Planning for More Frequent River Flooding—October 9, 2018


Okay, so we’re really happy that
you’re all here with us today. And I’d like to go ahead and
introduce our moderator, Janet McCabe. So Janet is the Associate Director
of Policy Implementation for the Environmental and Resilience Institute
at Indiana University.>>Hi, everybody and thank you so
much for joining us today. I’m really pleased to actually
be here in Bloomingtons running Andrea on-screen,
to a help moderate this webinar today. We are thrilled to be providing these
webinars, for you guys especially for cities, and towns and
local government officials. And look forward to your participation
in our future webinars and also for your suggestions on how to make these most
useful to you including specific topics. Today we’re gonna be discussing Flooding. This was probably the number one or
number two topic that Andrea and I have heard from mayors and
other local officials as we’ve gone around the state as being something
that is very much on their mind. That is related to the kinds of
environmental changes we are seeing here in Indiana. So today we have a couple of very
experienced speakers to share with you information about
the flooding issue and about things that our cities can and
are doing to address those. I’m gonna quickly introduce our two
speakers, give a little bit of information about them, thank our sponsors and
then we’ll get going. So here’s some introductory remarks, our first speaker is going to be Dr.
Alan Hamlet. Dr. Hamlet is the lead author of
Indiana’s Past and Future Climate, a report from the Indiana
Climate Change Impact Assessment. He is an Assistant Professor
in the Department of Civil and Environmental Engineering and Earth
Sciences at the University of Notre Dame. Among many areas of expertise
related to climate, Dr. Hamlet’s main areas of
expertise is Virology. Which is the science concerned with
properties of the Earth’s water, especially its movement
in relation to land. So obviously, very relevant expertise for
today’s topic. Our second subsequent
speaker is Donna Price. Donna is a certified
Flood Plain Manager who has worked for the city of Indianapolis for 30 years. Past positions with the city and given
her experience with drainage inspection, plan review, and
managing drainage and levy projects. In 1995, Donna became the drainage flood
plan manager for the city of Indianapolis. We have a wide variety of
people joining us today. And so you’ll be able to see there
the participation that we have. So we’re thrilled that word is
getting out about this webinar series. Please feel free to tell your
friends if you find this useful. I want to ask if Mayor Gessaman
has joined the call. We we’re hoping he would have a few
minutes to share a few thoughts in regards about the flooding issues
that they have had in Portland, Indiana and
I think we don’t have him on the phone.>>Yeah, and if you are on the phone
Mayor, you can unmute yourself and start speaking.>>All right,
well maybe we’ll get him another time. I wanna thank
Accelerate Indiana Municipalities, just one of our cosponsors for
this series. And many of you probably
are very familiar with AIM and the support it provides, the voice it
provides to municipal government in Indiana with more than 460 cities and
town as members. I also wanna thank the Association of
Indiana Counties, which has been working since the late 1950s for the betterment
of Indiana county government. We really appreciate their
support of this webinar series. Lastly, just to remind everybody, the Environmental Resilience Institute
here at Indiana University, is committed to providing resources
to cities, towns, county officials, and others who can benefit from
learning from one another. About environmental resilience,
climate change, sustainability programs, and
all kinds of resources in schools. You see on this slide, several theme, projects that we are working on here,
intended to assist you. And if you have any
questions about our tools, please go to our website and
check those out. I wanna do a special shout out for
the 2019 Resilience Cohort project, where we will be providing, along
with the IU Office of Sustainability, Technical assistance and
trained extern capacity for cities interested in completed
a greenhouse gas inventory during 2019. It’s a very exciting project, we already have several cities that
are eager to go forward with this. And we’d like to add your city to
that list if you are interested.>>It looks like Mayor Gessaman
has joined us today. Are you there Mayor? Okay, well,
maybe we will get him later in the call.>>Okay, all right, with that I think
we’re ready to go to Dr. Alan Hunt. So Alan, we’ll ask you, Hamlet, I’m sorry, we’ll to share in your screen and
take it away.>>Okay, I will go here. All right, I think we’re up. So thanks very much for inviting me. I’m going to speak today on the effects
of climate change on flooding in Indiana. And specifically to address
the increasing risks that we see in a non-stationary environment,
