20230797 Ver 1_More Info Received_20231212

From:
Behm, Pamela
To:
Snider, Hollev
Subject:
west carteret boat launch
Date:
Tuesday, December 12, 2023 1:06:10 PM
Hi Holley,
We've written up the requirements for the boat launch for Richard to send, but please review and
add anything else that might be needed:
Modeling requirements
After review of the submitted materials and consultation with upper management, a nonproprietary
model is needed in order to evaluate both flushing and dissolved oxygen for the proposed boat
launch. There are three key steps from the Marina Planning guidance document that are impacting
Modeling Branch review because these steps were not followed in the initial submittal:
• From page 15 — "All models used must be in open format (no proprietary models) and all
data used to populate models must be included."
• From page 16 — "Pre -project sampling locations and parameters must be pre -approved
by DWQ...,,
• From page 17 — "Consultations with DWQ at an early stage in the project proposal can
greatly enhance the prospect of achieving a successful marina development. Once the
various site assessments and technical analyses have been completed, it will be possible
to prepare a preliminary development proposal. It is advisable the developer "Scope"
the process with DWQ before commencing work on preparing project proposals.
Scoping meetings are an excellent avenue to discuss project feasibility with various
permitting authorities and give the developer an early indication of the views of the
permitting authorities."
The MIKE21 model described in the submitted materials is not open format and provides no
information on dissolved oxygen. Collected data were not submitted either (first bullet above).
The EFDC hydrodynamic and water quality model has been the most commonly used model recently
for other marina projects. Other potential models include WASP (which will still need EFDC for the
hydrodynamics) and CE-Qual-W2.
Comments related to the submitted materials:
1. As currently written in the provided memo, the flushing capability was assessed using MIKE21
by releasing dye (conservative tracer) at one point of the basin for 20 min at the
concentration of 100. The time series of dye concentration was then used to assess flushing.
In fact, the time series of dye concentration at the releasing point is heavily influenced by
how much (or how long) dye was released. It's a function of both mixing (with neighboring
cells) and tidal flushing. In order to look at the capability of tidal flushing in the basin, either
dye needs to be released into the entire basin (e.g. initial condition set to 100) or, for current
model scenario, the time series of total volume of dye within the entire basin needed to be

assessed.
2. Model calibration was mentioned in the document, but calibration results were not shown.
3. Boundary condition is critical to the well representation of tidal flushing capability
represented in this model, a detailed description or a good reference to the "Flather
condition" is needed to clarify the boundary condition used. In addition, "average tide" and 5
tidal constituents are both mentioned in the memo, but more detailed descriptions should
have been included.
Pam Behm
Branch Chief
Modeling and Assessment Branch, Planning Section, Division of Water Resources
Department of Environmental Quality
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