Stream Smart Road Crossings
& Maine Barrier Surveys
Alex Abbott
Welcome!
GIS Analyst & Restoration Specialist
Under Contract to:
Gulf of Maine Coastal Program
U.S. Fish and Wildlife Service
Welcome! Thanks for taking the time to join us today.
1
Stream Smart Crossings…
Maintain fish and
wildlife habitat
while protecting roads
and public safety.
Stream-smart crossings maintain fish and wildlife habitat
while protecting roads and public safety.
They also help us be prepared for the large and frequent
storm events that have been washing out roads around
the state and the northeast in recent years.
Ask, “What values are most important to you?”
Free-flowing streams are valuable
Because they support our world class fisheries.
Fishing is the most popular outdoor sport in Maine,
with over 260,000 recreational anglers.
This generates significant economic benefits:
$100 million in wages and salaries
$200 million in retail sales
$20 million in tax revenues
Stream fishing is an important mainstay in many
rural economies throughout the state.
Over 50 native fish benefit from the increased stream access
and improved habitat that stream-smart crossings provide.
Healthy streams also greatly reduce flood damage and
associated costs not reflected in the benefits just mentioned.
3
Brook
Trout
Though we’ve got more intact populations than elsewhere,
our habitat is impaired, too.
Again, green on the map represents areas with intact
brook trout populations, spread over a good portion of the state.
Red represents impaired brook trout habitat.
One of the contributing factors in degrading these red areas
is the lack of stream-smart crossings.
Fish need to move
Cold Water Refuge Deep Water Refuge
Spawning Habitat
Foraging Areas
Nursery Habitat
Seasonal Habitats
So why do fish need free-flowing streams?
Because they need to move.
So connected streams are critical!
Fish need to move because they cannot find everything they
need to survive and reproduce in one location.
They need large connected areas of HABITAT, or “living space”.
This habitat needs to have essential elements for fish to thrive,
and fish need to have access to enough of it
and if it is blocked or fragmented, or otherwise limited, fish suffer.
One analogy is to think about a small fish tank where fish can only
get so big because of the space available to them.
This is similar to fragmented stream habitat; when fish are not
able to reach essential habitat fish health can suffer,
and can even changes them genetically (i.e., selecting for small fish).
Movement is important for:
Daily feeding, shelter and resting
Seasonal and other changes in habitat conditions,
like during low flows in summer, and with ice in winter
Reproduction – finding suitable spawning areas
Dispersal to find suitable nursery habitat
Overall - access to a variety of habitats:
spawning, nursery, foraging, deep water, cold water refuge
5
As an example, Atlantic salmon parr and young brook trout
are often found miles from where they were born:
3-5 miles for salmon parr; adult trout will often move 12 miles if able.
5
It’s not just fish
Photo: NH Public TV
But free-flowing streams don’t just benefit fish.
They benefit everything that supports the fish,
from insects to microorganisms.
They benefit everything that relies on streams,
whether they live there or just stop by for a meal.
Freshwater mussels filter water and provide food for other things,
including species that live on land or come to streams occasionally.
Many species thought of as terrestrial, or land-dwelling use stream
channels, riparian areas or floodplains.
Stream channels are important corridors for animals such as
mink and otter, salamanders and turtles.
Without stream-smart crossings, such animals are often forced to travel
by crossing roads, with unfortunate consequences.
And…Altered Stream Processes
It’s also what the stream does
Regulates the flow of water
What else does a free flowing stream do
aside from offering habitat for fish and wildlife?
It regulates the timing and duration of stream flow
in a way that supports fish and wildlife,
and also helps people because it stores flood waters.
Altered Stream Processes
Moves organisms and material
Free-flowing streams transport material that
creates and maintains habitat for fish and wildlife,
including a continual supply of nutrients and insects,
food for many of them, and woody debris, and sediment.
This material creates places for wildlife to rest, feed, and spawn,
and supports the health of the stream.