both in the historical context. And also looking forward multiple decades
towards the end of the 21st century. So as we move forward in time, there are three very important
obstacles to sustainable and resilient human systems and
particularly in urban environments. So we face the challenges of aging and
inadequate infrastructure. Many of our sewer systems for
example date from the 19th century, and are completely inadequate,
even in their original form but are very old and kinda falling apart. We have rising human population,
particularly in urban settings and this is true throughout the world. We currently have about 50% of the world’s
populations living in cities and over the next 50 years or so,
those projections suggest we may have as much as 70% of the growing
population living in cities. And third, as has already been
alluded to is that climate change is changing the statistics,
both of precipitation. Which affects urban storm
water management and other important impacts throughout
the Midwest and Indiana. And secondly, we also expect to
see increasing river flooding, as I will show you in just a moment. So here are some projected changes for
the Midwest. So these are on a larger
scale than just Indiana. But these look very similar to what we see also in the Indiana Climate
Change Impacts Assessment. So in the top row here, we see
precipitation changes in percent by month. And so along the x-axis here,
this is from October to September, the traditional water year. And let’s look way out here in the 20-80. So, when we made simulations using
global climate models, and for the 2020s, the 2050s, and the 2080s. So let’s look at the 2080s first. What we see is a strong increase in
precipitation of about 25 or 30%. So this red line is
showing the impacts for the highest indention
scenario called RCP 8.5. And then, the green trace is for RCP 4.5, which is a sort of middle
of the road scenario. All right, so we have two different levels
of greenhouse gas accumulation, but all of them are showing strong increases
in precipitation in the winter and the spring. Whereas in the summer months over here,
we see small declines and considerably more uncertainty,
particularly in June and July here. We see about half the model showing wetter
conditions, half showing drier conditions. So this suggests that in summer months, we may see things that vary quite
a bit from decade to decade. We may see extremely wet conditions and
extremely dry conditions, both of those in the future. Whereas for the winter and spring,
we see a really strong signal, almost all the climate models
say that it’s gonna get wetter. So, if we look back at the 2020,
we essentially see the same pattern beginning, basically it strengthens
through time from the 2020s to the 2080s. For temperature change, once again, we see extremely strong changes
here particularly in the Midwest. The Midwest is often assumed not to
have big climate change impacts, but this is actually not the case. We see impacts in the Midwest
that are more than two degrees see higher than the equivalent numbers for
the globe. So the Midwest is actually something of a
hot spot in terms of temperature impacts. The largest impacts over the Midwest
as a whole are in the summer time and also there’s some large effects
in the middle of the winter. And for Indiana, this signal is a bit stronger in
the summer than it is in the winter. And again, some of these scenarios,
the highest are on the order of 10 degrees Celsius warmer on average,
so that’s 18 degrees Fahrenheit
warmer on average. Those are gigantic numbers, and
are a really important impact pathway. In particular, we expect to have
less snow in the future, and more rain falling in the wintertime. And as we’ll see, this can have profound effects on
flooding that occurs in the wintertime. All right, so we expect to see wetter and
wetter in winter and spring, drier and mixed regime in summer. It could be wetter and drier at different
times and very strong increases in temperature, particular towards
the end of the 21st century. So in addition to these future
projections, and I’ll be showing you some projections of river flooding in just a
moment associated with those projections. We also see a lot of evidence from the
historical record, that the probability distributions of both precipitation and
river flooding are changing. Just to give a few quick examples of this. This is a picture of my son and one of our
neighbors canoeing on our park after 1,000 year rainfall event in South Bend which
occurred in middle of August in 2016. So we received about 8
inches of precipitation over the city in about 24 hours. And that corresponds roughly
to the 1,000-year event. So there was extensive
groundwater flooding and damage, particularly to finished
basements in South Bend. And you can see that the groundwater table
here in the park is very, very high. And so this persisted for
a number of days at this level, actually. In of February 21st of 2018, we had an extreme river flood
