Weeks Bay

Draft Watershed Management Plan

Public Workshop August 16, 2017

Baldwin County Central Annex

Weeks Bay Watershed

Schedule

Jan 2016 Initiation

Feb-Dec 2016 Public Involvement, Data Collection and Analysis

Apr 2017 Implementation Measures

Jul 2017 Draft WMP Report

Sep 2017 Final WMP Report

Oct 2017-??? Implementation

Watershed Management Plan Team

Mobile Bay NEP

Baldwin County Soil and Water Conservation District

Thompson Engineering

Vittor and Associates

Ecology and Environment

Bob Higgins

Latif Kalin

Hand-Arendall, Neil Johnston

Public Involvement

Bob Higgins, Team Lead

Stakeholders Working Group

Website/Newsletters

Public Meeting – Mar 2016

Focus Meetings

Draft Report Public Review

Public Meeting – Aug 2017

Final Report

Literature/Data Collection “Thank You” to Weeks Bay Reserve Outstanding Available Literature GIS Data Layer Examples

– Population/Land Use/Impervious Cover – Political Jurisdictions – Sediment/Water Quality – Septic Tanks and Sewer Systems – Erosion Sites/Dirt Pits/Unpaved Roads – Livestock/Turf Farm Survey – Wetlands/Streams/Riparian Buffers – Shoreline Assessment/Sea Level Rise – Public/Protected Lands and Access – Stormwater Ponds – Monitoring Stations

Watershed Characterization/Issues

Complex Municipality/County Environment

Water Quality – Pathogens

– Sediment

– Nutrients

Flooding

Wetlands/Riparian Buffers

Shoreline Assessment/SLR

Zoning Map

Regulatory Matrix

ADEM Baldwin County Fairhope Daphne Spanish Fort Loxley Robertsdale Silverhill Magnolia Springs Summerdale Foley

Construction Phase BMPs Requirements Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

Design Standards AL Handbook AL Handbook AL Handbook AL Handbook AL Handbook ALDOT

Specifications Loxley Regulations USDA

Field Manual USDA Field Manual USDA Field Manual AL Handbook EPA AL Handbook

Design Storm 2yr-24hr Not Specified Not Specified 2yr-24hr 10 yr 10 yr 25 yr Not Specified 25yr -24hr Not Specified Not Specified

Site Size >1 ac. Any All >1,000 ft2 >1 ac. 1, 5,& 10 ac >1 ac. >1 ac Not Specified >1 ac 500 feet²

Stabilization Time Immediate 10 or 13 days 10 days 13 days 30 days Not Specified "minimized" 30 days 13 days Not Specified 14 days

Site Inspections I/month + 3/4"

rain Yes City-Random;

Contractor-Daily Yes Yes No No No No No City-Random /

Contractor-"regular"

BMP Repair/Maint. Time 5 days Not Specified 2 Days 2 Days Not Specified Not Specified No Not Specified Not Specified Not Specified 2 Days

Non-compliance Reporting Yes No No No No No No No No No No

Buffer Requirement Yes- 25' No 20' / 30' No Yes, Unspecified Width No Yes-Unspecified Width Yes-Unspecified Width Yes - Varies No 30'-Wetland / 50'-

Waterway

Post Construction SW Mngt Requirements No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

Stormwater Quality No No

Treat 1.8", 85% Capture,

80% TSS Removal Yes No No No No Yes No Yes- Treat First Flush (1")

Stormwater Quantity No Yes - Considers Timing Yes - Considers

Timing Yes Yes Yes Yes Yes Yes Yes Yes

Design Storm N/A 2 - 100 yr 2 - 100 yr 2 - 100 yr 2 - 100 yr 20 yr 25 yr - 24hr 10 yr 2 - 100 yr - 24hr 100 yr 2 - 100 yr

Site Size N/A Any All Subdivisions Any

Non-SF Developments: > 1 ac. SF Developments: 5 ac.

Any Subdivision. 1, 5 & 10 ac All Subdivision,

Commercial, Industrial Commercial, Industrial, Residential Subdivisions Not Specified

> Triplex SF, Commercial,

Industrial 500 feet²

Routine Inspection N/A No 1/ 3 yr 1 / 5 yr No No No No 1 per 3 yr / 1 per 2 yr No Annual

Maintenance N/A Developer Owner Developer/Landow

ner Developer Trustee Developer/Owner Assoc. Developer/Landowner Developer/Owner Developer/Landowner Developer/Landowner Developer/Owner Owner

Reporting N/A No Yes Yes No N/A No No No No No

Calculation Method N/A SCS Rational <100 ac,

SCS >100 ac Rational or Modified Rational

Method

<200 ac. Rational Method >200 ac. Regression Equations

or SCS Loxley Regulations USDA

Field Manual Rational </= 200 ac SCS Not Specified Not Specified Various

Coastal Area Resource Protection Yes No Yes Yes Yes No No No Yes No Yes

Wetland/Stream Buffer 25 ft. N/A

Wetland-20'/30' Streams 50'-100' (by watershed) Stream 50' Wetland 30' 15'-50' N/A No N/A 30 feet N/A

