Decide which flood event to model for comparison with SuDS data

[ththelen]

@anardek I am going to list some flood events options for which we have CB SuDS data to compare with ADCIRC model results

[ththelen]

May 13 - 17: Offshore Low Followed by King Tides

Short SuDS data record from CB01 only, but it captures 4 flood events over the ~72 hours of data. Additionally we have a pretty significant rain event the coincides exactly with the last flood on the evening of May 16 / morning of May 17, so we could evaluate multiple drivers. Per my notes, this flooding was driven by an offshore low May 11-14 combined with king tides May 14-20

SuDS data log for May 13-18

FIMAN hourly rain data for May 13-18 in inches

FIMAN water level data from May 9-21. There was flooding outside of the date range the we captured with the SuDS. Note that the road elevation at CB01 is 2.38 feet.

[ththelen]

April 17-18: Low Pressure System and Rain

Two flood events at CB01 during back to back high tide. First flood driven mainly by low pressure system. Second flood exacerbated by heavy rain event. However, there is an unfortunately timed SuDS data gap for the high tide immediately following the second flood.

SuDS data log for April 16-22

FIMAN hourly rain data for April 16-22 in inches

FIMAN water level data from April 16-21. Note that the road elevation at CB01 is 2.38 feet.

[ththelen]

June 14-16: CB01 and CB03 Data for Small Floods from King Tides

The flooding resulting from king tides June 12-16 was relatively low intensity compared to other events. I also did not identify any drivers besides tides. However, it is the only event for which we have data from both SuDS CB01 and CB03 available.

CB01 SuDS data log for June 13-17

CB03 SuDS data log for June 13-17

No significant (greater than one quarter inch) rain events occurred June 13-17

FIMAN water level data from June 13-18. Note that the road elevation at CB01 is 2.38 feet, and at CB03 it is 3.1 feet

[ththelen]

@anardek I looked back through the NC Sea Grant Proposal, but I could not find the tidal forecast threshold that CB uses to determine when they should be alert to flooding like we discussed on Thursday. In talking with Daniel on Friday, it sounded like this number was somewhere between 5 and 6 feet on the open coast. However, he was not exactly sure because it is the town environmental staff and not the stormwater folks that handle road closures. What would you think about reaching out to CB again to confirm that threshold?

[anardek]

Have you checked the engineering/bulkhead report? It might be there. Once we check that, then I'll reach out.

On Mon, Jan 23, 2023 at 10:00 AM Thomas Thelen @.***> wrote:

@anardek https://github.com/anardek I looked back through the NC Sea Grant Proposal, but I could not find the tidal forecast threshold that CB uses to determine when they should be alert to flooding like we discussed on Thursday. In talking with Daniel on Friday, it sounded like this number was somewhere between 5 and 6 feet on the open coast. However, he was not exactly sure because it is the town environmental staff and not the stormwater folks that handle road closures. What would you think about reaching out to CB again to confirm that threshold?

— Reply to this email directly, view it on GitHub https://github.com/NCSU-CHAZ/Sunny-Day-Flooding/issues/10#issuecomment-1400491906, or unsubscribe https://github.com/notifications/unsubscribe-auth/ANXYL55TNQR4LXOCS7EXYRLWT2MHFANCNFSM55ILJNRQ . You are receiving this because you were mentioned.Message ID: @.***>

[ththelen]

Just checked the APTIM Engineering report and did not find it there. Also, based on what I heard from Daniel on Friday it sounds like that threshold has changed somewhat recently when new staff took over responsibility for closing Canal Drive. Questions that might be worth asking the town that come to mind are:

1. At what tidal forecast water level threshold do you plan to close Canal Drive?
2. Is there anything besides the tidal forecast that goes into that decision?
3. What source do you use to check tidal forecasts? (Daniel uses an app called Tides)

[ththelen]

Hello @anardek and @caseydietrich, I have come up with my list of events that I think could make for an interesting paper. I settled on 5 events that cover most of the driver combinations that Katherine put up on the board in our meeting last week. I also like these events because we have data from both CB01 and CB03 for all but one of the events. This way we get to show off more of our field data and tease out more of the difference between the lower CB01 location that is more prone to ocean-side flooding and the higher CB03 location that is more prone to land-based flooding. I would very much appreciate your feedback on the events I picked out and the story we can tell with them. Water level time series for the events and some thoughts (on the slides)/ramblings (in the notes) can be found in the attached PowerPoint.

I think my next step is to come up with a framework for preparing (e.g., cutting down our ADCIRC mesh for faster runs), standardizing (e.g., setting a constant river discharge multiplication factor) and completing (e.g., Casey is currently the only one who can prep NAM input files) the model runs. I will start a new thread dedicated to completing the model runs for this discussion.

https://docs.google.com/presentation/d/17LP5u68B6H0FHv0kHljjfIJBYpBtRdHZQ5lU1R8c0BQ/edit?usp=share_link