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We'll go ahead and get started. 00:00:20
And call the meeting to order at Sullivan's Island. 00:00:23
Mission. It's June 11th, Commissioners. 00:00:26
Present our coal Peterson, Paletti Schroeder. 00:00:29
Coles, Howard. 00:00:34
Have the FOIA requirements been met, Pam? 00:00:37
Thank you. 00:00:40
And can I have a motion to approve the May 14th 2025 minutes? 00:00:42
I'll make that answer. 00:00:48
2nd. 00:00:50
All in favor. 00:00:52
Motion passes. 00:00:54
OK, any public. 00:00:56
Correspondence. 00:00:59
No, great. Nobody's here, so that's good. 00:01:01
We will move into the memo. 00:01:04
To town council, Did everyone have a chance to review that? 00:01:07
OK. And Charles, I'll let you. 00:01:12
Yep, so. 00:01:15
At our meeting last month. 00:01:17
We had citizens speaking during the public hearing for the. 00:01:21
Resilience plan and she brought up the. 00:01:26
Possible benefits to dredging Cove Creek as a way to address some of the storm water concerns. 00:01:30
And so. 00:01:40
Planning Commission had asked. 00:01:41
Staff to draft this memo to council noting that this. 00:01:43
Judging. 00:01:50
Consideration is noted in the comp plan which was recently approved and it was also in the previous iteration of the comp plan. 00:01:52
And. 00:02:00
There are maybe some. 00:02:02
Opportunities. 00:02:05
At this moment. 00:02:07
Or in this moment to. 00:02:09
Pull this dredging project forward along with some of the other dredging that's going on in the Intercoastal Waterway or is 00:02:13
planned for the Intercoastal Waterway. 00:02:18
And so it just seemed like an appropriate time and all that is outlined within this memo if there are. 00:02:22
Questions about. Happy to answer. 00:02:30
Or if anybody has some changes they'd like to make. 00:02:36
Stuff can keep it there on the backside down, or it can be. 00:02:40
They can use those people that are losing them. 00:02:43
I'll have to get carried off. 00:02:46
These other locations is that. 00:02:48
Peaceful thing. 00:02:50
I don't think that we have control over where they put the dredge spill. 00:02:52
It's certainly something that we can bring up if we do get. 00:02:59
To that point where we are going to do some dredging as to where that dredge spill will be. 00:03:02
Offloaded. 00:03:08
And, umm. 00:03:10
However, I don't think in. 00:03:12
Any circumstance is it likely that we will have? 00:03:14
Exclusive right to that dredge fill for our personal uses. 00:03:18
But. 00:03:22
It's worth. 00:03:24
Asking. 00:03:25
Yeah. 00:03:26
We could. I mean, it won't go far. It'll go to one of the spill islands right out there next to. 00:03:27
The Coastal Waterway. 00:03:34
Yeah, Rebecca, you may have some information on I know of. 00:03:36
It seems like I've read about at some point. 00:03:40
Regarding what's dredged. 00:03:43
Depends on where it comes from as to where they can put it because it has to be a certain quality to go on the beach, correct? 00:03:45
That's right, to go on the beach or to go back in the marsh even there is a method now called thin layer displacement where they. 00:03:52
Will dredge a channel and then. 00:04:00
Spray that sediment back on the marsh in a very thin layer to help that marsh build up in advance of rising seas. 00:04:03
And this would be the perfect. 00:04:12
Opportunity for that type of marsh restoration since. 00:04:15
The sediment is coming from such a shallow, recently silted system versus. 00:04:20
The deep bottom of the. 00:04:25
Of the Charleston Harbor where you know that hasn't that. 00:04:27
The silt tends to hang on to particles of. 00:04:31
Contamination in our water and the longer it's been in there potentially. So it is a good opportunity, however. 00:04:35
That whole process is. 00:04:42
A huge endeavor by the Army Corps. It takes 2 very different types of equipment to operate the dredging versus the thin layer 00:04:46
displacement. 00:04:51
And that would certainly have to be. 00:04:56
Under the charge of the arm of an Army Corps project. 00:05:00
But certainly we're investigating as the Army Corps is active right now in the ICW and otherwise. 00:05:03
That what they did down. 00:05:11
Marshall, David. That. 00:05:13
Similar to be tree nourishment, the pumping and piping. However to get the thin layer versus one sort of. 00:05:18
Underwater mound. 00:05:27
Takes special equipment so different from what they use for bee tree nourishment. 00:05:29
But similar concept. 00:05:35
I know they are behind IKEA now. 00:05:39
But who has talked to you? 00:05:44
We have been spoken. 00:05:48
To the dependable time events or. 00:05:49
Who's targeted and where? Where are we? 00:05:54
With regard to the ongoing project. 00:06:04
This is a request to have the Council look into. 00:06:11
Dredging of Coke Creek. 00:06:18
And so this is an initiation of. 00:06:21
Potential projects for the future. 00:06:24
And completely separate from what's going on currently. 00:06:28
At. 00:06:32
We have not engaged with the Corps of Engineers at this point in time, no. 00:06:37
This is sort of starting. 00:06:42
Yes. 00:06:45
Something that Council may want to consider given. 00:06:51
The storm water projects and the lack of public access, well, public access access is definitely diminishing back there, say from 00:06:55
the kayak launch. 00:06:59
And so forth. So that's. 00:07:04
What? Umm. 00:07:07
He prompted this by residents that spoke out about it. 00:07:08
And then something for council to consider since it's in the comp plan. 00:07:12
I was just curious if they had approached it at all. 00:07:16
You know, it's been receptive. 00:07:19
No, I don't think it's council takes an interest in this. They would ask staff to. 00:07:26
Try to coordinate some conversations with the. 00:07:32
Army Corps. 00:07:36
The Fort. 00:07:37
And any other. 00:07:39
Potential entities that we could. 00:07:41
Partner with to. 00:07:43
Create some. 00:07:45
What's the word I'm looking forward? Not symbiosis, but something similar to that word? 00:07:49
To get traction to move this forward. 00:07:56
Synergy, that is the word. 00:08:01
Thank you very much, Dave. 00:08:04
Yes, please. 00:08:08
Have a question? All paper motion pass. 00:08:19
Thank you very much. We'll. 00:08:26
With us. 00:08:28
Structures that. 00:08:33
Yes. 00:08:37
Beginning to touch on it, correct? 00:08:40
Today I'd just like to give you all a presentation about. 00:08:43
Some concepts regarding erosion control, control measures and structures and. 00:08:49
Kind of get. 00:08:57
Get your head strapped around what we could do, what the ordinance currently allows, and. 00:08:58
The direction that we're getting from our consultants with the sea level rise resilience plan. 00:09:05
And just kind of take it from there. 00:09:12
Not not trying to brush anything really, but wanted to get this started. 00:09:16
As we're wrapping up that sea level rise plan, and we should have some. 00:09:22
Concrete recommendations from them. 00:09:26
Very soon. 00:09:29
Umm. This is the, uh, current. 00:09:31
RC Area erosion control structure ordinance, section 2169. 00:09:36
In short. 00:09:43
It does not allow. 00:09:44
Erosion control structures, except those that were present when this ordinance was. 00:09:47
Adopted, uh. 00:09:52
And those pre-existing structures. 00:09:54
Are allowed to be repaired if they're not damaged by more than 50%. 00:09:58
And that's that's the current status. 00:10:03
With this ordinance. 00:10:06
Additionally, there's a. 00:10:09
A section in the Rs district. 00:10:12
This is the single family residential district that. 00:10:16
Prohibits erosion control structures. 00:10:20
So that that's our current framework that we have. 00:10:25
Operating under on the town. 00:10:30
In the town today. 00:10:32
Talk about erosion control structures. Oftentimes we're thinking about hardening the. 00:10:37
Coast to prevent. 00:10:44
You know, water from coming in or. 00:10:47
Land from going out. 00:10:50
Wanted to or both those things are the goals there. 00:10:52
But what we have on this? 00:10:56
Image in front of you is an example of kind of what. 00:10:59
What really happens when you have a seawall? 00:11:03
The wave action is reflected off of the sea wall and we tend to get erosion right at the base of the seawall. 00:11:06
And if. 00:11:16
If it were on a beachfront and we see it across the way at Breach Inlet, there's. 00:11:18
Erosion around. 00:11:24
One property that has a wall on the beach and. 00:11:26
You know, at certain high tides, you can't walk around the beach there anymore because there. 00:11:29
The ocean comes into the wall. 00:11:36
We have some examples on the back beach of where? 00:11:41
People have put. 00:11:45
A retaining wall. 00:11:47
Our or See well, however you want to look at it. 00:11:52
On their property and we see. 00:11:55
The adjacent property is eroding. 00:11:57
That behind it? 00:12:00
This is adjacent to this property. 00:12:03
Your answer on Dodson's property. 00:12:08
Yes. 00:12:10
That and that is something that I believe he would like to achieve for himself. 00:12:11
Similar situation to his neighbor. 00:12:18
Here's another picture of that location where we've got the erosion coming. 00:12:25
And from the. 00:12:30
Wave action that comes around here and it. 00:12:32
Pulls sediment back. 00:12:35
Creates kind of a churn. 00:12:37
This is on. 00:12:40
Off Thompson Ave. near Station 15. 00:12:42
That was built. 00:12:49
Problematically and I think 2021. 00:12:51
Yeah. 00:12:56
No it didn't. 00:13:00
Possibly could. 00:13:02
Then this just kind of gives you. 00:13:08
The basis for where we are today. 00:13:11
Now have this new. 00:13:14
Director of Natural Resources and Resiliency Rebecca, who's been here with us a year now, doing a great job. 00:13:16
And. 00:13:23
Helped me. 00:13:24
With this project here. 00:13:25
I'm presenting to you all today. 00:13:28
And just a quick update we've been through. 00:13:32
Phases one and two of this adaptation plan and. 00:13:36
You know, as of last month. 00:13:40
The consultants met with. 00:13:43
Our Commission and did an open house here to discuss where they're headed with the final draft and they'll be presenting that to 00:13:45
council. 00:13:49
In July, I believe. 00:13:54
From correct, yeah. 00:13:56
In there they have these 10 strategies that. 00:13:59
Are to address. 00:14:03
Creation of more resilient community and adaptations for sea level rise. 00:14:05
Two of them #4 and 7. Marsh Management and Protection and. 00:14:11
New and redevelopment of policies. 00:14:16
Are what I feel like. 00:14:19
This Commission should discuss in consideration of that RC. 00:14:23
2169 section of the ordinance. 00:14:27
What they were discussing with marsh management and protection is ordinance review, proposed revisions, promotion of living 00:14:34
shorelines and marsh stewardship activities. 00:14:39
Still needs to be fleshed out some more. And so we've kind of. 00:14:45
Taken taking the lead on. 00:14:49
Giving some. 00:14:52
Some meat on those bones. 00:14:54
Rebecca, do you wanna? 00:14:56
Speak to this a little bit. 00:14:57
Sure, yeah. 00:15:02
The marsh management aspect of the resilience plan. 00:15:05
Will be looking at ways to at once preserve. 00:15:11
The marsh and keep it. 00:15:16
Alive in a time. 00:15:19
When water is. 00:15:20
Rising more frequently and with those higher tides bringing rack and smothering. 00:15:23
The marsh as well, we're seeing issues in the salt marsh that. 00:15:29
Are new to the region so. 00:15:34
Here is a rendering from the City of Charlestons Land and Water Analysis that informed their comprehensive plan update in 2020. 00:15:38
That shows. 00:15:49
Some different arrangements of what the marsh can look like at the shoreline. 00:15:51
Where it is allowed to migrate inland and upland or. 00:15:57
Is held in place by a hardened structure and what some of the repercussions of that can be for habitat value. 00:16:03
As well as what the hardened structure does not solve. 00:16:12
With the water table rising behind that structure so. 00:16:16
Sort of a useful display of some of the. 00:16:20
Benefits and unintended consequences of different shoreline treatments. 00:16:24
And when we look at the alternatives between what we call in the industry green infrastructure, meaning more vegetated based 00:16:33
practices for erosion control. 00:16:39
Versus Gray infrastructure, think concrete. 00:16:45
