. As it appears to be a private organization, their purchasing rules may not require bids. I'd start with their board reaching out to local engineering consultants to see if they can have a few come out and look at the problem and then have them develop proposals to hopefully make things better. I'd proceed incrementally: have an engineer clearly identify the cause; develop several alternative solutions; and then implement the preferred solution. 

  3. Typically, this work is all accomplished through an engineering consulting firm in some form of initial study where alternatives are identified and preliminary cost estimates generated.  Costs for an initial study are often relatively modest. The POA could "go it alone" initially but, ultimately and prior to construction work of any kind, they would need to involve a PE.  Recommend looking for a local firm that specializes in site work or storm water management.  The local government entity responsible for SWM would probably be able to proved a list of firms that they have worked with or have a pre-approved list (they might even let you know the companies that are the best to work with).  The POA should set up a subcommittee to oversee the process and report to the POA board.  The subcommittee would interview prospective engineering consultants, evaluate fee schedules and recommend a selection to the board.  The selected engineering firm should be able to lead the subcommittee and the board through further steps in the process of ultimately addressing the issue.  During initial interviews, I would personally ask any consulting firm how they address climate change issues in their designs and recommendations, especially in a coastal community.

  4. For open access data on elevations and boundary info you might try    Labins.org

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    1. thanks, it looks promising but i could not figure out how to get sea level elevation map of our parcel at 2400 south ocean drive in fort pierce fla 34949. could you help?

  5. IMO: use/create linked wetland systems that are bermed for holding, treating and slowly releasing the stormwater.

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    1. what process would you suggest to quickly evaluate the options to determine that this would be the best solution? Since so close to the ocean does it make sense to add pumping back into the ocean or because they have many areas under sea level it that useless?

  6. I worked in the 2019 flood in Khuzestan province in southwestern Iran.

     I presented 60 geological, hydrological and geomorphological solutions to the officials, which were often considered and implemented. If you see my resume, I mentioned it there.

    However, for your project and site, we must visit the site area or know the geology and geomorphology of the area in order to provide a suitable solution.

    If you wish, I will translate a part of the report and send it to you.

    Of course, the proposed solutions in this report are specific to this region and each region has a different topography.

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    1. Thank you Alireza, if you believe there are parts of the report that might help please do translate and post here for everyone behalf

       

      1 Comment reply

      1. I want to send you an article about floods. So I need your email address. Thanks

  7. As suggested by many, site inspection of the existing drainage facility is foremost to understand the current situation.  Secondly, one needs to check for the blockages and the reasons for it.  Although plastics has been banned, there could be a possibility of them blocking the drainage (that is normally the problem in many cities even in Bangalore where I reside). Once this is done, it is important to evaluate whether the existing width is fine or need further widening; secondly, whether a separate drainage is to be designed for the golf where there is canteen waste coming into it. Hope this should provide ideal solution.

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  8. Site inspection to understand the Problem and possible solutions. In the second step discuss with Owners budget and way to go about. In the third stage finalize in consultation  with Owners whether remediation Process should be LSTK or Open Bid. Use available/procured topo maps for quantity takeoff. Keep the bid document as simple as possible and write clearly to avoid legal hassles

  9. Initially, one needs to have either a series of photographs of the terrain of the Association's property, or a better endeavor is to visit the site to examine where and why the flooding is occur.  One also needs to know what the local geology is, e.g., carbonaceous, terrestrial sand, in order to devise a solution.  Additionally, the flooded areas could be converted into artificial wetlands that would soak up the flood waters.  Regrading some of the flooded areas may also be possible so that the current flood waters could be diverted or redirected. 

    Maps of the local are likely to be found in the city hall, or a local university; U.S. flood elevation maps; highway construction maps, and the like.  Another type of map maybe one that is from 80-100 years ago, or older, from the Florida Geological Survey, in the state's capitol, Tallahassee. 

    However, an RFP is not possible at this stage, because there is currently too little information.  How can an RFP be created without the tens of items that are unknown at this juncture?

  10. USGS: https://www.usgs.gov/core-science-systems/national-geospatial-program/national-map.  But is the flooding truly pluvial - or also affected by tides driving groundwater levels up and down?

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    1. hi Peter, I could not find any sea level maps of lidar except VERY small areas. in Florida only Miami. Other sources?