in the St Joseph River. At the beginning of this storm, we had about 18 inches of snow on
the ground in some places in the basin. A warm, wet storm came in, basically an atmospheric river
coming up from the Gulf of Mexico. It first melted all the snow, and
got the soil nice and soaking wet, and then we had about five additional
inches of rain over three days. This resulted, by the numbers,
in a 2,500 year flooding event. So here I’m showing just north
of downtown South Bend here. But the river stage was incredibly high. And, just to put this in context, so
here are the observed peak flows from the USGS records,
that’s basically the blue trace here. Here we fitted a probability
distribution in orange so you can see the fit is quite good. And here is the 2018 event. So this is stream flow peak
stream flow on the y axis and probability of exceedance on the x axis. So you can see that this event was so far
off the chart that it doesn’t really even look like it belongs to this
probability distribution. Now, again, we can’t really ascribe
this single event to climate change, but certainly suggest that the statistics
are dramatically changing. Just I couldn’t resist showing
this picture of my basement, this was in the February event. So when the river was so high all of
the sewers were trying to back up and I have a bull valve in my floor here which
is we could sort of see it right here. It’s shut so all the ground water is coming in
through the cracks in my basement. And because it can’t get
out through floor drain, it basically filled up to knee level. And so getting a pump big enough to take
care of this actually took some doing. And these impacts again were quite
wide spread throughout the city. Lastly, if we look at more moderate
events, we also see a strong signal. So observed changes in peak annual flows. And again, in the St Joseph River at
Niles, if we segregate the record of these peak flows, so
these are the largest flows each year, so called annual extrema or
annual peak flows. And they start in around 1930. So if we take the pre-75 data and
the post-75 data, and look and see if the mean is statistically
different, it’s very strongly different. So with 99% confidence, about,
we can say that the mean post-75 is higher than what we see
in the early part of the record. And so this is quite a significant change,
just not only do we see more, so look at the number of events
above 15,000 CFS for example. In the early part of the record,
we see two and then the latter part of the record, one, two, three, four,
five, six, seven, eight, nine. So, clearly, some large changes going
on in the probability distributions. All right, and so this shows
the cumulative deviation from the mean, which I won’t describe in detail. It just shows that we have a preponderance
of above-average conditions here and below-average conditions here. All right, so given the observed changes
that we see in the historical record and the projections for the future, when we
put those two together, it’s evident that there are new paradigms which are needed
for the management of natural resources. And the design of infrastructure in
what is clearly a highly non-stationary environment So Milly et al. Put this well,
the title of their paper was, Stationarity is dead,
whither water management? And their point was that this practice of
looking backward at the historical record, while it has served us well in the past,
is now not serving us. Because we cannot plan for
conditions in the historical record which are going to be quite
different in the future. We need to plan for a changing future. So one of the most important elements of
this and something that my lab has devoted a lot of time to is quantifying
the future extremes. If we can quantify these
extremes then planners and engineers can use this information
to design infrastructure or policies that cope with
these changing conditions. So, one of the ways that we do this is we
use output from global climate models. And these are the tools that we use to
project, for example, the temperature and precipitation changes that I showed
you at the beginning of the talk. We run these temperature and precipitation changes then through
what are called hydrologic models. You can think of these as a translator
between climate and water information. So for example, using these models we can
predict the peak stream flow in rivers. So similar to what we do
with historical records, we take the simulations of the future,
we fit probability distributions and then we can estimate things. For example, we can estimate the changing
100-year flood in the future, or other statistics of interest. So this is a case study that we
have worked on where we examine 20 watersheds throughout the Midwest
which are shown here. I’m gonna focus on several
of these in Indiana, so 19 here this is the Wabash River
at Mount Carmel. And then 18,
this is the Wabash River at Lafayette. So I’m gonna focus primarily