Then there is a spectrum actually. 00:16:50
But there are aspects of the living green infrastructure that mimic the more traditional. 00:16:54
Bulwark robust approaches that we're used to seeing up creeks from. 00:17:01
Shoreline erosion control measures that. 00:17:07
Took place in the 70s and 80s and you know, we still have evidence of on our landscape so. 00:17:10
One of the key. 00:17:16
Aspects that is now permissible in South Carolina is a. 00:17:18
Oyster reef sill. 00:17:23
So that is immobile rock structure, shell structure of living oysters. 00:17:26
That breaks the wave energy before that wave, whether it's from boat wake or just a storm coming through. 00:17:32
Laps up against the shore. 00:17:40
Potentially otherwise eroding the marsh. 00:17:43
And oysters as a reminder. They can only attach. 00:17:45
If there's substrate already present. 00:17:50
So sometimes what that looks like Outback of Thompson, which I was. 00:17:53
I found interesting to realize was. 00:17:59
Someone had an engine block out in the marsh that they used as an anchor chain. 00:18:02
And that is now a cluster of oysters and an otherwise mud flat. 00:18:07
So not an ideal, but of substrate. 00:18:13
Fortunately, DNR has been working on this for years, and they've come up with some really good. 00:18:16
Options for substrate to get oysters started in a marsh. 00:18:22
And dissipate that wave energy. 00:18:26
To allow vegetation to fill in. 00:18:29
Here's an example from pretty close to home that's off Gold Bug Island. 00:18:32
An oyster, a living shoreline, an oyster reef. 00:18:38
Was put there at this sort of. 00:18:41
Eroding hairline of the marsh where wave. This is actually right by their boat landing, so you can imagine. 00:18:43
As boats were coming in along the ICW, that wave energy. 00:18:50
Was too much for the marsh to keep up with with these high high tides. 00:18:54
At the same time. 00:18:59
After installing this in 2016, if we go to the next site I believe we can see. 00:19:00
This is a project that The Nature Conservancy spearheaded. 00:19:07
And you can see that green line is where the marsh grass ended. 00:19:12
In 2016 before construction. 00:19:16
And the last time that they did a comprehensive analysis of this project. 00:19:20
It was all the way at that red line, so that's a lot of marsh to regain in a short few years. 00:19:24
And all because that. 00:19:32
Oyster reef has dissipated the wave energy. 00:19:33
Oh great. 00:19:40
And then just to sort of. 00:19:42
Give you a schematic of how. 00:19:45
And why this works? 00:19:47
The oysters as well as keeping the waves from eating up that. 00:19:48
Bank of the salt Marsh. 00:19:52
Are also slowing the water down enough that new sediment has a chance to drop out and rebuild. 00:19:54
That grade? 00:20:01
Does create. 00:20:03
Not just give the vegetation a chance to reestablish, but raises the grade of the marsh where it has been. 00:20:05
Eroded and has the bonus of providing habitat. 00:20:12
Looking at the spectrum again of. 00:20:20
Kind of green to Gray infrastructure. 00:20:24
You can see that in the top right where it's just vegetation and nothing basically if we did nothing. 00:20:27
And it was just vegetation up to the water's edge. 00:20:35
We would expect to see further. 00:20:39
Degradation. So doing nothing is not a great option. 00:20:41
Doing the traditional method of the 1970s, installing sheet piling. 00:20:46
Into the marsh. 00:20:52
Doesn't do us any favors either, and perhaps is a worse risk down the line. 00:20:53
When Gray infrastructure fails, it tends to do more harm. 00:20:59
Then it was intended to preserve all those years so when green infrastructure quote, UN quote fails. 00:21:04
When something blows out, the repercussions typically are very minimal. It will. 00:21:13
Heal itself before the next storm. 00:21:18
With Gray, infrastructure collapses, if that. 00:21:21
Erosion that scour at the base or around the edges. 00:21:24
'Cause that wall to collapse. 00:21:29
Then the land would lose a lot of soil all at once. And you would. 00:21:31
Have to move the new wall. 00:21:36
Much further inland, so really not. 00:21:39
And maybe in the short term seems efficacious, but in the long term? 00:21:42
Does more harm than good. 00:21:47
We see with the oyster sill method. 00:21:49
That you do build up. 00:21:53
More of the transition area and therefore the buffer. 00:21:55
Between uh. 00:22:00
Residential or whatever the upland property is. 00:22:02
And the water's edge. 00:22:05
So it turns out it also happens to be much more affordable, so considering. 00:22:13
Really long lengths of shoreline. 00:22:20
Where folks would want to band together potentially to do a project like this. 00:22:23
The distributed cost of management, maintenance, installation. 00:22:29
For plant and or natural process based restoration. 00:22:33
Is typically, you know, an order of magnitude lower than. 00:22:38
The cost of a more heavily engineered or hardened. 00:22:42
Erosion control measure. 00:22:47
Next, we're going to talk a little bit about the. 00:22:54
Policies. 00:22:58
That we might wanna address. Use to address these concerns. 00:22:59
And there are a number of different ways that we can. 00:23:06
Adapt. 00:23:10
This is kind of a. 00:23:12
Sheet that shows things from green infrastructure. 00:23:14
Efforts all the way up to elevating roads. 00:23:19
Creating uh. 00:23:23
Drainage basins. 00:23:24
Elevating houses. 00:23:25
Possibly even relocating homes to higher ground. 00:23:27
Just kind of gives you the. 00:23:31
Idea of. 00:23:33
All the different things that we can do to combat sea level rise. 00:23:34
On the local level. 00:23:38
And this is. 00:23:42
From Florida. 00:23:44
And what they've done is. 00:23:46
Projected where sea level rise is going to be. 00:23:49
And. 00:23:52
Created this. 00:23:53
Green infrastructure area. 00:23:55
To allow the marsh and the. 00:23:58
To migrate to have. 00:24:01
Some space. 00:24:03
For the ocean to rise without. 00:24:05
Negatively impacting. 00:24:08
The residential or. 00:24:10
You know the park. 00:24:12
Behind it in this case. 00:24:14
And as you can see these. 00:24:18
Plant materials that. 00:24:21
Really do well in this habitat, tend to stay low, they don't. 00:24:24
Typically obstruct the view corridors that are. 00:24:29
You know, highly valued. 00:24:33
Aspects of people's property here. 00:24:36
This slide is just to show you. 00:24:40
Where we do have existing. 00:24:43
Bulkheads. 00:24:47
When they do need to be repaired and they ultimately all will need some repairs as shown on that slide, the cost? 00:24:49
For maintenance, there is a maintenance cost involved with these. 00:24:57
There are options to. 00:25:01
Kind of create this intertidal shelf which will add habitat along the. 00:25:04
Head and. 00:25:09
Provide a little bit of. 00:25:12
Protection from scouring. 00:25:14
And, umm. 00:25:16
Pretty much make the bulkhead last longer and. 00:25:19
Less of a detriment to the ecological benefits that. 00:25:23
Or the ecological. 00:25:29
Aspects of the. 00:25:31
That was there. 00:25:32
These are a few. 00:25:36
Uh. 00:25:39
Books or? 00:25:41
Reports that have been done that. 00:25:43
Provide some additional. 00:25:46
Information about. 00:25:48
Shorelines and. 00:25:51
Creating buffers along shorelines and the benefits of them. 00:25:52
These are all local. 00:25:57
Documents from. 00:26:00
DNR. DACC. 00:26:02
We can share this bibliography with you all. 00:26:05
And these are just a couple of examples of. 00:26:11
Ordinances in other places that. 00:26:16
Have buffering requirements which are kind of. 00:26:21
Kind of like a set back but. 00:26:25
In addition to being a set back, there's. 00:26:27
Vegetative requirements, typically within buffers. 00:26:30
In Georgia, they have. 00:26:34
A 50 foot requirement. 00:26:36
So that that would be a natural area and you're allowed to have. 00:26:38
15% of it be an impervious path to get out to say a dock or. 00:26:43
Some other recreational use of the. 00:26:49
Water beyond your property. 00:26:52
North Carolina has a similar. 00:26:56
30 foot buffer with a 20 foot additional area where they don't allow pavements or structures. This is. Along streams or ponds this 00:27:01
is. 00:27:05
Not necessarily our. 00:27:10
Environment, but it does have the same kind of. 00:27:12
Gives you a cross section of kind of what. 00:27:15
Thinking about. 00:27:19
And then closer to home. 00:27:22
Right along the Ashley River in North Charleston, they have 100 foot shoreline buffer where they. 00:27:25
Don't allow any development and you can see the result is. 00:27:31
Looks wild. 00:27:35
Along the Ashley. 00:27:37
Here is a schematic that. 00:27:42
That as you go up the Bank of the. 00:27:47
Marsh the different species that do well in those habitats as we go from. 00:27:52
The water to the oyster bed. You got your marsh grass spartina. 00:27:58
Then some of these. 00:28:03
As a marsh indicators the sea oxide Daisy. 00:28:05
Seaside Goldenrod. 00:28:09
And then as you get to the higher ground. 00:28:11
The live votes. 00:28:14
Start that. 00:28:15
Kind of based on all that thought. 00:28:22
We've got some ideas that we want to share with you all today. 00:28:25
From staff perspective. 00:28:28
The first thing we'd recommend is that we maintain the prohibition for erosion control structures in the. 00:28:32
Recreation and Conservation District. 00:28:39
And justice add language to that section that. 00:28:43
When these. 00:28:48
Structures need repair. 00:28:50
That they're required to do some intertidal shelf. 00:28:52
Type treatment or add. 00:28:55
Living Transition. 00:28:58
Transition zone additions which are. 00:29:00
Essentially like. 00:29:03
Imagine like. 00:29:05
Putting. 00:29:08
Ornaments on the wall. 00:29:12
That would allow oysters or other. 00:29:15
Mollusk type animals. 00:29:20
In the ocean to latch on to to create. 00:29:22
Life along that wall surface. 00:29:26
And then in the Rs district. 00:29:30
Create a natural barrier along the critical line that could be a buffer. 00:29:34
Established between the critical line and a land elevation of about a foot and a half above the critical line. 00:29:39
I've got a slide that kind of shows this. 00:29:46
Might be easier just to look at the slide. 00:29:49
Talk about this. 00:29:52
So here's our. 00:29:55
Down here on the blue line. 00:29:58
And what what what I was? 00:30:00
Just basically saying, is this first foot and a half above the marsh as we grade up into the higher land? 00:30:02
That that be maintained as a buffer area, not putting a. 00:30:09
A number like a 30 foot buffer or 50 foot buffer or 20 foot buffer but. 00:30:13
Basing it on how the topography changes and where that topography rises a foot and a half above the critical line that would give. 00:30:19
The Marsh. 00:30:27
A chance to migrate it would createspace for. 00:30:28
Sediment to. 00:30:32
Be pulled out of runoff before it goes into the marsh. 00:30:35
And infiltrate into the soil. 00:30:40
And other benefits to that. 00:30:42
Yeah, I think one that we have failed to touch on yet is the pollution removal from the upland. If you have storm water running 00:30:44
off of the roads, everyone's little oil leaks have accumulated in that water having. 00:30:51
A little bit of a vegetated buffer has been shown to pull out like 50% of pollutants in storm water runoff. 00:30:59
In just a very small buffer strip. So that's one benefit of having that. Another is, you know, a foot and a half higher than high 00:31:08
tide happens pretty frequently. 00:31:14
So if we think about making sure. 00:31:21
That people don't have things in that area that could get damaged. 00:31:24
A frequent storm that we have. 00:31:29
Think also preserves that private property value giving. 00:31:31
The elevation of water, a little room to breathe without causing disturbance. The plants can handle it. 00:31:35
And then another sort of Co benefit just being. 00:31:43
The habitat and the fact that anything that salt tolerant. 00:31:48
If you picture like how the dune grasses are. 00:31:53
You you don't really get height with those vegetation, so I think it would also be very aesthetically pleasing. 00:31:57
To have a buffer of what's flowering right now, which is that yellow sea oxide Daisy. 00:32:04
It would be an easy thing to. 00:32:11
For people to maintain. 00:32:14
And keep looking good. 00:32:16
And then once you. 00:32:20
