1. Living Shorelines:
The origins of a practice, the sudden rise of interest within the stormwater community,
and the debate
Jana Davis
Chesapeake Bay Trust

2. Definition of Living Shorelines
"Living shorelines" are defined as shoreline stabilization techniques that use as many natural habitat elements as possible to protect shorelines from erosion while also providing critical habitat for Bay wildlife.
Concept of “as many as possible” and “site conditions” 2

3. The “Problem:” Eroding Shorelines
33% of all Chesapeake Bay shorelines are actively eroding.
This all started because… from a landowner’s perspective – erosion a problem.

4. The “Problem:” Eroding Shorelines
Erosion is a natural process
7,000 years ago
present
10,000 years from now
We have to keep perspective
Maps courtesy of UDel

5. The “Problem:” Eroding Shorelines
Erosion is a natural process.
Human processes play a role.
Sea Level Rise: > 1 foot (40 cm) last century
So maybe it is partly legitimate to call it a problem

6. Hardening of Shorelines
We’re hardening our shorelines to protect against erosion
28-32% Maryland is armored
11-19% Virginia is armored

7. Hardening of Shorelines
But armor doesn’t always work,
and people starting thinking it might not be so good for critters

8. History of “Living Shorelines”
● 1970s Environmental Concern begins using purely non-structural
approaches. Failures abound
● 1980s “Hybrid” projects introduced
● 1980s “Living shorelines” term coined in Maryland
● 1990s-2000s Implementation of projects in MD, VA, NC takes off
So the technique of “lving shorelines” was born. 8

9. Types of Living Shoreline Projects/Designs
Living Shorelines
Structural practices
low structure
high structure
practices without a natural habitat component:
Bulkheads/Seawalls
Revetments
Breakwaters
Groins/jetties
Non-structural living shorelines:
natural habitat elements only: vegetation, oyster reef, coarse woody debris, sand.
Hybrid living shorelines:
include natural habitat elements, as well as some hard structures such as stone sills or breakwaters
Non-structural living shoreline
Structural erosion control practice
Medium-structure hybrid living shoreline
Low-structure hybrid living shoreline

10. Non-Structural
BEFORE
Hidden Pond,
Crownsville, MD
AFTER

11. Low Structural St. Johns College, Annapolis, MD BEFORE AFTER
Just to give you a sense of the change…

12. Hybrid Living Shorelines
Continuous Sill With Windows
Segmented Sill Design
window/tidal gate

13. Hybrid Living Shorelines
BEFORE
AFTER
Chesapeake Maritime Museum,
Miles River
Can also be built in front of existing armor

14. High Energy/High Structure
Chesapeake Bay Ecology Center, Grasonville, MD
Asbury Retirement Home, Calvert County
Breakwaters
Different types 14

15. History of “Living Shorelines”
● 1970s Environmental Concern begins using purely non-structural
approaches. Failures abound
● 1980s “Hybrid” projects introduced
● 1980s “Living shorelines” term coined in Maryland
● 1990s-2000s Implementation expands
● North Carolina passes Living Shoreline Law (HB 1028)
● early 2000s Delaware puts “no bulkhead” policy in place
● Florida state gov’t begins Living Shoreline Initiative
● Maryland passes Living Shoreline Protection Act
So the technique of “lving shorelines” was born. 15

16. History of “Living Shorelines”
● 1970s Environmental Concern begins using purely non-structural
approaches. Failures abound
● 1980s “Hybrid” projects introduced
● 1980s “Living shorelines” term coined in Maryland
● 1990s-2000s Implementation expands
● North Carolina passes Living Shoreline Law (HB 1028)
● early 2000s Delaware puts “no bulkhead” policy in place
● Florida state gov’t begins Living Shoreline Initiative
● Maryland passes Living Shoreline Protection Act
Connection to other issues: Climate Change and Bay Pollution
● MD Climate Action Plan - LS as climate change defense
● 2015 Bay Program gives LS N, P, and S credit –
Expert Panel on Shoreline Management Practices
Living shorelines suddenly become the solution to everything – climate change and SLR, bay pollution – where maybe they were never intended to solve the problem 16

17. Solutions for multiple ills: Deserved, or overstated?
The Debate:
Living Shorelines as
Solutions for multiple ills:
Deserved, or overstated?

18. Sources of Sediment “Pollution?” in the Chesapeake
Watershed – Ag and SW
Oceanic Input
Shoreline
5.2 million tons/year
Oceanic
Watershed
So we’re not going to talk about climate change and SLR – that is another story for another day – but let’s switch gears and go back to our earlier discussion about sources of
Shoreline

19. Sources of Sediment “Pollution?” in the Chesapeake
Watershed – Ag and SW
Oceanic Input
Shoreline 19

20. Sources of Sediment “Pollution?” in the Chesapeake
Watershed– Ag and SW
Oceanic Input
Shoreline
We don’t know the percentage of erosion from boat wakes

21. Is sediment all bad?
Coarse grain sediments important for habitat – SAV, wetlands, coves, helps keep up with SLR

22. Expert Panel “Protocols” to give reduction credits for shoreline erosion control practices
Tidal Marsh Denitrification
85 lbs/acre of revegetation
Sediment Trapping through Accretion
5.289 lbs P/acre, 6,959 lbs sediment/acre of revegetation
Marsh Redfield Ratio – Standing Crop of Vegetation
6.83 lbs N/acre of revegation, 0.3 lbs/acre – 1 time credit (not annual)
Prevented Sediment
In MD – assumes 2.43 kg/m/d reduction x (because 44% is coarse)
In VA – assumes 1.01 kg/m/d x (because 66% is coarse)
As of July 2015, WTWG recommended to eliminate the nutrient credit for prevented sediment pending further study.
Concerns that the cumulative BMP loading reductions could possibly exceed available simulated loadings.
Denitfrification and sediment trapping- avg from studies

23. Baltimore County Essex Skypark Example
2,610 linear feet
Before: erosion rate ft/yr
bank height 4-7 ft
After: 1.8 acres vegetation
Total pollutant load:
165.3 lb TN first year, 153 lb/yr future
10.6 lb TP first year, 9.52 lb/yr future
462,596 lb TSS/yr

25. Folks start asking: Are we sure these things “work?”

26. Nekton: several species increased at LS; none decreased
Blue Crab
After-Before (change in density; #/sq m)
Species density
Striped Bass
We measured a total of 18 species. Of 6 species abundant enough both in time and at the various sites for analysis…