Phase II. Task 3 ReportProject: Development of a Hydrodynamic/Salinity Model for Naples Bay and Rookery Bay.

Phase II

Revision date: September 8, 2015

Submitted by Y. Peter Sheng (pete@coastal.ufl.edu), Vladimir Paramygin (pva@coastal.ufl.edu)

Summary of Simulation Scenarios

There are three types of scenarios that will be studied for the Task 4 of this contract. They include:

a) Natural (historical) system flow conditions. These flow conditions are established based on the historical system model by Interflow Engineering, LLC 1. This model was designed to estimate the changes in volumes and timing of freshwater inflows to Rookery Bay that have occurred over the past several decades due to anthropogenic impacts. The historical model provides results for the analysis of the watershed in a pre-development or historical condition against conditions as they are today (existing conditions). Important aspects of the model setup, including saturated zone layering and parameters, rainfall and potential evapotranspiration, soils and land-use dependent parameters, etc. were held constant between the existing and historical conditions models. The design of model inputs and outputs ensured that the differences between the two models are solely attributable to anthropogenic changes in the watershed. For historical conditions, all man-made features from ditches/canals and control structures, to detention/retention ponds and mining operations have been removed from the network. As a result, the model simulates the flow of water in a natural manner to an outfall based upon the topography and other physical properties within the watershed. Details of the model development and differences between the existing and historical flow conditions can be found in the appropriate report (1).

b) Reduced flow at Henderson Creek station (HC1, Figure 1). These scenarios are designed to determine the effect of Rookery Bay freshwater inflow on both Rookery Bay and Naples Bay and how flow reduction affects the salinity in either bay overall and seasonally.

c) Reduced flow at Golden Gate station (GG1, Figure 1). These scenarios are designed to determine the effect of Naples Bay inflow on both Rookery Bay and Naples Bay and how flow reduction affects the salinity in either bay overall and seasonally.

The exact scenarios are listed in Table 1. We will attempt to identify whether changes in fresh water flow cause shift in biological salinity zones as defined by Bulger et al. 1993 (2) overall and during dry and wet seasons at different important locations that were provided by the district and listed in Table 2.

Table 1. List of simulation scenariosScenario Name Comments

1 Natural flow conditions Based on historical system model by Interflow Engineering, LLC2 HC1 -5% 5% flow reduction at HC1 station3 HC1 -10% 10% flow reduction at HC1 station4 HC1 -20% 20% flow reduction at HC1 station5 HC1 -30% 30% flow reduction at HC1 station

1 http://cerpmap1.cerpzone.org/arcgisapps/CERPMMS/CerpReport/ProjectReport.aspx?projectID=907

6 GG1 -5% 5% flow reduction at GG1 station7 GG1 -10% 10% flow reduction at GG1 station8 GG1 -20% 20% flow reduction at GG1 station9 GG1 -30% 30% flow reduction at GG1 station

Figure 1. Map of the domain, CH3D model grid and data stations

Table 2. List of output stationsSite Latitude Longitude Location DescriptionGORDPK 26.14869 -81.78622 Naples Bay, south of WWTP outfall by Pulling ParkGORDEXT 26.15759 -81.78414 Gordon River just past City LimitsROCKCR 26.14201 -81.7834 Rock Creek just past City LimitsPORTROYAL 26.10758 -81.79569 Up into canal of Port RoyalNBAYNL 26.13472 -81.79197 Naples LandingMIDBAY 26.12613 -81.78926 Naples BayNBAYHC 26.12083 -81.78506 Haldeman CreekNBAYWS 26.11317 -81.78604 Naples Bay near Marker 24, Windstar dock/shoalNBAYBV 26.10136 -81.78519 Naples Bay, Bayview ParkGPASS6 26.093 -81.79858 Naples Bay, just inside Gordon's Pass at Marker 6LH 26.0257 -81.7332 Lower Henderson CreekCNISLE 25.974 -81.74583 Coconut IslandJHNSBAY 25.996 -81.739 Johnson BayHALLISLE 26.04242 -81.774638 Halloway IslandHALLBAY 26.01924 -81.738712 Hall BayROOKBAY 26.028975 -81.745651 Rookery Bay

Figure 2. Model output locations

References:(1) Interflow LLC, 2014. Task 2.7 Hydrodynamic Modeling Report, Henderson Creek Watershed Engineering Research Project, MIKE SHE/MIKE-11 model development, June 27, 2014.

(2) Arthur J. Bulger, Bruce P. Hayden, Mark E. Monaco, David M. Nelson and M. Geraldine McCormick-Ray. Biologically-Based Estuarine Salinity Zones Derived from a Multivariate Analysis. Estuaries, Vol. 16, No. 2 (Jun., 1993), pp. 311-322, http://www.jstor.org/stable/1352504.