Altered Stream Processes
Maintains water temperature
Free flowing streams allow for natural temperature variations
that fish and wildlife are adapted to deal with.
Small streams are essential.
They make up a large percentage of stream miles
Cumulatively providing more habitat than large rivers
Provide important spawning and nursery habitat for fish.
Smaller streams have higher densities of juvenile Atlantic Salmon and Brook Trout
Support species not found in larger streams and rivers
10
OK, so free-flowing streams are
valuable.
What’s the problem?
Barriers!
Road crossing culverts are the major barrier fragmenting stream habitat.
With a design life of 30+ years, culverts can be fairly long-term barriers.
But they don’t have to be.
While culverts have traditionally been intended only to pass water,
without causing problems for the road,
It’s only recently that we’ve begun to understand how they need
to be designed in order to work with the stream.
Now stream-smart designs can meet our transportation needs w
hile allowing the stream to flow freely.
11
HOW do culverts block
fish passage?
A) Flow too fast
– Undersized or
Too Steep
A
B
C
B) Flow too shallow
– Set too high
C) Physical barrier
– Outlet free fall
– Inlet Blocked
– Thermal Barrier
Essentially there are three ways culverts block fish passage.
Often there is a combination of passage problems at a site.
12
Flow too fast
When a culvert is too small for a stream, the water flows faster.
The culvert acts like a funnel, with the upstream water held back
as in the wide part of a funnel, and the flow through the culvert
is much faster like the liquid coming out of a funnel.
Even if a fish was able to get into a culvert like this, there is a
good
chance that it would be too exhausted to travel the whole length
of the culvert without any chances to rest.
And to top it off, in this culvert, the fish would also have to be
able to jump up into it.
13
Flow too shallow
At first glance it looks like this culvert is way over-sized,
but only because this view is of low summer flows.
During higher flows, for example in the spring and fall,
this culvert may not be a fish barrier.
However, during the summer months in low flow conditions
when fish are seeking cold water refuge upstream or need
to move for other reasons, this culvert is a fish barrier.
14
Physical barrier: Outlet free fall
Perched culverts are another example of how an
improperly installed culvert reduces stream passage.
This picture represents a severe case, but perched
culverts are extremely common.
15
Physical barrier: Inlet blocked
Culvert
Another extremely common result of undersized culverts
is debris blocking their inlets.
The smaller the pipe, the more likely to clog.
Frequent maintenance is needed to avoid
road washouts and culvert failures.
Tidal restrictions: Shrinking wetlands
In addition to everything we just talked about,
barriers on tidal streams can have dramatic habitat impacts
And the impacts are…
Reduced wetland acreage, smaller salt marshes
Whether they are perched or simply undersized,
road crossings on tidal streams can often restrict
the amount of water reaching upstream wetlands
during the flood tide, which means fewer acres are
wet during the average high tide and the marsh shrinks.
On salt marshes, a lack of tidal flushing creates conditions
favored by invasive species like the common reed,
which can take over and limit habitat for the salt marsh fish
and wildlife that used to live there.
Since 2007, many partners in Maine have conducted surveys to identify
and rate crossings across the state, providing us with lots of data
to set priorities for restoration – over 20,000 records.
Maine has assessed more of its stream crossings proportionally than
any other state in the nation, and while this data is not complete,
it provides very valuable information.
Culverts are often barriers
All
Crossings:
Culverts
Only:
n = 16,525
n = 12,270
Maine field surveys over the past few years show that most road
crossings with culverts act like thousands of dams across the state.
40% are barriers and another 40-50% may be barriers
at certain times of the year or for some species and ages groups of fish,
and are certainly barriers to the healthy free flow of their streams.
The problem is widespread
Within a part of the watersheds of southern Maine shown here
are at least 700 barriers due to problem culverts.
Barriers prevent or limit upstream access, so an average of 25-40% of
stream miles
are blocked to fish and other organisms.