Get above that foot and a half we would. 00:32:21
We would propose to allow. 00:32:23
About a foot and 1/2. 00:32:26
A non hardening erosion control measure. 00:32:28
Think like the enviro lock. 00:32:31
Sandbags that have been put in at the Cove Inlet Bridge project, something like that could be stepped. 00:32:35
Increasing. 00:32:43
To allow. 00:32:44
In these areas where we do have really low elevations on some of these lots to allow them to gradually. 00:32:46
Build their elevation. Build their. 00:32:54
Property up to where the building pad is set at 7 1/2 feet above sea level, which? 00:32:57
Predictively. 00:33:05
Will be outside of extreme tidal events. 00:33:07
50 years from now still. 00:33:11
So that would. 00:33:13
Creative. Resilient. 00:33:14
Situation for those homeowners, it would. 00:33:15
Be a change in the ordinance because some of these properties are at 5 feet, so this would be bringing in more than a foot of fill 00:33:19
in certain circumstances. 00:33:23
Really. 00:33:30
Property. Adjacent schools. 00:33:31
I think that we would be looking at this. 00:33:36
More broadly than that. 00:33:42
Because there are other properties that are sitting and so. 00:33:44
You know, on the other side of the street from. 00:33:48
Like the properties on Osceola that are across the street are also very low in some cases. 00:33:52
One thing that we kind of tossed around a little bit and I'll go back to the previous slide. 00:33:59
Was. 00:34:05
Perhaps this? 00:34:06
We put parameters in place and. 00:34:09
Put this as a special exception. 00:34:12
Such that. 00:34:15
Bound specifically to these. 00:34:18
Concepts, but that if there is a. 00:34:20
Property that is experiencing hardship because it is of low elevation lot. 00:34:23
That we could take it to the. 00:34:29
BZA and they could get a special exception to elevate to the seven and a half feet and. 00:34:31
There would be kind of guidelines in place for. 00:34:37
What that elevation looks like that the slope of the lot? 00:34:42
Couldn't be more than. 00:34:46
5% potentially and. 00:34:47
These erosion control structures no more than 18 inches on the property to hold in that. 00:34:50
Fill dirt that would bring the elevation of the property up. 00:34:55
It would make sense if one. 00:34:59
Resident did it that adjacent residents would have to do it as well or else it's going to cause. 00:35:01
Interesting. 00:35:10
Well. 00:35:11
These uh. 00:35:12
And we did some analysis on. 00:35:14
Elevations of lots around the island. 00:35:17
There are. 00:35:20
Most of them. 00:35:23
Are along the. 00:35:25
Waterfront for sure. 00:35:26
And they're not. 00:35:28
Too many lots that would need more than a foot of fill to get to a 7 1/2 foot. 00:35:31
Building pad. 00:35:37
And this would be the responsibility of the homeowner. 00:35:39
To elevate their property, correct? 00:35:43
Yes. So it would be the homeowners expense I guess. 00:35:46
The way I'm thinking is if you just have two homeowners that want to do it and that can afford it, and maybe some other neighbors 00:35:50
can't afford it, and what is that going to create? 00:35:55
So one of the things that's also consideration here is expanding the storm water management plans. 00:36:00
Adding some metrics into that that would. 00:36:07
You know engineering can solve a lot of problems. And if it's a. 00:36:11
Problem of. 00:36:16
5000 square feet of runoff. 00:36:19
From storms. 00:36:22
I think that there are engineering solutions to manage that on those properties. 00:36:24
And if if somebody's coming and wanting to do that elevation, then that. 00:36:30
You know that would our existing stormwater requirements would be. 00:36:35
A part of that project and they're. 00:36:40
This could be expanded a little bit. 00:36:42
Are there grants available? I'm just sorry, Laura, it just worries me creating an ordinance. 00:36:44
That some you know. 00:36:50
That some homeowner homeowners will take advantage of immediately, but then others. 00:36:54
Are not going to be able to afford to. 00:37:00
And then? 00:37:01
It's going to create problem more problems with their property, especially when I'm considering. 00:37:02
On the Creek on both sides where it floods of the island. 00:37:08
I don't know. That's yes. And that's what I always thought about when it comes to a bulkhead. And you can clearly see that 00:37:13
happening on the beach and the photos that you saw that. 00:37:18
Where you have the bulk ahead. 00:37:23
The properties adjacent. 00:37:25
Eroding so anytime you build something up it. 00:37:27
You know the water is going to go where it can. 00:37:30
I just think that's something we have to be. 00:37:34
Pretty careful with. 00:37:36
Yes. Umm. 00:37:37
But like you said, engineers can solve just about anything. 00:37:38
So my question was, I know we currently have ordinances in place that require. 00:37:42
Homeowner. 00:37:47
To maintain the water that is collected on their property, right? So if they were to build their property up by more than a foot. 00:37:48
Then wouldn't they also still be required to? 00:37:57
Figure out how to maintain that water on the property and prevent it from. 00:38:01
Draining off into someone elses property so I think. 00:38:06
Well, but if the water is coming from. 00:38:09
Creek, you can't really manage where that water's. 00:38:11
Coming. You see what I'm saying? It's if it's not flowing often to someone else's property, but if it's flowing back into the 00:38:15
Creek, I think that would be the intent of this. 00:38:20
I think the intent is on the Creek side is so that you have a little bit of a buffer to keep the, yeah. 00:38:25
King water from coming in. Yeah, so. 00:38:32
If it's coming from. 00:38:35
Interior, Yeah, we're talking about water coming up. 00:38:38
On this property. 00:38:41
And essentially the. 00:38:45
Creating this buffer area along it would be. This property would be. The next property would be all the properties that would have 00:38:48
that buffer area. 00:38:51
Associated so there would be. 00:38:55
Space on anyone of these properties between the critical line and a foot and a half above the critical line where? 00:38:59
Migration of the Marsh. 00:39:08
Influx of high tides can come in. 00:39:11
And go out without affecting any of the properties in a negative way. 00:39:14
Can I ask a question? Yeah. 00:39:20
The oyster sill, the reef that you you showed the example of that in three years time. The grass. 00:39:22
Greatly increased. 00:39:29
That that oyster sill was pretty substantial and pretty high. 00:39:30
When those strategies be the strategies that would be the lead strategies on the Creek side of this. 00:39:35
Island. Is that what we would be using as oyster sills or Reeves? 00:39:40
And how high would they be and. 00:39:45
That kind of that's sort of my first question. I think they would be. 00:39:48
You know, on an individual basis. 00:39:54
Whether or not it would be appropriate, some areas of the island it would be more appropriate than others. 00:39:57
One thing that we discussed was down at. 00:40:05
Down at the end of the island where we're. 00:40:10
Discussing. 00:40:14
Doing a. 00:40:16
Pocket Park here at the end of Metal St. 00:40:18
That there may be an opportunity to do. 00:40:22
A living Shoreline demonstration project here, if that. 00:40:25
All pans out. 00:40:29
That this would be a good candidate location. 00:40:30
4/1. 00:40:34
And that you know. 00:40:37
Most of these properties that are already hardened along the shore would not be good places to propose one, but. 00:40:39
Back along here where we had Marsh. 00:40:47
These could be places that would be. 00:40:51
Good good locations for. 00:40:54
Potential oyster? 00:40:57
And those oyster reefs wouldn't really interfere with the ability of the owners to use their. 00:41:00
Their docks and their boats, they could still. 00:41:05
Yeah, it would be. They should land there. It would be boat and walk in. 00:41:08
The inland it would be a shore word of those. 00:41:11
Boating locations you wouldn't interfere with their ability to enjoy No, and it wouldn't be hot. There wouldn't be high enough to 00:41:14
affect the. 00:41:18
The walkways and then. OK, thanks. 00:41:22
Yeah. 00:41:24
In that particular area we really in. 00:41:31
It is. 00:41:35
The marsh is growing in that area of the island. 00:41:36
Silting in. 00:41:41
Yeah. 00:41:44
Let's see if there's anything else that we missed in here. 00:41:49
Some other things that we. 00:41:53
Thought were worth considering as we talked about this we're. 00:41:55
Um, redefining the term pervious. 00:41:59
What would a pervious material is in the definitions on the island? 00:42:02
And then? 00:42:09
Possibly. 00:42:10
You know this. 00:42:11
Creation of a metric for what is a high risk or a low elevation site that would be eligible for. 00:42:13
A special exception to do this. 00:42:21
Increased fill work. 00:42:24
And then, then. 00:42:28
More of the inland areas of the island. 00:42:29
Where they, where they're some, some lots are in bowls essentially. 00:42:32
Creating opportunity for them to elevate those properties so that the building pad would be at least 6 inches above the crown of 00:42:39
the road. 00:42:43
To because as our stormwater master plan is implemented. 00:42:48
More and more stormwater will be. 00:42:53
Captured in the right of way and. 00:42:56
Brought to the out falls. 00:42:59
For this for you know. 00:43:02
To leave the island. 00:43:05
Having these bowls in the island. 00:43:07
Is a detriment to that plan because. 00:43:10
The water is going to go to the. 00:43:13
As opposed to into the stormwater system and even if it's. 00:43:14
Going off of your property and your property into the storm water system. But Galley's property is lower. 00:43:18
A lot of it's going to make it to her property instead of into the stormwater system. So that would be. 00:43:25
Another thing to consider as we're talking about. 00:43:30
This whole issue. 00:43:32
And then perhaps defining what a landscape wall is. 00:43:36
So currently. 00:43:40
We uh. 00:43:42
Allow them as a policy, but it's nothing in the ordinance that allows them. 00:43:43
And defining that in such a way that it's different from a non hardened erosion control structure, defining both of those features 00:43:50
so that there's clarity on what? 00:43:54
Is allowed because. 00:43:59
What we see. 00:44:01
And this. 00:44:03
Sort of an example. 00:44:06
But umm. 00:44:08
Not a not the right example because it was for the wrong. 00:44:08
Wasn't really. 00:44:12
Permitted. 00:44:13
This is being considered. 00:44:17
By the homeowner as a. 00:44:19
Landscape Wall. 00:44:22
But what it really is is a. 00:44:24
Erosion control structure. 00:44:27
So it's. 00:44:31
Taking advantage of that. 00:44:33
Term and utilizing it right at the property line. 00:44:35
To create. 00:44:40
A hardened shoreline. 00:44:43
Yeah. 00:44:46
Definition. 00:44:48
Yeah. 00:44:54
I'll go into a little more detail. 00:44:58
Currently. 00:45:04
Pervious materials are defined as any material. 00:45:06
Through which water can be easily absorbed or passed at a minimum infiltration rate of two inches per hour. 00:45:09
Such as, but not limited to grass. 00:45:17
Uncompacted gravel. 00:45:20
Shell and crushed stone. 00:45:21
When you put down. 00:45:26
Uncompacted gravel or uncompacted shell and crushed stone is the driveway. 00:45:30
It gets compacted. 00:45:36
It ceases to be pervious. 00:45:38
Grass, I mean. 00:45:42
Turf grass is somewhat A pervious surface, but. 00:45:46
Not really like. 00:45:51
What we're if we're asking for somebody to. 00:45:53
You know, put down pervious surfaces. That's not. 00:45:57
What we're really looking for and then. 00:45:59
When we talk about this minimum infiltration rate of two inches. 00:46:02
Per hour. 00:46:07
Yeah. 00:46:13
And it doesn't. 00:46:14
Really match with real world conditions like their. 00:46:17
Engineers tend to push back on this and say. 00:46:25
What do you mean? 00:46:28
This doesn't make sense to me so. 00:46:29
So the papers are in. 00:46:31
So it. 00:46:35
Those can be so if they've got gaps in them that are maintained. 00:46:37
And then below they have the. 00:46:42
Storage basin that's filled with rock that has lots of space in between the rocks. 00:46:44
That works. 00:46:50
Can be a legitimately. 00:46:53
Pervious surface. 00:46:55
Basically. 00:46:57
I just think it could be better. 00:47:00
Would you agree? 00:47:03
A lot better. 00:47:04