on those two rivers. All right, so we chose these basins because they show a
wide range of hydrologic characteristics. And we wanna see how these projected
temperature and precipitation changes that I showed you at the beginning of
the talk ultimately affect flooding. All right, so here are the 20 watersheds. Again, 18 and 19 are in the Wabash here. So what we see typically is there
are kind of two classes of watersheds, one which is fairly nicely
characterized by the Wabash results. So because we see wetter and
warmer conditions in the winter and spring we see more precipitation as rain. We see increased runoff in the winter and
spring. But you’ll notice that this is being caused by having a lot
of more rain as opposed to snow. So again,
we’re seeing increased annual flow. And at the time of flooding, which is
often, can be actually any time in here in the historical record, we’re typically
seeing increases in flooding. So there are a number of
watersheds throughout the basin, throughout the Midwest Basin,
that look like this. So many of the watersheds show
increasing flood risk we would expec, based on these monthly numbers. Now, that said, there are another
group where we often see decreasing flood risk and so what’s happening
here is that these basins typically flood in the springtime due to
very heavy snow accumulation. These are mostly northern basins. And so as the climate warms, even though
we have increasing precipitation, it gets so
warm that we don’t have as much snow, and therefore the spring peak flooding
actually goes down in these watersheds. But in Indiana, it’s mostly the previous
case where we have increasing risk in the winter and the spring. All right, so we’ve summarized all of these basins
by calculating the 100-year flood. And so what you see here are there
are the two emissions scenarios. The high one, RCP 8.5. So that’s the most extreme. And then RCP 4.5 are shown in the green,
also the olive colors here. And what’s showing here is a change in the 100-year peak flow in percent. And each of these, so looking here at the Wabash at
Mount Carmel, just as an example, each of these sorta salmon colored
dots is a single climate model. And then the average of all those
climate models is shown in the red dots. So in this case, we’re seeing, perhaps, a 35% increase in the 100-year flood and
this is for the 2080s. So you can see that the Wabash
is kind of a poster child for increasing flooding in the region. And we see a lot of basins are showing
increases, maybe from 10 to 15%. But the Wabash is much, much higher. We didn’t, in that study, look at
the Saint Joseph River, but we did it afterwards, because there were a number
of people that were interested in this. Again, the Saint Joseph
is quite sensitive. We see on the order of a 45% increase in the 100-year flood by,
again, by the 2080s for 8.5, RCP8.5 emissions scenarios. All right, so focusing in on
the Wabash now just to give a concrete example of how these risks can be
interpreted and used in planning. We’ll estimate several key quantities. So, let’s imagine, for example, that we have designed some infrastructure
to withstand the 100-year flood. And let’s say that we have
a design lifespan of 30 years. So this is the timeframe
of someone’s mortgage. If we design to that standard,
the likelihood that there will be a failure based on a stationary
analysis would be about 26%. In other words,
over 30 years there’s a 26% chance that we will see a flow above the 100-year level. So that’s actually pretty high, isn’t it? Even for the length of someone’s mortgage,
that’s a pretty high number. So insurance companies are very
well aware of these kinds of risks. All right, but if we consider the
stationary case where we again design for the historical 100-year flood,
now we see this curve. So again, for the same design lifespan
of 30 years, we now see almost double the risk due to this non-stationary
conditions going through time. So this calls attention to
the challenges that we face. We have problems enough with
flooding based on extreme events that we have seen so far, but they
are projected to increase dramatically. And if we look at longer
lifespans of infrastructure, and many of our critical infrastructure
in cities has a very long life span, these risks are even more extreme. In the future for example, if we
design through the old 100-year flood. We might see nearly 100% risk of failure
for a 70 year old design lifespan. So these impacts I hope convinced
you have major management implications as we go forward
in a non-stationary environment. And some of the important impact pathways
that we need to consider include urban storm water management. We have seen, not only in Indiana cities,
but also throughout the midwest and in southern Canada extreme events
related to urban storm water management. For example, in Toronto in 2013, they
experienced the single largest natural disaster in Ontario’s history in a one
day thunderstorm that cost $900 million. So these are the kind of impacts