20
Maine Stream Habitat Viewer
I’d like to run through just a few features of the Viewer so you get a sense of how it’s
information can be used…
Here I’ve selected my geographic area of interest using the Search tool and we’re now
looking at the town of Cushing on Maine’s Mid-Coast.
21
Maine Stream Habitat Viewer
I’d like to run through just a few features of the Viewer so you get a sense of how it’s
information can be used…
Here I’ve selected my geographic area of interest using the Search tool and we’re now
looking at the town of Cushing on Maine’s Mid-Coast.
22
Maine Stream Habitat Viewer
I’d like to run through just a few features of the Viewer so you get a sense of how it’s
information can be used…
Here I’m using the Search tool to find the town of Cushing.
23
Maine Stream Habitat Viewer
The Viewer zooms me to the town of Cushing on Maine’s Mid-Coast.
24
Maine Stream Habitat Viewer
I also decided that the basemap I was using was too faint, so I switched to another (USA
Topo).
Next I’ve turned on the layer for Documented alewife habitat, shown as green ponds here…
25
Maine Stream Habitat Viewer
And also Rainbow smelt habitat (purple) so you see we have a potential barrier located in
documented smelt habitat and below a small alewife pond.
26
Maine Stream Habitat Viewer
I want to learn more about this road crossing, so I simply click on the crossing …
27
Maine Stream Habitat Viewer
And find that it’s a single culvert surveyed in July 2010…I check the photos to see what the
site looks like from various angles, and
I find that the span of the culvert is about 1/3 of the stream width, so the stream is severely
constricted – which could be a problem for upstream alewife and especially smelt passage
due to high velocities.
28
What failure looks like
Extended Video Of Freeport Road Collapse:
http://www.youtube.com/watch?v=p_uqPR4Ir5o
Has anyone experienced anything like this?
What failure looks like
Photo: Scott Craig, USFWS
This catastrophic road washout in Acadia National Park
was the result of an undersized culvert overwhelmed by a storm.
The culvert was blocked with debris so the stream made a
new channel down the road, but the culvert did not blow out.
30
Road washouts: Bad for budgets…
Tons of
Material
Item
400 Imported gravel and base material ($21 / ton)
2 employees/trucks (80/hrs @ $45)
50
1 employee/backhoe (60 hrs @ $75 / hr)
Road Work- Grader/excavator (40 hrs @ $100 /hr)
450
Cost
$8,400
$3,600
$4,500
$4,000
$20,500
Photo: Scott Craig, USFWS
The cost of failure can be high, in this case, over $20,000 dollars
was spent to fix the road, but the undersized culvert is still there.
How many more times will it fail, necessitating more road repair?
A stream-smart open-bottom arch that exceeds the stream channel
could have been done for between $26-30 K.
31
…also bad for habitat
When culvert crossings fail either entirely or a little bit over time,
stream habitat is impacted by road fill washed downstream.
You don’t need a complete failure to affect stream process,
even losing a load of gravel each season will have an impact.
Fine sediments can suffocate fish eggs.
Spaces where fish can hide between rocks can be filled with sediments.
Spawning habitat for salmon can be covered, as can
invertebrate habitat limiting available food to fish,
mammals, reptiles, and amphibians.
32
Big storms will become
increasingly likely
43%
Extreme storms
We are facing an increased likelihood of large,
more frequent storm events with more rainfall.
Based on trends in the frequency of large snow
and rain events over the past half century ,
Maine faces a predicted 43% increase
in extreme storm events.
43% is specific to Maine and comes from
"When it Rains, It Pours: Global Warming and the Rising Frequency of Extreme
Precipitation in the United States," Appendix B – page 36
•
They measured trends in the frequency of large rain and snow events across
from 1948 to 2006.
•
Data from 3,000 weather stations
•
Methodology originally developed by scientists at the National Climatic Data
Center and the Illinois State Water Survey,
•
Identified storms with the greatest 24-hour precipitation totals at each weather
station, and analyzes when those storms occurred.