Yeah. 00:47:06
What would be better? 00:47:10
Yeah, we have. 00:47:12
Really good data from. 00:47:15
The US Department of Agriculture on runoff. 00:47:18
Ratios How much rainfall goes into the ground after traveling over. 00:47:22
A forested area all the way down to concrete. Concrete, as you can imagine. 00:47:28
100% of the precipitation turns into runoff or ends up in a pipe somewhere. 00:47:34
Forested areas in the Francis Marion we have numbers that suggest 80%. 00:47:40
Of precipitate of rainfall. 00:47:47
Will go into the ground. 00:47:49
20% ends up in a nearby stream. That's huge. That's a lot. 00:47:51
Lawn. Lawn is somewhere more like. 00:47:56
40 Excuse me? 00:48:02
I switch the ratios on you because I talked about 100% for. 00:48:03
Picture 20% as the ratio for the forest. 20% of that rainfall turns into runoff in the stream. 00:48:08
For LON, that number gets up past. 00:48:15
50% in the 60s. 00:48:19
So going from only 20% of rainfall going into a Piper tidal Creek that can only carry so much to 60% of that precipitation is a 00:48:23
huge jump. 00:48:28
And then just thinking about these more engineered systems with. 00:48:34
Even a gravel basin with lots of poor space where that water could move fast down into the sandy soil below. 00:48:39
It can't if it's silted in. 00:48:47
So just also recognizing some of the maintenance burdens of these engineered systems and how to maintain. 00:48:49
The efficacy of those structures overtime is an important consideration for keeping something pervious. 00:48:58
So it's actually functioning. 00:49:05
For the homeowner and for their neighbors sake for. 00:49:07
Years after construction. 00:49:11
But then also thinking with perviousness. 00:49:15
That it's not just about storm water, it's about the ability of that system to filter out contaminants before they end up at the 00:49:19
outlet at the marsh. 00:49:24
And with this ordinance in particular, I think we started to. 00:49:31
Consider perviousness. 00:49:36
Because of other municipalities that have. 00:49:38
Created these buffer programs is primarily to keep sediment out of creeks and if you've been to the Upstate and you've seen the 00:49:41
kind of erosion that happens and. 00:49:45
The way that title or excuse me, that streams will get silted in with orange clay or ditches will get silted in. 00:49:50
That's the primary reason why. 00:49:57
These other immune, excuse me, these other states, Georgia and North Carolina have put these. 00:49:59
Mandatory buffer requirements and. 00:50:05
That acting as a pervious surface is not just allowing water to get through, but it's also allowing. 00:50:07
The trapping of various contaminants, fertilizers from lawns, the oil leaks from cars, etc, etc. 00:50:15
To get locked up in the soil. 00:50:22
And filtered by plants which are actually really good at breaking down oil based. 00:50:25
Contaminants like fertilizers and actual. 00:50:31
Car oil. 00:50:34
What else about perviousness? 00:50:37
Or why? 00:50:42
You know, I think you touched on it a little bit, some of the. 00:50:45
Practices that we're seeing with. 00:50:50
Certified stormwater management plan that has pervious surfaces. 00:50:53
Is that? 00:50:58
They will collect the rain water. 00:51:00
And get it to. 00:51:04
The Street. 00:51:06
As quickly as possible. Not really infiltrating it into the lot, not really recharging the ground. 00:51:08
It's not really being. 00:51:14
Pervious in the sense that there's absorption occurring. It's pervious in the sense that. 00:51:16
They're directing the flow off the property into the proper channel that we allow. 00:51:22
Which in some cases works. In some cases our stormwater system doesn't work today. 00:51:27
So it really just goes across the street to the. 00:51:33
Low neighbors lot. 00:51:37
Anyway. 00:51:42
That's a lot for y'all to chew on. 00:51:43
So I guess my question is. 00:51:46
And thank you this there's a lot of thoughtful. 00:51:49
Recommendations here that I think we really ought to take a closer look at is the next step then. 00:51:52
For y'all to. 00:51:57
Carefully look at what zoning ordinances or other ordinances that we have. 00:51:58
On the books and figure out which ones we would want to amend to try to adopt these and then bring them here for. 00:52:04
More thorough discussion. Is that the next step? 00:52:11
If if. 00:52:14
If you are. 00:52:15
On board, I was thinking maybe that. 00:52:17
We'd take a month, chew on what has been. 00:52:20
Yes, given to you. Y'all can give you a copy of this presentation today. 00:52:23
And you know, come back to us and say, yes, this. 00:52:29
Something that we want to work on doing and this is not. 00:52:33
Because I think, you know, the devil's in the details and, you know, as we talked about, you know. 00:52:39
If we're if we're allowing one property owner to raise their, you know, left their elevation a foot. 00:52:44
What impacts does that have to an adjoining neighbor? 00:52:50
You know, so I think. 00:52:54
You know, once we dig into some of the details, it's going to be easier for us to have an informed. 00:52:55
Discussion about whether or not we would really recommend that or not. I mean, on the surface it looks like motherhood and apple 00:53:00
pie. 00:53:03
You know, a lot of these are, you know, because it all sounds like great stuff. But then I think when you dig into it, we'll have 00:53:06
to understand what. 00:53:09
Some of the ramifications are of some of these things. 00:53:13
That makes sense. 00:53:17
The staff recommendations that you had up there are all. 00:53:20
All of those recommendations from the consultants are. 00:53:23
No, these are. 00:53:28
From uh. 00:53:31
The two of us. 00:53:32
Based on these. 00:53:34
Kind of broad brush ideas that we've gotten from the consultants which are. 00:53:37
You know, review existing codes and ordinances compared to other coastal communities. Are there places for improvements? Building 00:53:43
footprints? Vegetated buffers? 00:53:47
And then the other. 00:53:52
Piece that they've given us so far is, you know, ordinance review, proposed revisions, promote living shorelines, marsh 00:53:54
stewardship activities. So we took those. 00:53:58
High level. 00:54:03
Thoughts and kind of ran them through our ordinance and came up with these recommendations. So will that. 00:54:04
Will the consulting company come up with their own set of recommendations? 00:54:10
Yes. And those will be in a report presented next month. So it's also a very timely in the sense of. 00:54:15
Having this perspective before that resilience plan is published. Reviewing. 00:54:23
Their final? 00:54:29
Recommendations. Thoughts, ideas, Considerations, Infographics. 00:54:30
It'll be a good visual communication tool, I imagine. 00:54:34
To be able to. 00:54:38
Process the two together and come back with. 00:54:40
A lot of ideas getting at is the information from them is what? 00:54:45
Going to drive this solely correct. 00:54:49
If y'all wanted to. Only if you wanted to, Right, Right. Right. Yeah. I mean, I know that it's probably a lot, but I mean, there's 00:54:56
not someone in left field saying, Oh well, let's do this. And it's not necessarily a thought or recommendation by the consultants. 00:55:03
It's actually just something someone wants. You see, You understand what I'm saying? 00:55:10
I think that. 00:55:17
We'll we'll find that this is similar to what their. 00:55:19
Going to be proposing. 00:55:23
We've talked to them about these ideas and how. 00:55:25
That they they were on board with where where we're directing. So we will see that in July or August. 00:55:31
OK, Yeah, yeah. And and. 00:55:38
You know, to the you know, we've taken a year to get to this point. 00:55:41
We're not, we're not in the nightclub. 00:55:45
Race to the finish line. At this point we right I want to take. 00:55:50
Whatever time we need to do it right. 00:55:55
Get it right? 00:55:57
One in one shot. 00:55:58
Can I ask so the island is what, 3 miles long? 00:56:00
3/3. 00:56:05
Our side umm. 00:56:07
Do we have like? 00:56:10
Enough space between that we would say this doesn't maybe the. 00:56:14
You know certain. 00:56:20
What you just need to do in this spot? 00:56:21
Where is this spot which is building up too fast? 00:56:25
Is there any? 00:56:29
Establishing. 00:56:31
I think that when we look at. 00:56:35
Recommendations. 00:56:38
They may be tailored to different parts of the island differently because there are different circumstances when you're at the 00:56:40
edges of the island versus the central part of the island. What's happening? Yeah, geomorphically is. 00:56:48
Potentially, yes, some zonal. 00:57:00
If you go back to their. 00:57:03
10 strategies, just the broad. Yeah, the broad one. 00:57:04
Yeah. So what else will come into play that we didn't highlight here is residential scale nature based solutions and those will 00:57:08
look very different. 00:57:12
In the middle of the island and they will on front beach, then they will on back beach then they will. 00:57:17
At ends of the island on back beach, from the middle of the island on back beach. There's a lot of nuance and little micro 00:57:22
climates to the. 00:57:25
Different situations and positions on the island. 00:57:29
And the team has spent a lot of their. 00:57:33
Time and work the consultants have on. 00:57:36
Modeling. 00:57:39
How different interventions, how effective they are at reducing flood impacts given different soil conditions. 00:57:41
Elevation types. 00:57:49
So they have some really amazing maps that. 00:57:50
Do that are land based and physical process based. 00:57:53
That kind of. 00:57:58
Highlight different. 00:57:59
Parts of the island. 00:58:01
That would be the most effective place for different. 00:58:02
Solutions and not just talking about. 00:58:05
Living shorelines, but any sort of. 00:58:08
Stormwater control measure you can think of. Where would that work the best? 00:58:11
Seems like they can make a drone video from the talking about now and just show everybody. 00:58:15
Each part. 00:58:21
I'm wondering as possible the other question is 1963 and then. 00:58:22
What are you trying to show us in this? 00:58:27
Compared to the last time sale that actually came from the consultants presentation, we were just using it to highlight their 00:58:30
bullet point strategies. 00:58:35
And those maps are aerial views of the island. 00:58:40
In 1963. 00:58:44
There was number marsh there at the Cove. It was open water. All of that marsh has accreted. 00:58:47
Um, probably as a major, majorly because of as a response to. 00:58:55
The **** that is the Causeway and it's slowing the flow of water and allowing that silt to settle out. 00:59:00
So just to show that this marsh is quite new, it is accreting. Sullivans is really lucky for all the accretion that we get. 00:59:07
And and yet. 00:59:16
Yeah, just that there's an opportunity with that accretion. 00:59:20
To build more sponging of floodwater, more buffering from wave action when we do have storm surge issues or wind from the back of 00:59:24
the beach. 00:59:29
So just highlighting that as an asset that. 00:59:35
Silting in perhaps causes some inconveniences with access to Cove Creek, but otherwise? 00:59:38
It's actually really lucky for a resilience perspective. 00:59:44
Thank you. 00:59:49
This would be stupid question, I'm saying. 00:59:53
Do we give any thought? 00:59:56
Today. 00:59:57
There will be. 01:00:00
There were conversations with SCDOT. 01:00:05
And with McCormick Taylor one of the team. 01:00:09
And. 01:00:13
They will be focusing one of their strategies. 01:00:14
On the Causeway. 01:00:18
Yeah, last December it was. 01:00:25
About a foot from hitting the. 01:00:27
The only thing I was told was they were supposed to put me in a lot more pipes. 01:00:29
Gary, let's come over, you know. 01:00:33
Right now it's just a war way itself. 01:00:36
Yeah, that's a it's a pretty complicated. 01:00:58
Endeavor. 01:01:03
It would change things. 01:01:06
Yeah. 01:01:09
That is a best practice. 01:01:23
It's a lot more expensive to do. 01:01:25
And it doesn't happen in a lot of these roadway projects. It's one of the things that gets cut. 01:01:28
Yeah, yeah. 01:01:42
We have our Commission for us. 01:01:49
No. 01:01:53
Town Updates. 01:01:59
Don't think so. 01:02:01
Motion to adjourn. 01:02:04
Second, all in favor? 01:02:11
We are adjourned. Thank you. Yes, Sir. 01:02:17
