Stormwater remediation and erosion control recommendations

[Deenie]

Hello all I am new to this site. I truly appreciate the opportunity to share my delemma and gain insight from your posts.

I have included a picture of our office park to get an idea of what I am talking about.

Project is an office park surrounded by culverts, where the office park is the lowest lying property of its 4 neighbors.
Office park has 4 nieghbors.

Property on the East side of the park is all conversation land with a large pond in the middle.
Property on the South side of the park is the main highway
Property on the West side is a large storage building.
Property on the North side is a parking lot with storage containers belonging to the same owners of the storage building West of park.

Trying to paint a picture, Office Park sorrounded by a moat on 3 sides when it rains. The South side of park has no culverts. The main Road has sewers that align the road.

During storm season Culverts are full of water due to the extrodinary amount of storm runoff from the hurricanes.

Our retention pond which is on our East side of the park has overflowed to the North Neighbors retention pond. Their pond has overflowed due to the excess storm water coming from us and conservation property to the East. It seems as though the water is flowing from south to north

The buildings in the park are eroding with the culverts being so high.

Looking for recommendations, comments, advice on the following:

Can dredging the culverts and ponds be a long term solution? What other ideas about water remediation is possible if you are limited with space.

A retaining wall can help with the building erosion, would concrete, wood, rubber or plastic bags with sand be a recommenation as to what the wall should be made, length and width?

Any other ideas. thoughts, comments are welcome I have read so much hoping to get clarifcation and an Education. Along with a solution.

 

[zelgar]

Unfortunately, your attachment doesn't clearly show the pond. Based off the information, I was able to look at it through Google Maps & Street View. It looks like there is a very small triangular pond in the corner of the property behind the dentist office. Could this pond be extended to run E-W along the northern property line. This would get you a bigger pond, but I doubt that anything could be adequately sized for dealing with hurricanes. It appears that there is a culvert only because there is a lighting for the parking lot. Removing the culvert and replacing with a channel may allow for faster flow of water from the south to your detention pond.

 

[swazimatt]

Could the pond be deepened to increase capacity?
I would expect that your stormwater culverts are designed for smaller storms (here it is the 10yr 10min storm) and anything above that would flow overland. The same would apply to the size of the pond. If the culverts are silted up then removing that would obviously increase capacity and then I would try and work out where the silt is coming from and try to prevent it silting up again - silt in large quantities normally comes from somewhere upstream eroding

I would imagine building a bund or swale to direct runoff away from the eroding bank would be a cheaper solution than a retaining wall. you could possibly also riprap the bank to prevent erosion (difficult to tell without more info)

Alternative option that is more expensive is to have stormwater detention (possible soakage to ground?) under the car park using something like triton vault https://xerxes.com/hydrochain-storage-and-inflitration/

 

[Pinwards]

This appears to be in Florida. Easiest solution is to move to a state that is more than 10' above sea level.

#

 

[fel3]

This appears to be in Florida. Easiest solution is to move to a state that is more than 10' above sea level.

#

I'm currently helping a project team (as technical advisor and QA/QC reviewer) who are looking at alternatives for improving an existing underground storm drainage collection system that serves a portion of an international airport that adjoins a bay off of the Pacific Ocean. The ground surface in the area in question is about 12 ft above MSL, high-high tide is about 7.5 ft above MSL, and the soffit of the outlet pipe is about 7.0 ft above MSL. So, even with a TideFlex valve inside the outlet pipe, it is sometimes impossible to dewater the downstream parts of the system as desired by the client. In addition, periodic exposure to brackish water has degraded the RCP outlet pipe, a couple of manholes, and an upstream storm filter unit housed in a concrete vault. I told the project team that I saw two solutions to the brackish water problem: [1] install a small pumping station to dewater the pipe and structures behind the TideFlex valve, or [2] move the airport. I also told them that "the pumping station would be a little cheaper."

 

[Deenie]

Unfortunately, your attachment doesn't clearly show the pond. Based off the information, I was able to look at it through Google Maps & Street View. It looks like there is a very small triangular pond in the corner of the property behind the dentist office. Could this pond be extended to run E-W along the northern property line. This would get you a bigger pond, but I doubt that anything could be adequately sized for dealing with hurricanes. It appears that there is a culvert only because there is a lighting for the parking lot. Removing the culvert and replacing with a channel may allow for faster flow of water from the south to your detention pond.

I am sorry the picture was not true to spec. Thank you so much for responding. I am assuming we need to dredge a channel on the east side from south to north. The larger retaining pond in the back of the property which belongs to the building next to us, needs to be dredged as well. The water is not going away we need to have it flow better.
I wonder if it is logical to have the waterways dredged at the beginning of every hurrican season. Any suggestions on erosion control behind the buildings?