Vermont – Hurricane Irene 2011
Vermont was devastated in August of 2011
as Hurricane Irene tracked inland.
Over 1,000 culverts in the state were damaged
or destroyed, and even many bridges, too.
Now, this was a Tropical Strom, rare and not necessarily
representative of the many more, smaller, but
more frequent and intense storms we can expect.
In the case of major storms like Irene,
we find that undersized crossings fail while
Stream Smart crossings tend to survive.
34
Machias River, Maine – December 2010
On December 13-14, 2010 Downeast Maine received a
50 to 75 year storm event, 20 times a normal stream flow.
The combination of frozen ground, 12 inches of snow, and
heavy rain created this significant flow event.
The photo is of the Machias River just below route 9.
These are the kinds of storms we are expected to have more frequently.
35
The Aftermath
In the aftermath of the storm, this 12 foot diameter culvert
was ripped out, crushed and thrown downstream.
36
Sea level rise will magnify
impact on tidal streams
Eastport, ME
~ 6.1” rise since 1929
Portland, ME
~ 6.8” rise since 1912
Predictions of rises
up to 6.5’ by 2100
In addition to increases in the frequency and intensity
of large rain storms, we are already experiencing
Sea Level Rise.
It’s a process that’s been underway
for thousands of years.
Based on the observed rate of local sea level rise over
many decades, Maine anticipates a 2 foot increase
by the end of the century, though it could be much larger.
This means we will see
more overtopping of tidal culverts,
and a potentially catastrophic failures
when coupled with extreme storms.
37
Luckily, there are solutions.
Stream Smart crossings
maintain fish and wildlife habitat
while protecting roads and public safety.
They also provide a buffer from more frequent,
severe storms and sea level rise.
38
What makes a solution Stream Smart?
Pre-restoration
39
Photos by K. Mueller
What makes a solution stream-smart?
Supports your intended use
Construction and maintenance costs fit your
budget and planning horizon
Passes design flood flows
Limits construction disturbance
Minimizes long-term maintenance
Enables passage of fish and other organisms when they want
Passes sediment and woody debris
Maintains natural channel flow characteristics
Complies with State and Federal permits
Old culvert in top left in August, to the right is
the new crossing functioning in September.
39
39
The same stream-smart bottomless arch just shown handling
the water from the December 2010 downeast storm just fine.
40
A stream-smart bridge design with concrete
waste block abutments handling the water
from that December 2010 storm just fine.
41
A stream-smart bridge design with concrete
waste block abutments handling the water
from that December 2010 storm just fine.
42
A Wise Investment
Photo: Dan McKinley, GMNF
2010
After Tropical Storm Irene
September 2011
The Vermont experience with Irene is telling:
The failure of one 24-inch culvert alone cost the town
of Royalton, VT $250,000 to fix.
On the other hand, the Green Mountain National Forest
had resized culverts before Irene, and they didn’t lose a single one.
This photo shows one of the resized GMNF culverts:
the only damage from Irene were a few moved boulders
near the outlet and along the sides.
The structure and road were undamaged.
If more frequent big storms is the “new normal” for our
region’s climate, stream-smart crossings represent a wise
investment and protection against natural and economic catastrophe.
Stream Smart Crossings…
Maintain fish and
wildlife habitat while
protecting roads and
public safety.
Allow the stream to act
like a stream, passing fish
and wildlife as well as the
higher flows that come
with larger, more frequent
storms.
Where do you have stream crossing issues?
Chronic maintenance issues?
Trouble during high flows?
Places where you end up sending a crew year after year?
Many Thanks to the members of Maine’s
Stream Connectivity Work Group
For their commitment to improving aquatic
organism passage across the state.
Thanks to the members of the Connectivity Work Group for their hard work on behalf of
Maine’s streams, and
Thank you for attending this session.
I wish you well in your restoration efforts.
45