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Transcript
We'll go ahead and get started. 00:00:20
And call the meeting to order at Sullivan's Island. 00:00:23
Mission. It's June 11th, Commissioners. 00:00:26
Present our coal Peterson, Paletti Schroeder. 00:00:29
Coles, Howard. 00:00:34
Have the FOIA requirements been met, Pam? 00:00:37
Thank you. 00:00:40
And can I have a motion to approve the May 14th 2025 minutes? 00:00:42
I'll make that answer. 00:00:48
2nd. 00:00:50
All in favor. 00:00:52
Motion passes. 00:00:54
OK, any public. 00:00:56
Correspondence. 00:00:59
No, great. Nobody's here, so that's good. 00:01:01
We will move into the memo. 00:01:04
To town council, Did everyone have a chance to review that? 00:01:07
OK. And Charles, I'll let you. 00:01:12
Yep, so. 00:01:15
At our meeting last month. 00:01:17
We had citizens speaking during the public hearing for the. 00:01:21
Resilience plan and she brought up the. 00:01:26
Possible benefits to dredging Cove Creek as a way to address some of the storm water concerns. 00:01:30
And so. 00:01:40
Planning Commission had asked. 00:01:41
Staff to draft this memo to council noting that this. 00:01:43
Judging. 00:01:50
Consideration is noted in the comp plan which was recently approved and it was also in the previous iteration of the comp plan. 00:01:52
And. 00:02:00
There are maybe some. 00:02:02
Opportunities. 00:02:05
At this moment. 00:02:07
Or in this moment to. 00:02:09
Pull this dredging project forward along with some of the other dredging that's going on in the Intercoastal Waterway or is 00:02:13
planned for the Intercoastal Waterway. 00:02:18
And so it just seemed like an appropriate time and all that is outlined within this memo if there are. 00:02:22
Questions about. Happy to answer. 00:02:30
Or if anybody has some changes they'd like to make. 00:02:36
Stuff can keep it there on the backside down, or it can be. 00:02:40
They can use those people that are losing them. 00:02:43
I'll have to get carried off. 00:02:46
These other locations is that. 00:02:48
Peaceful thing. 00:02:50
I don't think that we have control over where they put the dredge spill. 00:02:52
It's certainly something that we can bring up if we do get. 00:02:59
To that point where we are going to do some dredging as to where that dredge spill will be. 00:03:02
Offloaded. 00:03:08
And, umm. 00:03:10
However, I don't think in. 00:03:12
Any circumstance is it likely that we will have? 00:03:14
Exclusive right to that dredge fill for our personal uses. 00:03:18
But. 00:03:22
It's worth. 00:03:24
Asking. 00:03:25
Yeah. 00:03:26
We could. I mean, it won't go far. It'll go to one of the spill islands right out there next to. 00:03:27
The Coastal Waterway. 00:03:34
Yeah, Rebecca, you may have some information on I know of. 00:03:36
It seems like I've read about at some point. 00:03:40
Regarding what's dredged. 00:03:43
Depends on where it comes from as to where they can put it because it has to be a certain quality to go on the beach, correct? 00:03:45
That's right, to go on the beach or to go back in the marsh even there is a method now called thin layer displacement where they. 00:03:52
Will dredge a channel and then. 00:04:00
Spray that sediment back on the marsh in a very thin layer to help that marsh build up in advance of rising seas. 00:04:03
And this would be the perfect. 00:04:12
Opportunity for that type of marsh restoration since. 00:04:15
The sediment is coming from such a shallow, recently silted system versus. 00:04:20
The deep bottom of the. 00:04:25
Of the Charleston Harbor where you know that hasn't that. 00:04:27
The silt tends to hang on to particles of. 00:04:31
Contamination in our water and the longer it's been in there potentially. So it is a good opportunity, however. 00:04:35
That whole process is. 00:04:42
A huge endeavor by the Army Corps. It takes 2 very different types of equipment to operate the dredging versus the thin layer 00:04:46
displacement. 00:04:51
And that would certainly have to be. 00:04:56
Under the charge of the arm of an Army Corps project. 00:05:00
But certainly we're investigating as the Army Corps is active right now in the ICW and otherwise. 00:05:03
That what they did down. 00:05:11
Marshall, David. That. 00:05:13
Similar to be tree nourishment, the pumping and piping. However to get the thin layer versus one sort of. 00:05:18
Underwater mound. 00:05:27
Takes special equipment so different from what they use for bee tree nourishment. 00:05:29
But similar concept. 00:05:35
I know they are behind IKEA now. 00:05:39
But who has talked to you? 00:05:44
We have been spoken. 00:05:48
To the dependable time events or. 00:05:49
Who's targeted and where? Where are we? 00:05:54
With regard to the ongoing project. 00:06:04
This is a request to have the Council look into. 00:06:11
Dredging of Coke Creek. 00:06:18
And so this is an initiation of. 00:06:21
Potential projects for the future. 00:06:24
And completely separate from what's going on currently. 00:06:28
At. 00:06:32
We have not engaged with the Corps of Engineers at this point in time, no. 00:06:37
This is sort of starting. 00:06:42
Yes. 00:06:45
Something that Council may want to consider given. 00:06:51
The storm water projects and the lack of public access, well, public access access is definitely diminishing back there, say from 00:06:55
the kayak launch. 00:06:59
And so forth. So that's. 00:07:04
What? Umm. 00:07:07
He prompted this by residents that spoke out about it. 00:07:08
And then something for council to consider since it's in the comp plan. 00:07:12
I was just curious if they had approached it at all. 00:07:16
You know, it's been receptive. 00:07:19
No, I don't think it's council takes an interest in this. They would ask staff to. 00:07:26
Try to coordinate some conversations with the. 00:07:32
Army Corps. 00:07:36
The Fort. 00:07:37
And any other. 00:07:39
Potential entities that we could. 00:07:41
Partner with to. 00:07:43
Create some. 00:07:45
What's the word I'm looking forward? Not symbiosis, but something similar to that word? 00:07:49
To get traction to move this forward. 00:07:56
Synergy, that is the word. 00:08:01
Thank you very much, Dave. 00:08:04
Yes, please. 00:08:08
Have a question? All paper motion pass. 00:08:19
Thank you very much. We'll. 00:08:26
With us. 00:08:28
Structures that. 00:08:33
Yes. 00:08:37
Beginning to touch on it, correct? 00:08:40
Today I'd just like to give you all a presentation about. 00:08:43
Some concepts regarding erosion control, control measures and structures and. 00:08:49
Kind of get. 00:08:57
Get your head strapped around what we could do, what the ordinance currently allows, and. 00:08:58
The direction that we're getting from our consultants with the sea level rise resilience plan. 00:09:05
And just kind of take it from there. 00:09:12
Not not trying to brush anything really, but wanted to get this started. 00:09:16
As we're wrapping up that sea level rise plan, and we should have some. 00:09:22
Concrete recommendations from them. 00:09:26
Very soon. 00:09:29
Umm. This is the, uh, current. 00:09:31
RC Area erosion control structure ordinance, section 2169. 00:09:36
In short. 00:09:43
It does not allow. 00:09:44
Erosion control structures, except those that were present when this ordinance was. 00:09:47
Adopted, uh. 00:09:52
And those pre-existing structures. 00:09:54
Are allowed to be repaired if they're not damaged by more than 50%. 00:09:58
And that's that's the current status. 00:10:03
With this ordinance. 00:10:06
Additionally, there's a. 00:10:09
A section in the Rs district. 00:10:12
This is the single family residential district that. 00:10:16
Prohibits erosion control structures. 00:10:20
So that that's our current framework that we have. 00:10:25
Operating under on the town. 00:10:30
In the town today. 00:10:32
Talk about erosion control structures. Oftentimes we're thinking about hardening the. 00:10:37
Coast to prevent. 00:10:44
You know, water from coming in or. 00:10:47
Land from going out. 00:10:50
Wanted to or both those things are the goals there. 00:10:52
But what we have on this? 00:10:56
Image in front of you is an example of kind of what. 00:10:59
What really happens when you have a seawall? 00:11:03
The wave action is reflected off of the sea wall and we tend to get erosion right at the base of the seawall. 00:11:06
And if. 00:11:16
If it were on a beachfront and we see it across the way at Breach Inlet, there's. 00:11:18
Erosion around. 00:11:24
One property that has a wall on the beach and. 00:11:26
You know, at certain high tides, you can't walk around the beach there anymore because there. 00:11:29
The ocean comes into the wall. 00:11:36
We have some examples on the back beach of where? 00:11:41
People have put. 00:11:45
A retaining wall. 00:11:47
Our or See well, however you want to look at it. 00:11:52
On their property and we see. 00:11:55
The adjacent property is eroding. 00:11:57
That behind it? 00:12:00
This is adjacent to this property. 00:12:03
Your answer on Dodson's property. 00:12:08
Yes. 00:12:10
That and that is something that I believe he would like to achieve for himself. 00:12:11
Similar situation to his neighbor. 00:12:18
Here's another picture of that location where we've got the erosion coming. 00:12:25
And from the. 00:12:30
Wave action that comes around here and it. 00:12:32
Pulls sediment back. 00:12:35
Creates kind of a churn. 00:12:37
This is on. 00:12:40
Off Thompson Ave. near Station 15. 00:12:42
That was built. 00:12:49
Problematically and I think 2021. 00:12:51
Yeah. 00:12:56
No it didn't. 00:13:00
Possibly could. 00:13:02
Then this just kind of gives you. 00:13:08
The basis for where we are today. 00:13:11
Now have this new. 00:13:14
Director of Natural Resources and Resiliency Rebecca, who's been here with us a year now, doing a great job. 00:13:16
And. 00:13:23
Helped me. 00:13:24
With this project here. 00:13:25
I'm presenting to you all today. 00:13:28
And just a quick update we've been through. 00:13:32
Phases one and two of this adaptation plan and. 00:13:36
You know, as of last month. 00:13:40
The consultants met with. 00:13:43
Our Commission and did an open house here to discuss where they're headed with the final draft and they'll be presenting that to 00:13:45
council. 00:13:49
In July, I believe. 00:13:54
From correct, yeah. 00:13:56
In there they have these 10 strategies that. 00:13:59
Are to address. 00:14:03
Creation of more resilient community and adaptations for sea level rise. 00:14:05
Two of them #4 and 7. Marsh Management and Protection and. 00:14:11
New and redevelopment of policies. 00:14:16
Are what I feel like. 00:14:19
This Commission should discuss in consideration of that RC. 00:14:23
2169 section of the ordinance. 00:14:27
What they were discussing with marsh management and protection is ordinance review, proposed revisions, promotion of living 00:14:34
shorelines and marsh stewardship activities. 00:14:39
Still needs to be fleshed out some more. And so we've kind of. 00:14:45
Taken taking the lead on. 00:14:49
Giving some. 00:14:52
Some meat on those bones. 00:14:54
Rebecca, do you wanna? 00:14:56
Speak to this a little bit. 00:14:57
Sure, yeah. 00:15:02
The marsh management aspect of the resilience plan. 00:15:05
Will be looking at ways to at once preserve. 00:15:11
The marsh and keep it. 00:15:16
Alive in a time. 00:15:19
When water is. 00:15:20
Rising more frequently and with those higher tides bringing rack and smothering. 00:15:23
The marsh as well, we're seeing issues in the salt marsh that. 00:15:29
Are new to the region so. 00:15:34
Here is a rendering from the City of Charlestons Land and Water Analysis that informed their comprehensive plan update in 2020. 00:15:38
That shows. 00:15:49
Some different arrangements of what the marsh can look like at the shoreline. 00:15:51
Where it is allowed to migrate inland and upland or. 00:15:57
Is held in place by a hardened structure and what some of the repercussions of that can be for habitat value. 00:16:03
As well as what the hardened structure does not solve. 00:16:12
With the water table rising behind that structure so. 00:16:16
Sort of a useful display of some of the. 00:16:20
Benefits and unintended consequences of different shoreline treatments. 00:16:24
And when we look at the alternatives between what we call in the industry green infrastructure, meaning more vegetated based 00:16:33
practices for erosion control. 00:16:39
Versus Gray infrastructure, think concrete. 00:16:45
Then there is a spectrum actually. 00:16:50