that we’re talking about. They are non-trivial. They are extremely damaging. So we expect, as I have showed you, to see
in many cases increased river flooding. And the need to revise flood
control infrastructure and operating policies relating to,
for example, dams and levees. Dam safety is a concern. Just as we saw in North Carolina, with the
increased hurricane risks that they had, there were a lot of concerns
about dam safety there. Transportation impacts are very important. And so if we see extreme precipitation
like what we saw in South Bend, this can cause flooding in low lying
areas, which can be life threatening or cause serious safety issues
just to moving traffic. Floodplain development policies and flood
insurance, and so our next talk we’re gonna hear in detail about that, and
emergency management procedures. And there are many ecological impacts,
perhaps one of the most important of them is nutrient impacts to the Great Lakes and
Gulf of Mexico. If we see reduction in snow pack which
effectively armors the landscape in the winter time. And we see more rain occurring in
these extreme storms in winter, we are very likely to wash a lot of
sediment and nutrients into our rivers. Which then ultimately make
their way to the Great Lakes, the Gulf of Mexico, and are causing
huge problems related to hypoxia and harmful algal blooms,
just to name two impact pathways. So I will stop here, and we’ll have
time for questions later I think. Thank you. Okay, I think I’ve stopped sharing.>>Dr. Hamlet, in all your graphs,
the orange shaded area surrounding the lines,
what does that mean?>>Okay, thank you. So, we have, each global climate
model gives us a slightly different realization of the future
temperature and precipitation impacts. So that shaded area represents
the range of values from, in this case,
six different climate models.>>Okay.>>So the dark red line is
the average of those six, and then the range is shown
in the lighter color.>>Okay, thank you.>>Thanks for clarifying that. Janet, I think you’re muted. I’m not hearing you.>>Okay, there we should be. Sorry about that. Getting used to clicking
all these little buttons. Alan, thank you so much. I think you’ve done a great job of laying
out for people how much more information we have about what we can expect in
the future for flooding and storms. These are issues that local officials
deal with all the time and prepare for all the time anyway, but we’re going
to be needing [SOUND] to do that more. So, so one question that people
might reasonably have is, okay, what should we be thinking about doing? How do we take this information and
turn it into appropriate policy, budgetary decisions,
infrastructure decisions, and that sort of thing, which is what
local government does every day. So we’re gonna turn now to Donna Price
from the city of Indianapolis. Who is gonna share her experiences
over a number of years working with the city of Indianapolis to address and
start anticipating some of these issues. So Donna, I’ll turn it over to you and
you can share your screen. Are you there, Donna?>>I think you might be muted,
let me try to unmute you here. Okay, you should be all set now.>>Okay.>>There we go.>>Yeah, something like that,
wait a minute. Okay, all right.>>So we’re not looking at PowerPoint yet.>>No, I know.>>Okay. So you may need to stop sharing,
there we go.>>There we go.>>Okay.>>All right, I knew I’d get it. Okay, welcome everyone, and thanks for
joining in on this webinar. I’m Donna Price. I work for the city of Indianapolis. I’ve been doing floodplain management for
a long time. And so I thought I’d talk to you a little
bit about floodplain management and mapping. First of all,
what kind of flooding do we have? And where, and why? Well, there’s riverine type of flooding,
and flash flooding, when you get the downpours and
it’s like a monsoon outside. Infrastructure can’t
necessarily handle it. But then there’s also just
localized drainage flooding, and part of that is based on how
we design our infrastructure. The flooding occurs, of course,
in floodplains for the riverine type of flooding, but there’s also just low lying
areas and structures next to water bodies. And in reality,
it can flood just about anywhere, and it does, and I’ve seen a lot of it. Why does it flood? Well, extreme rain events, of course. There’s encroachments in the floodplain,
combined sewers, obstructions, climate change. Because as Alan alluded to, we have
increase in frequency of rain events, increased intensity of rain events,
and duration. And the weather patterns
are just changing, and we need to take that into consideration. There’s also timing and peak flows,
as Alan kinda talked about. It can rain in Madison County, And
it won’t hit the White River here in Indianapolis at Nora Gauge for
about three days. So if we’re getting
a huge storm at the time that the White River is
draining the upstream basin towards Indianapolis then that’s gonna
cause a lot of flooding as well. And I kind of alluded to