30'-Wetland / 50'-Waterway

Permit Requirement Yes N/A Yes USACOE Yes N/A No N/A Yes N/A USACE/ADEM

Low Impact Development No No Yes Yes Yes No No No Yes No No

Development Size N/A N/A Not Specified No N/A No No N/A Not Specified N/A N/A

Impervious Cover No No Optional No N/A No No N/A Optional N/A N/A

On-site Retention No No Optional No N/A No No N/A Optional N/A N/A

LID Standards No No Not Specified Yes N/A No No N/A 85% Treatment - 80%

TSS Removal N/A N/A

Impediments to LID N/A N/A No No N/A No No N/A No N/A N/A

Shoreline Stabilization Yes No No No No No No No Yes No Yes

Piers and Bulkheads Yes N/A N/A USACE, ADCNR ADEM Verification N/A No No N/A Yes N/A Yes

Living Shorlines No N/A N/A USACE, ADCNR ADEM Verification N/A No No N/A Not Specified N/A No

MS4 Permit Coverage N/A Yes Yes Yes Yes No No No No No No

* Alabama Handbook for Erosion Control, Sediment Control and Stormwater Management on Construction Sites and Urban Areas, September 2014

Watershed Management Analytical Tools

Soil and Water Assessment Tool

Baldwin County Flood Model

Ecological Assessment

Sea Level Rise Analysis (SLAMM)

GIS Analysis for Various Datasets

Baldwin County Population Growth

Watershed Population

2010 Census 2040 Projection

Agriculture Forest Urban Wetlands Acreage

Upper Fish River 39% 35% 15% 11% 42,000

Middle Fish River 58% 20% 10% 12% 27,000

Lower Fish River 43% 16% 15% 26% 34,500

Magnolia River 64% 9% 13% 14% 26,000

Weeks Bay Subwatersheds Land Use

(2011)

Land Use

2040 Medium

2011 2040 High

Impervious Cover

2001 2011

Septic Tanks (2002-2016)

Livestock & Turf Farms

Unpaved Roads

Stormwater Ponds

• Watershed Model

• Process-based

• Distributed

• Continuous Simulation

• Deterministic

• Loading Model

Soil Water Assessment Tool (SWAT)

197 Subw. 858 HRUs

40 Subw. 264 HRUs

Daily Flow Duration Curve - FDC (m3/s)

SWAT Model Sediment

SWAT Model Nitrogen

SWAT Model Phosphorus

Watershed Wetlands

Wetlands Condition

Riparian Buffer Condition

Historic Shoreline Changes

Historic Shoreline Changes

Historic Shoreline Changes

Historic Shoreline Changes

Sea Level Rise (SLR) Records

Mean Relative Sea Level has risen 6.5 inches in the Mobile Bay Area since 1966

Sea Level Rise (SLR) Projections in Mobile Bay Area (by National Oceanic &

Atmospheric Administration (NOAA) and U.S. Army Corps of Engineers (USACE)

1.1 ft

4.4 ft

7.1 ft

Potential Effects of SLR Inundation Models

Predicted inundation along a portion of Fish River (as an example) under 3 SLR scenarios using NOAA’s Online SLR Viewer

Keeney Dr.

Juniper Ln.

Potential Effects of SLR Habitat Change Models

Sea Levels Affecting Marshes Model (SLAMM)

Predicted habitat conversion (showing uphill migration of wetlands) at mouth of Magnolia River (as an example) Under 3 SLR Scenarios

Protected Lands

Monitoring Sites

Financing Options Public (Local, County, State,

Federal)

Private

Public-Private Partnerships

Examples of Funding Sources – Section 319 Grants

– NRCS Programs, e.g. EQIP, CSP, EWP

– RESTORE Act

– NFWF Gulf Envir. Benefits Fund

– Gulf of Mexico Energy Security Act

– AL Coastal Area Management Program

Short-Term Measures Establish WMP Implementation

Team

Establish Watershed Coordinator at BCSWCD

Municipality/County Coordination Mechanism

Establish a County GIS Layer for Municipality Coordination

Initiate Monitoring Program

Continue Public Outreach and Education

Long-Term Measures Promote Low Impact Development Measures Encourage County to Run Flood Model

Periodically Increase Agricultural BMPs, NRCS Conservation

Programs Stormwater Pond Assessment and Maintenance Implement Sediment Reduction Projects Pave Priority Dirt Roads Implement Nutrient Reduction Projects Address Pathogen Sources Identification and

Reduction Restoration Projects for Streams, Wetlands, and

Riparian Buffers Strategic Land Acquisition/Protection Manage Invasive Species Long-term planning to recognize potential Sea

Level Rise Construct Living Shoreline Projects

Thank You!!

Now We’ll Transition to the Draft

Recommendations Prioritization

Exercise