But there are aspects of the living green infrastructure that mimic the more traditional. 00:16:54
Bulwark robust approaches that we're used to seeing up creeks from. 00:17:01
Shoreline erosion control measures that. 00:17:07
Took place in the 70s and 80s and you know, we still have evidence of on our landscape so. 00:17:10
One of the key. 00:17:16
Aspects that is now permissible in South Carolina is a. 00:17:18
Oyster reef sill. 00:17:23
So that is immobile rock structure, shell structure of living oysters. 00:17:26
That breaks the wave energy before that wave, whether it's from boat wake or just a storm coming through. 00:17:32
Laps up against the shore. 00:17:40
Potentially otherwise eroding the marsh. 00:17:43
And oysters as a reminder. They can only attach. 00:17:45
If there's substrate already present. 00:17:50
So sometimes what that looks like Outback of Thompson, which I was. 00:17:53
I found interesting to realize was. 00:17:59
Someone had an engine block out in the marsh that they used as an anchor chain. 00:18:02
And that is now a cluster of oysters and an otherwise mud flat. 00:18:07
So not an ideal, but of substrate. 00:18:13
Fortunately, DNR has been working on this for years, and they've come up with some really good. 00:18:16
Options for substrate to get oysters started in a marsh. 00:18:22
And dissipate that wave energy. 00:18:26
To allow vegetation to fill in. 00:18:29
Here's an example from pretty close to home that's off Gold Bug Island. 00:18:32
An oyster, a living shoreline, an oyster reef. 00:18:38
Was put there at this sort of. 00:18:41
Eroding hairline of the marsh where wave. This is actually right by their boat landing, so you can imagine. 00:18:43
As boats were coming in along the ICW, that wave energy. 00:18:50
Was too much for the marsh to keep up with with these high high tides. 00:18:54
At the same time. 00:18:59
After installing this in 2016, if we go to the next site I believe we can see. 00:19:00
This is a project that The Nature Conservancy spearheaded. 00:19:07
And you can see that green line is where the marsh grass ended. 00:19:12
In 2016 before construction. 00:19:16
And the last time that they did a comprehensive analysis of this project. 00:19:20
It was all the way at that red line, so that's a lot of marsh to regain in a short few years. 00:19:24
And all because that. 00:19:32
Oyster reef has dissipated the wave energy. 00:19:33
Oh great. 00:19:40
And then just to sort of. 00:19:42
Give you a schematic of how. 00:19:45
And why this works? 00:19:47
The oysters as well as keeping the waves from eating up that. 00:19:48
Bank of the salt Marsh. 00:19:52
Are also slowing the water down enough that new sediment has a chance to drop out and rebuild. 00:19:54
That grade? 00:20:01
Does create. 00:20:03
Not just give the vegetation a chance to reestablish, but raises the grade of the marsh where it has been. 00:20:05
Eroded and has the bonus of providing habitat. 00:20:12
Looking at the spectrum again of. 00:20:20
Kind of green to Gray infrastructure. 00:20:24
You can see that in the top right where it's just vegetation and nothing basically if we did nothing. 00:20:27
And it was just vegetation up to the water's edge. 00:20:35
We would expect to see further. 00:20:39
Degradation. So doing nothing is not a great option. 00:20:41
Doing the traditional method of the 1970s, installing sheet piling. 00:20:46
Into the marsh. 00:20:52
Doesn't do us any favors either, and perhaps is a worse risk down the line. 00:20:53
When Gray infrastructure fails, it tends to do more harm. 00:20:59
Then it was intended to preserve all those years so when green infrastructure quote, UN quote fails. 00:21:04
When something blows out, the repercussions typically are very minimal. It will. 00:21:13
Heal itself before the next storm. 00:21:18
With Gray, infrastructure collapses, if that. 00:21:21
Erosion that scour at the base or around the edges. 00:21:24
'Cause that wall to collapse. 00:21:29
Then the land would lose a lot of soil all at once. And you would. 00:21:31
Have to move the new wall. 00:21:36
Much further inland, so really not. 00:21:39
And maybe in the short term seems efficacious, but in the long term? 00:21:42
Does more harm than good. 00:21:47
We see with the oyster sill method. 00:21:49
That you do build up. 00:21:53
More of the transition area and therefore the buffer. 00:21:55
Between uh. 00:22:00
Residential or whatever the upland property is. 00:22:02
And the water's edge. 00:22:05
So it turns out it also happens to be much more affordable, so considering. 00:22:13
Really long lengths of shoreline. 00:22:20
Where folks would want to band together potentially to do a project like this. 00:22:23
The distributed cost of management, maintenance, installation. 00:22:29
For plant and or natural process based restoration. 00:22:33
Is typically, you know, an order of magnitude lower than. 00:22:38
The cost of a more heavily engineered or hardened. 00:22:42
Erosion control measure. 00:22:47
Next, we're going to talk a little bit about the. 00:22:54
Policies. 00:22:58
That we might wanna address. Use to address these concerns. 00:22:59
And there are a number of different ways that we can. 00:23:06
Adapt. 00:23:10
This is kind of a. 00:23:12
Sheet that shows things from green infrastructure. 00:23:14
Efforts all the way up to elevating roads. 00:23:19
Creating uh. 00:23:23
Drainage basins. 00:23:24
Elevating houses. 00:23:25
Possibly even relocating homes to higher ground. 00:23:27
Just kind of gives you the. 00:23:31
Idea of. 00:23:33
All the different things that we can do to combat sea level rise. 00:23:34
On the local level. 00:23:38
And this is. 00:23:42
From Florida. 00:23:44
And what they've done is. 00:23:46
Projected where sea level rise is going to be. 00:23:49
And. 00:23:52
Created this. 00:23:53
Green infrastructure area. 00:23:55
To allow the marsh and the. 00:23:58
To migrate to have. 00:24:01
Some space. 00:24:03
For the ocean to rise without. 00:24:05
Negatively impacting. 00:24:08
The residential or. 00:24:10
You know the park. 00:24:12
Behind it in this case. 00:24:14
And as you can see these. 00:24:18
Plant materials that. 00:24:21
Really do well in this habitat, tend to stay low, they don't. 00:24:24
Typically obstruct the view corridors that are. 00:24:29
You know, highly valued. 00:24:33
Aspects of people's property here. 00:24:36
This slide is just to show you. 00:24:40
Where we do have existing. 00:24:43
Bulkheads. 00:24:47
When they do need to be repaired and they ultimately all will need some repairs as shown on that slide, the cost? 00:24:49
For maintenance, there is a maintenance cost involved with these. 00:24:57
There are options to. 00:25:01
Kind of create this intertidal shelf which will add habitat along the. 00:25:04
Head and. 00:25:09
Provide a little bit of. 00:25:12
Protection from scouring. 00:25:14
And, umm. 00:25:16
Pretty much make the bulkhead last longer and. 00:25:19
Less of a detriment to the ecological benefits that. 00:25:23
Or the ecological. 00:25:29
Aspects of the. 00:25:31
That was there. 00:25:32
These are a few. 00:25:36
Uh. 00:25:39
Books or? 00:25:41
Reports that have been done that. 00:25:43
Provide some additional. 00:25:46
Information about. 00:25:48
Shorelines and. 00:25:51
Creating buffers along shorelines and the benefits of them. 00:25:52
These are all local. 00:25:57
Documents from. 00:26:00
DNR. DACC. 00:26:02
We can share this bibliography with you all. 00:26:05
And these are just a couple of examples of. 00:26:11
Ordinances in other places that. 00:26:16
Have buffering requirements which are kind of. 00:26:21
Kind of like a set back but. 00:26:25
In addition to being a set back, there's. 00:26:27
Vegetative requirements, typically within buffers. 00:26:30
In Georgia, they have. 00:26:34
A 50 foot requirement. 00:26:36
So that that would be a natural area and you're allowed to have. 00:26:38
15% of it be an impervious path to get out to say a dock or. 00:26:43
Some other recreational use of the. 00:26:49
Water beyond your property. 00:26:52
North Carolina has a similar. 00:26:56
30 foot buffer with a 20 foot additional area where they don't allow pavements or structures. This is. Along streams or ponds this 00:27:01
is. 00:27:05
Not necessarily our. 00:27:10
Environment, but it does have the same kind of. 00:27:12
Gives you a cross section of kind of what. 00:27:15
Thinking about. 00:27:19
And then closer to home. 00:27:22
Right along the Ashley River in North Charleston, they have 100 foot shoreline buffer where they. 00:27:25
Don't allow any development and you can see the result is. 00:27:31
Looks wild. 00:27:35
Along the Ashley. 00:27:37
Here is a schematic that. 00:27:42
That as you go up the Bank of the. 00:27:47
Marsh the different species that do well in those habitats as we go from. 00:27:52
The water to the oyster bed. You got your marsh grass spartina. 00:27:58
Then some of these. 00:28:03
As a marsh indicators the sea oxide Daisy. 00:28:05
Seaside Goldenrod. 00:28:09
And then as you get to the higher ground. 00:28:11
The live votes. 00:28:14
Start that. 00:28:15
Kind of based on all that thought. 00:28:22
We've got some ideas that we want to share with you all today. 00:28:25
From staff perspective. 00:28:28
The first thing we'd recommend is that we maintain the prohibition for erosion control structures in the. 00:28:32
Recreation and Conservation District. 00:28:39
And justice add language to that section that. 00:28:43
When these. 00:28:48
Structures need repair. 00:28:50
That they're required to do some intertidal shelf. 00:28:52
Type treatment or add. 00:28:55
Living Transition. 00:28:58
Transition zone additions which are. 00:29:00
Essentially like. 00:29:03
Imagine like. 00:29:05
Putting. 00:29:08
Ornaments on the wall. 00:29:12
That would allow oysters or other. 00:29:15
Mollusk type animals. 00:29:20
In the ocean to latch on to to create. 00:29:22
Life along that wall surface. 00:29:26
And then in the Rs district. 00:29:30
Create a natural barrier along the critical line that could be a buffer. 00:29:34
Established between the critical line and a land elevation of about a foot and a half above the critical line. 00:29:39
I've got a slide that kind of shows this. 00:29:46
Might be easier just to look at the slide. 00:29:49
Talk about this. 00:29:52
So here's our. 00:29:55
Down here on the blue line. 00:29:58
And what what what I was? 00:30:00
Just basically saying, is this first foot and a half above the marsh as we grade up into the higher land? 00:30:02
That that be maintained as a buffer area, not putting a. 00:30:09
A number like a 30 foot buffer or 50 foot buffer or 20 foot buffer but. 00:30:13
Basing it on how the topography changes and where that topography rises a foot and a half above the critical line that would give. 00:30:19
The Marsh. 00:30:27
A chance to migrate it would createspace for. 00:30:28
Sediment to. 00:30:32
Be pulled out of runoff before it goes into the marsh. 00:30:35
And infiltrate into the soil. 00:30:40
And other benefits to that. 00:30:42
Yeah, I think one that we have failed to touch on yet is the pollution removal from the upland. If you have storm water running 00:30:44
off of the roads, everyone's little oil leaks have accumulated in that water having. 00:30:51
A little bit of a vegetated buffer has been shown to pull out like 50% of pollutants in storm water runoff. 00:30:59
In just a very small buffer strip. So that's one benefit of having that. Another is, you know, a foot and a half higher than high 00:31:08
tide happens pretty frequently. 00:31:14
So if we think about making sure. 00:31:21
That people don't have things in that area that could get damaged. 00:31:24
A frequent storm that we have. 00:31:29
Think also preserves that private property value giving. 00:31:31
The elevation of water, a little room to breathe without causing disturbance. The plants can handle it. 00:31:35
And then another sort of Co benefit just being. 00:31:43
The habitat and the fact that anything that salt tolerant. 00:31:48
If you picture like how the dune grasses are. 00:31:53
You you don't really get height with those vegetation, so I think it would also be very aesthetically pleasing. 00:31:57
To have a buffer of what's flowering right now, which is that yellow sea oxide Daisy. 00:32:04
It would be an easy thing to. 00:32:11
For people to maintain. 00:32:14
And keep looking good. 00:32:16
And then once you. 00:32:20
Get above that foot and a half we would. 00:32:21