the infrastructure limitations. A lot of people don’t know this, but
Indianapolis was actually constructed on a swamp and we have a lot of
basement flooding, a lot of backups. I thought I’d just show a slide
of direct regulatory floodplain. Though the floodplain, and I used these
terms interchangeably all the time, but the floodplain really
consists of the defined floodway. Right here, and
the flood fringe, right here. I kind of explain it to folks that
the floodway is where you have your current and your velocities, and
it conveys the flow, downstream. The flood fringe is where
the water kind of has to hang out until it can get convey within a floodway. So, the encroachments in a flood way can make flooding worse downstream. Now, the state of Indiana has
a much more designed floodway, because FEMA would allow
a one foot surcharge. The state does not. It allows anything less than 0.15. That’s as much as you can
increase a base flood elevation. So just a little Marion County data. We have 402 square miles and
we have 346,000 parcels. The parcels in the floodplain
are about 32,000. And there are about 6,535
parcels within the floodway. The floodway, having the greatest risks,
so wise in property. There’s about 34, 000 acres, and
about 10,000 acres, so that is Floodway. We had about 22,000 total
structures in the flood plane, and 9,694 primary structures
in the floodplain. So those are homes, and we used our GIS and anything 800 square feet or larger, we consider to be a home or
commercial building in the floodplain. We have about 6,000 flood insurance
policies here in Marion County. And I say Marion County
because zoning is countywide. So we have actually excluded cities
that we do zoning permits for and floodplain development permits. So those exclude cities for and speedway. Yeah, where they have that little track,
you know? So, one of the things that we’ve been
doing since about 1999 about 1999. And we’ve been working on
updating our floodplain maps. There are some streams where the maps, they’re just not accurate. Discharges were determined I
always say coordinated discharges. You know, a bunch of engineers went to
a hotel, got in a room and said, yep, I think this is how many cubic feet per
second is gonna go into this channel. And so they mapped the floodplain
based on that discharge. Well those discharges are changing. So the reason for the accurate
flood plane mapping is, because I swear, I do not think that we had
a flood until I took this position. I know I’m wrong. But we have to respond to the rising
cost of flood disaster and increased flood damage. FEMA is moving towards actuarial rates for flood insurance instead of
the subsidized rates for legally established nonconforming uses,
or those structures that were built before the city entered
the National Flood Insurance Program. We need to accurately administer
county floodplain regulations and we need to guide new development or
redevelopment and try to make sure that
they are gonna stay safe. So what this means for us, Is,
we need to identify the flood risk. So the property owners and community can
reduce their damage, potentially, and be prepared. We need to encourage
developers to build so that they will not,
they’ll look like this, and not like this. So we decided that we would determine the
flood risk in areas where it wasn’t shown. We would update and correct previous
delineations of flood risks. And convert approximate
areas to detailed study so that the Department of
Natural Resources Jurisdiction limits and base flood elevations are already
identified for property owners. One of the things that we did is, [COUGH]
the Department of Natural Resources, their jurisdiction starts
at mile square water shed. We have floodplain areas
that were mapped floodplains on a flood insurance rate map that
were less than a mile square. So, those some of the areas
that we concentrate on, because is somebody wanted to put
an addition on to their house. We had to make sure that they were
not gonna build it in the floodways. So, we did a lot of studies. So as I said,
we’ve been doing these studies since 1999, we are a cooperating technical
partner with FEMA, so we could use federal grants and
not just city funding. And when you get the federal grant it’s 25% match and FEMA takes care of 75%. So we studied about 183 of
400 miles of stream so far. Actually that number’s probably going
up since we’re still doing some more. Retained floodplain mapping based on redelineating the floodplains
using 2009 topo. We updated computer modeling methods,
flow amounts, discharges. Reviewed the preliminary maps that FEMA published to make sure
that the data was correct. We did that several times. And we also removed high ground. The maps that we adopted in
2016 were the first map that actually used 2-foot
contours to delineate. Before, it was like 10-foot quad maps. So I just threw this one on as correction. So what you see is the floodplain in 2001, it’s this blue shaded area. And then this line after we did this