We would propose to allow. 00:32:23
About a foot and 1/2. 00:32:26
A non hardening erosion control measure. 00:32:28
Think like the enviro lock. 00:32:31
Sandbags that have been put in at the Cove Inlet Bridge project, something like that could be stepped. 00:32:35
Increasing. 00:32:43
To allow. 00:32:44
In these areas where we do have really low elevations on some of these lots to allow them to gradually. 00:32:46
Build their elevation. Build their. 00:32:54
Property up to where the building pad is set at 7 1/2 feet above sea level, which? 00:32:57
Predictively. 00:33:05
Will be outside of extreme tidal events. 00:33:07
50 years from now still. 00:33:11
So that would. 00:33:13
Creative. Resilient. 00:33:14
Situation for those homeowners, it would. 00:33:15
Be a change in the ordinance because some of these properties are at 5 feet, so this would be bringing in more than a foot of fill 00:33:19
in certain circumstances. 00:33:23
Really. 00:33:30
Property. Adjacent schools. 00:33:31
I think that we would be looking at this. 00:33:36
More broadly than that. 00:33:42
Because there are other properties that are sitting and so. 00:33:44
You know, on the other side of the street from. 00:33:48
Like the properties on Osceola that are across the street are also very low in some cases. 00:33:52
One thing that we kind of tossed around a little bit and I'll go back to the previous slide. 00:33:59
Was. 00:34:05
Perhaps this? 00:34:06
We put parameters in place and. 00:34:09
Put this as a special exception. 00:34:12
Such that. 00:34:15
Bound specifically to these. 00:34:18
Concepts, but that if there is a. 00:34:20
Property that is experiencing hardship because it is of low elevation lot. 00:34:23
That we could take it to the. 00:34:29
BZA and they could get a special exception to elevate to the seven and a half feet and. 00:34:31
There would be kind of guidelines in place for. 00:34:37
What that elevation looks like that the slope of the lot? 00:34:42
Couldn't be more than. 00:34:46
5% potentially and. 00:34:47
These erosion control structures no more than 18 inches on the property to hold in that. 00:34:50
Fill dirt that would bring the elevation of the property up. 00:34:55
It would make sense if one. 00:34:59
Resident did it that adjacent residents would have to do it as well or else it's going to cause. 00:35:01
Interesting. 00:35:10
Well. 00:35:11
These uh. 00:35:12
And we did some analysis on. 00:35:14
Elevations of lots around the island. 00:35:17
There are. 00:35:20
Most of them. 00:35:23
Are along the. 00:35:25
Waterfront for sure. 00:35:26
And they're not. 00:35:28
Too many lots that would need more than a foot of fill to get to a 7 1/2 foot. 00:35:31
Building pad. 00:35:37
And this would be the responsibility of the homeowner. 00:35:39
To elevate their property, correct? 00:35:43
Yes. So it would be the homeowners expense I guess. 00:35:46
The way I'm thinking is if you just have two homeowners that want to do it and that can afford it, and maybe some other neighbors 00:35:50
can't afford it, and what is that going to create? 00:35:55
So one of the things that's also consideration here is expanding the storm water management plans. 00:36:00
Adding some metrics into that that would. 00:36:07
You know engineering can solve a lot of problems. And if it's a. 00:36:11
Problem of. 00:36:16
5000 square feet of runoff. 00:36:19
From storms. 00:36:22
I think that there are engineering solutions to manage that on those properties. 00:36:24
And if if somebody's coming and wanting to do that elevation, then that. 00:36:30
You know that would our existing stormwater requirements would be. 00:36:35
A part of that project and they're. 00:36:40
This could be expanded a little bit. 00:36:42
Are there grants available? I'm just sorry, Laura, it just worries me creating an ordinance. 00:36:44
That some you know. 00:36:50
That some homeowner homeowners will take advantage of immediately, but then others. 00:36:54
Are not going to be able to afford to. 00:37:00
And then? 00:37:01
It's going to create problem more problems with their property, especially when I'm considering. 00:37:02
On the Creek on both sides where it floods of the island. 00:37:08
I don't know. That's yes. And that's what I always thought about when it comes to a bulkhead. And you can clearly see that 00:37:13
happening on the beach and the photos that you saw that. 00:37:18
Where you have the bulk ahead. 00:37:23
The properties adjacent. 00:37:25
Eroding so anytime you build something up it. 00:37:27
You know the water is going to go where it can. 00:37:30
I just think that's something we have to be. 00:37:34
Pretty careful with. 00:37:36
Yes. Umm. 00:37:37
But like you said, engineers can solve just about anything. 00:37:38
So my question was, I know we currently have ordinances in place that require. 00:37:42
Homeowner. 00:37:47
To maintain the water that is collected on their property, right? So if they were to build their property up by more than a foot. 00:37:48
Then wouldn't they also still be required to? 00:37:57
Figure out how to maintain that water on the property and prevent it from. 00:38:01
Draining off into someone elses property so I think. 00:38:06
Well, but if the water is coming from. 00:38:09
Creek, you can't really manage where that water's. 00:38:11
Coming. You see what I'm saying? It's if it's not flowing often to someone else's property, but if it's flowing back into the 00:38:15
Creek, I think that would be the intent of this. 00:38:20
I think the intent is on the Creek side is so that you have a little bit of a buffer to keep the, yeah. 00:38:25
King water from coming in. Yeah, so. 00:38:32
If it's coming from. 00:38:35
Interior, Yeah, we're talking about water coming up. 00:38:38
On this property. 00:38:41
And essentially the. 00:38:45
Creating this buffer area along it would be. This property would be. The next property would be all the properties that would have 00:38:48
that buffer area. 00:38:51
Associated so there would be. 00:38:55
Space on anyone of these properties between the critical line and a foot and a half above the critical line where? 00:38:59
Migration of the Marsh. 00:39:08
Influx of high tides can come in. 00:39:11
And go out without affecting any of the properties in a negative way. 00:39:14
Can I ask a question? Yeah. 00:39:20
The oyster sill, the reef that you you showed the example of that in three years time. The grass. 00:39:22
Greatly increased. 00:39:29
That that oyster sill was pretty substantial and pretty high. 00:39:30
When those strategies be the strategies that would be the lead strategies on the Creek side of this. 00:39:35
Island. Is that what we would be using as oyster sills or Reeves? 00:39:40
And how high would they be and. 00:39:45
That kind of that's sort of my first question. I think they would be. 00:39:48
You know, on an individual basis. 00:39:54
Whether or not it would be appropriate, some areas of the island it would be more appropriate than others. 00:39:57
One thing that we discussed was down at. 00:40:05
Down at the end of the island where we're. 00:40:10
Discussing. 00:40:14
Doing a. 00:40:16
Pocket Park here at the end of Metal St. 00:40:18
That there may be an opportunity to do. 00:40:22
A living Shoreline demonstration project here, if that. 00:40:25
All pans out. 00:40:29
That this would be a good candidate location. 00:40:30
4/1. 00:40:34
And that you know. 00:40:37
Most of these properties that are already hardened along the shore would not be good places to propose one, but. 00:40:39
Back along here where we had Marsh. 00:40:47
These could be places that would be. 00:40:51
Good good locations for. 00:40:54
Potential oyster? 00:40:57
And those oyster reefs wouldn't really interfere with the ability of the owners to use their. 00:41:00
Their docks and their boats, they could still. 00:41:05
Yeah, it would be. They should land there. It would be boat and walk in. 00:41:08
The inland it would be a shore word of those. 00:41:11
Boating locations you wouldn't interfere with their ability to enjoy No, and it wouldn't be hot. There wouldn't be high enough to 00:41:14
affect the. 00:41:18
The walkways and then. OK, thanks. 00:41:22
Yeah. 00:41:24
In that particular area we really in. 00:41:31
It is. 00:41:35
The marsh is growing in that area of the island. 00:41:36
Silting in. 00:41:41
Yeah. 00:41:44
Let's see if there's anything else that we missed in here. 00:41:49
Some other things that we. 00:41:53
Thought were worth considering as we talked about this we're. 00:41:55
Um, redefining the term pervious. 00:41:59
What would a pervious material is in the definitions on the island? 00:42:02
And then? 00:42:09
Possibly. 00:42:10
You know this. 00:42:11
Creation of a metric for what is a high risk or a low elevation site that would be eligible for. 00:42:13
A special exception to do this. 00:42:21
Increased fill work. 00:42:24
And then, then. 00:42:28
More of the inland areas of the island. 00:42:29
Where they, where they're some, some lots are in bowls essentially. 00:42:32
Creating opportunity for them to elevate those properties so that the building pad would be at least 6 inches above the crown of 00:42:39
the road. 00:42:43
To because as our stormwater master plan is implemented. 00:42:48
More and more stormwater will be. 00:42:53
Captured in the right of way and. 00:42:56
Brought to the out falls. 00:42:59
For this for you know. 00:43:02
To leave the island. 00:43:05
Having these bowls in the island. 00:43:07
Is a detriment to that plan because. 00:43:10
The water is going to go to the. 00:43:13
As opposed to into the stormwater system and even if it's. 00:43:14
Going off of your property and your property into the storm water system. But Galley's property is lower. 00:43:18
A lot of it's going to make it to her property instead of into the stormwater system. So that would be. 00:43:25
Another thing to consider as we're talking about. 00:43:30
This whole issue. 00:43:32
And then perhaps defining what a landscape wall is. 00:43:36
So currently. 00:43:40
We uh. 00:43:42
Allow them as a policy, but it's nothing in the ordinance that allows them. 00:43:43
And defining that in such a way that it's different from a non hardened erosion control structure, defining both of those features 00:43:50
so that there's clarity on what? 00:43:54
Is allowed because. 00:43:59
What we see. 00:44:01
And this. 00:44:03
Sort of an example. 00:44:06
But umm. 00:44:08
Not a not the right example because it was for the wrong. 00:44:08
Wasn't really. 00:44:12
Permitted. 00:44:13
This is being considered. 00:44:17
By the homeowner as a. 00:44:19
Landscape Wall. 00:44:22
But what it really is is a. 00:44:24
Erosion control structure. 00:44:27
So it's. 00:44:31
Taking advantage of that. 00:44:33
Term and utilizing it right at the property line. 00:44:35
To create. 00:44:40
A hardened shoreline. 00:44:43
Yeah. 00:44:46
Definition. 00:44:48
Yeah. 00:44:54
I'll go into a little more detail. 00:44:58
Currently. 00:45:04
Pervious materials are defined as any material. 00:45:06
Through which water can be easily absorbed or passed at a minimum infiltration rate of two inches per hour. 00:45:09
Such as, but not limited to grass. 00:45:17
Uncompacted gravel. 00:45:20
Shell and crushed stone. 00:45:21
When you put down. 00:45:26
Uncompacted gravel or uncompacted shell and crushed stone is the driveway. 00:45:30
It gets compacted. 00:45:36
It ceases to be pervious. 00:45:38
Grass, I mean. 00:45:42
Turf grass is somewhat A pervious surface, but. 00:45:46
Not really like. 00:45:51
What we're if we're asking for somebody to. 00:45:53
You know, put down pervious surfaces. That's not. 00:45:57
What we're really looking for and then. 00:45:59
When we talk about this minimum infiltration rate of two inches. 00:46:02
Per hour. 00:46:07
Yeah. 00:46:13
And it doesn't. 00:46:14
Really match with real world conditions like their. 00:46:17
Engineers tend to push back on this and say. 00:46:25
What do you mean? 00:46:28
This doesn't make sense to me so. 00:46:29
So the papers are in. 00:46:31
So it. 00:46:35
Those can be so if they've got gaps in them that are maintained. 00:46:37
And then below they have the. 00:46:42
Storage basin that's filled with rock that has lots of space in between the rocks. 00:46:44
That works. 00:46:50
Can be a legitimately. 00:46:53
Pervious surface. 00:46:55
Basically. 00:46:57
I just think it could be better. 00:47:00
Would you agree? 00:47:03
A lot better. 00:47:04
Yeah. 00:47:06
What would be better? 00:47:10
Yeah, we have. 00:47:12
Really good data from. 00:47:15
The US Department of Agriculture on runoff. 00:47:18
Ratios How much rainfall goes into the ground after traveling over. 00:47:22
A forested area all the way down to concrete. Concrete, as you can imagine. 00:47:28
100% of the precipitation turns into runoff or ends up in a pipe somewhere. 00:47:34
Forested areas in the Francis Marion we have numbers that suggest 80%. 00:47:40
Of precipitate of rainfall. 00:47:47
Will go into the ground. 00:47:49
20% ends up in a nearby stream. That's huge. That's a lot. 00:47:51
Lawn. Lawn is somewhere more like. 00:47:56
40 Excuse me? 00:48:02
I switch the ratios on you because I talked about 100% for. 00:48:03
Picture 20% as the ratio for the forest. 20% of that rainfall turns into runoff in the stream. 00:48:08
For LON, that number gets up past. 00:48:15
50% in the 60s. 00:48:19
So going from only 20% of rainfall going into a Piper tidal Creek that can only carry so much to 60% of that precipitation is a 00:48:23
huge jump. 00:48:28
And then just thinking about these more engineered systems with. 00:48:34
Even a gravel basin with lots of poor space where that water could move fast down into the sandy soil below. 00:48:39
It can't if it's silted in. 00:48:47
So just also recognizing some of the maintenance burdens of these engineered systems and how to maintain. 00:48:49
The efficacy of those structures overtime is an important consideration for keeping something pervious. 00:48:58
So it's actually functioning. 00:49:05
For the homeowner and for their neighbors sake for. 00:49:07
Years after construction. 00:49:11
But then also thinking with perviousness. 00:49:15
That it's not just about storm water, it's about the ability of that system to filter out contaminants before they end up at the 00:49:19
outlet at the marsh. 00:49:24
And with this ordinance in particular, I think we started to. 00:49:31
Consider perviousness. 00:49:36
Because of other municipalities that have. 00:49:38
Created these buffer programs is primarily to keep sediment out of creeks and if you've been to the Upstate and you've seen the 00:49:41
kind of erosion that happens and. 00:49:45
The way that title or excuse me, that streams will get silted in with orange clay or ditches will get silted in. 00:49:50
That's the primary reason why. 00:49:57
These other immune, excuse me, these other states, Georgia and North Carolina have put these. 00:49:59
Mandatory buffer requirements and. 00:50:05
That acting as a pervious surface is not just allowing water to get through, but it's also allowing. 00:50:07
The trapping of various contaminants, fertilizers from lawns, the oil leaks from cars, etc, etc. 00:50:15
To get locked up in the soil. 00:50:22
And filtered by plants which are actually really good at breaking down oil based. 00:50:25
Contaminants like fertilizers and actual. 00:50:31
Car oil. 00:50:34
What else about perviousness? 00:50:37
Or why? 00:50:42
You know, I think you touched on it a little bit, some of the. 00:50:45
Practices that we're seeing with. 00:50:50
Certified stormwater management plan that has pervious surfaces. 00:50:53
Is that? 00:50:58
They will collect the rain water. 00:51:00
And get it to. 00:51:04
The Street. 00:51:06
As quickly as possible. Not really infiltrating it into the lot, not really recharging the ground. 00:51:08
It's not really being. 00:51:14
Pervious in the sense that there's absorption occurring. It's pervious in the sense that. 00:51:16
They're directing the flow off the property into the proper channel that we allow. 00:51:22
Which in some cases works. In some cases our stormwater system doesn't work today. 00:51:27
So it really just goes across the street to the. 00:51:33
Low neighbors lot. 00:51:37
Anyway. 00:51:42
That's a lot for y'all to chew on. 00:51:43
So I guess my question is. 00:51:46
And thank you this there's a lot of thoughtful. 00:51:49
Recommendations here that I think we really ought to take a closer look at is the next step then. 00:51:52
For y'all to. 00:51:57
Carefully look at what zoning ordinances or other ordinances that we have. 00:51:58
On the books and figure out which ones we would want to amend to try to adopt these and then bring them here for. 00:52:04
More thorough discussion. Is that the next step? 00:52:11
If if. 00:52:14
If you are. 00:52:15
On board, I was thinking maybe that. 00:52:17
We'd take a month, chew on what has been. 00:52:20
Yes, given to you. Y'all can give you a copy of this presentation today. 00:52:23
And you know, come back to us and say, yes, this. 00:52:29
Something that we want to work on doing and this is not. 00:52:33
Because I think, you know, the devil's in the details and, you know, as we talked about, you know. 00:52:39
If we're if we're allowing one property owner to raise their, you know, left their elevation a foot. 00:52:44
What impacts does that have to an adjoining neighbor? 00:52:50
You know, so I think. 00:52:54
You know, once we dig into some of the details, it's going to be easier for us to have an informed. 00:52:55
Discussion about whether or not we would really recommend that or not. I mean, on the surface it looks like motherhood and apple 00:53:00
pie. 00:53:03
You know, a lot of these are, you know, because it all sounds like great stuff. But then I think when you dig into it, we'll have 00:53:06
to understand what. 00:53:09
Some of the ramifications are of some of these things. 00:53:13
That makes sense. 00:53:17
The staff recommendations that you had up there are all. 00:53:20
All of those recommendations from the consultants are. 00:53:23
No, these are. 00:53:28
From uh. 00:53:31
The two of us. 00:53:32
Based on these. 00:53:34
Kind of broad brush ideas that we've gotten from the consultants which are. 00:53:37
You know, review existing codes and ordinances compared to other coastal communities. Are there places for improvements? Building 00:53:43
footprints? Vegetated buffers? 00:53:47
And then the other. 00:53:52
Piece that they've given us so far is, you know, ordinance review, proposed revisions, promote living shorelines, marsh 00:53:54
stewardship activities. So we took those. 00:53:58
High level. 00:54:03
Thoughts and kind of ran them through our ordinance and came up with these recommendations. So will that. 00:54:04
Will the consulting company come up with their own set of recommendations? 00:54:10
Yes. And those will be in a report presented next month. So it's also a very timely in the sense of. 00:54:15
Having this perspective before that resilience plan is published. Reviewing. 00:54:23
Their final? 00:54:29
Recommendations. Thoughts, ideas, Considerations, Infographics. 00:54:30
It'll be a good visual communication tool, I imagine. 00:54:34
To be able to. 00:54:38
Process the two together and come back with. 00:54:40
A lot of ideas getting at is the information from them is what? 00:54:45
Going to drive this solely correct. 00:54:49
If y'all wanted to. Only if you wanted to, Right, Right. Right. Yeah. I mean, I know that it's probably a lot, but I mean, there's 00:54:56
not someone in left field saying, Oh well, let's do this. And it's not necessarily a thought or recommendation by the consultants. 00:55:03
It's actually just something someone wants. You see, You understand what I'm saying? 00:55:10
I think that. 00:55:17
We'll we'll find that this is similar to what their. 00:55:19
Going to be proposing. 00:55:23
We've talked to them about these ideas and how. 00:55:25
That they they were on board with where where we're directing. So we will see that in July or August. 00:55:31
OK, Yeah, yeah. And and. 00:55:38
You know, to the you know, we've taken a year to get to this point. 00:55:41
We're not, we're not in the nightclub. 00:55:45
Race to the finish line. At this point we right I want to take. 00:55:50
Whatever time we need to do it right. 00:55:55
Get it right? 00:55:57
One in one shot. 00:55:58
Can I ask so the island is what, 3 miles long? 00:56:00
3/3. 00:56:05
Our side umm. 00:56:07
Do we have like? 00:56:10
Enough space between that we would say this doesn't maybe the. 00:56:14
You know certain. 00:56:20
What you just need to do in this spot? 00:56:21
Where is this spot which is building up too fast? 00:56:25
Is there any? 00:56:29
Establishing. 00:56:31
I think that when we look at. 00:56:35
Recommendations. 00:56:38
They may be tailored to different parts of the island differently because there are different circumstances when you're at the 00:56:40
edges of the island versus the central part of the island. What's happening? Yeah, geomorphically is. 00:56:48
Potentially, yes, some zonal. 00:57:00
If you go back to their. 00:57:03
10 strategies, just the broad. Yeah, the broad one. 00:57:04
Yeah. So what else will come into play that we didn't highlight here is residential scale nature based solutions and those will 00:57:08
look very different. 00:57:12
In the middle of the island and they will on front beach, then they will on back beach then they will. 00:57:17
At ends of the island on back beach, from the middle of the island on back beach. There's a lot of nuance and little micro 00:57:22
climates to the. 00:57:25
Different situations and positions on the island. 00:57:29
And the team has spent a lot of their. 00:57:33
Time and work the consultants have on. 00:57:36
Modeling. 00:57:39
How different interventions, how effective they are at reducing flood impacts given different soil conditions. 00:57:41
Elevation types. 00:57:49
So they have some really amazing maps that. 00:57:50
Do that are land based and physical process based. 00:57:53
That kind of. 00:57:58
Highlight different. 00:57:59
Parts of the island. 00:58:01
That would be the most effective place for different. 00:58:02
Solutions and not just talking about. 00:58:05
Living shorelines, but any sort of. 00:58:08
Stormwater control measure you can think of. Where would that work the best? 00:58:11
Seems like they can make a drone video from the talking about now and just show everybody. 00:58:15
Each part. 00:58:21
I'm wondering as possible the other question is 1963 and then. 00:58:22
What are you trying to show us in this? 00:58:27
Compared to the last time sale that actually came from the consultants presentation, we were just using it to highlight their 00:58:30
bullet point strategies. 00:58:35
And those maps are aerial views of the island. 00:58:40
In 1963. 00:58:44
There was number marsh there at the Cove. It was open water. All of that marsh has accreted. 00:58:47
Um, probably as a major, majorly because of as a response to. 00:58:55
The **** that is the Causeway and it's slowing the flow of water and allowing that silt to settle out. 00:59:00
So just to show that this marsh is quite new, it is accreting. Sullivans is really lucky for all the accretion that we get. 00:59:07
And and yet. 00:59:16
Yeah, just that there's an opportunity with that accretion. 00:59:20
To build more sponging of floodwater, more buffering from wave action when we do have storm surge issues or wind from the back of 00:59:24
the beach. 00:59:29
So just highlighting that as an asset that. 00:59:35
Silting in perhaps causes some inconveniences with access to Cove Creek, but otherwise? 00:59:38
It's actually really lucky for a resilience perspective. 00:59:44
Thank you. 00:59:49
This would be stupid question, I'm saying. 00:59:53
Do we give any thought? 00:59:56
Today. 00:59:57
There will be. 01:00:00
There were conversations with SCDOT. 01:00:05
And with McCormick Taylor one of the team. 01:00:09
And. 01:00:13
They will be focusing one of their strategies. 01:00:14
On the Causeway. 01:00:18
Yeah, last December it was. 01:00:25
About a foot from hitting the. 01:00:27
The only thing I was told was they were supposed to put me in a lot more pipes. 01:00:29
Gary, let's come over, you know. 01:00:33
Right now it's just a war way itself. 01:00:36
Yeah, that's a it's a pretty complicated. 01:00:58
Endeavor. 01:01:03
It would change things. 01:01:06
Yeah. 01:01:09
That is a best practice. 01:01:23
It's a lot more expensive to do. 01:01:25
And it doesn't happen in a lot of these roadway projects. It's one of the things that gets cut. 01:01:28
Yeah, yeah. 01:01:42
We have our Commission for us. 01:01:49
No. 01:01:53
Town Updates. 01:01:59
Don't think so. 01:02:01
Motion to adjourn. 01:02:04
Second, all in favor? 01:02:11
We are adjourned. Thank you. Yes, Sir. 01:02:17
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