study is the new floodplain area. This was the floodway in 2001 in yellow, and then the black line
is the new floodway. And why this is important is because
you see all these houses right here? Well, because our ordinance,
if those are substantially damaged, which means they’re damaged 50% or more at these existing market value of
the structure, they can’t be rebuilt. Because they’re in the floodway,
and that’s a high risk area, and our ordinance does not
allow new construction or substantial restoration of damage,
substantial additions, substantial improvements
within the floodway. Because the whole idea is to try to
keep people out of the floodway. And then so
this higher ground was actually removed. It was included in the floodway before,
but now it’s been removed. So here’s another example of
corrections for Wildcat Brook. This was originally a Zone A,
which means it hasn’t been studied. And so we went ahead and studied it,
and so then it changed to a Zone AE. And so the light blue shade up
in here was the old floodplain. And then the heavy blue
line is the floodway. And it was calculated so future developments may not pay for
their own site calculations. And in this case,
there was approximately 21 structures that was removed from
the Zone A approximated floodplain. So as I said,
this has been decades in the making. So in 1984, that’s when we joined
the National Flood Insurance Program, and the first maps were published then. In 1988, they republished the maps,
and there were two maps, flood boundary and
flood insurance rate map. A little bit of floodplain data
is updated, but not very much. In 2001, we basically just went
from a paper to digital format. And so there was no additional
studies done or anything like that. In 2005, we published 14 panels for where we had done some of the studies. And then in 2016, we put all of the mapping changes
into the 2016 maps. And so everything was pretty much, there
was better data for everything, more or less, especially since we used the 2-foot
contours to help with delineation. And we also revised the flood
ordinance and adopted that. And so
here’s a little summary of the effort. Keep in mind,
we adopted the maps in 2016, but they actually went preliminary in 2014. FEMA money was used for For 93 miles of
streams, and those are shown in pink, and floodplain redelineation for
many remaining streams. And then the city used money for
about 90 miles of stream studies, and those are shown in green. So we’re getting there,
it’s taking awhile, but we’re plugging along slowly but surely. So what happened with those? The whole goal, our whole goal here in Indianapolis
is to accurately reflect the risk. So what does that mean? That means some people go
into the floodplain and some people come out of the floodplain. So we were able to remove
4,256 structures, but we added 2,900 into the floodplain. But it’s reflecting the real risk,
and that’s what we wanna do. So what? Well, the risk is more
accurately shown now. So houses are elevated and they stay dry. If they’re not, they may get wet. The flood elevations are more realistic
and the delineations as well. We have defined floodways now, more
defined floodways, and DNR jurisdiction, so individuals don’t have to hire
engineers to make these determinations. And the base flood elevations
are more accurate, so they can be elevated preferably. Now, the state of Indiana requires that you build 2 feet
above the base flood elevation. So there is some, Extra freeboard to make sure that you’re high
enough in case there are changes, or the discharge is maybe
a little bit higher than what was anticipated or what was approved. So flood insurance,
this is kind of our timeline. I scoped these maps out in 2004 with FEMA. It was during a public meeting for
2005 mapped option. And a number of things caused delays. One of them was Hurricane Katrina
because of the levee breaches. And FEMA decided they wanted to
start looking a little bit more into levees and
how to rate areas that are behind levees. And so they came up with
a levee certification program. And so, of course,
before we adopted any new maps, we needed to look at all of
our levees in Indianapolis and determine if they could be certified and if they were from providing
protection that was necessary. So we did do that. After several revisions,
preliminary maps were released for public viewing in April of 2014. We had public open houses to
view the new maps in July. And then FEMA has published notice of
the new maps in its Federal Register. In 2015,
we went through the 90-day appeals period. DNR and FEMA then reviewed the appeals and
made any necessary corrections. We worked very closely with DNR and
FEMA on FEMA’s revalidation letter for
previous issued letters of map change. FEMA will issue what’s called
a letter of map amendment. And that is basically saying,
FEMA, you’ve made an error, and my house is high enough and
it’s not really in the flood plain. They’ll also issue Letters of
Map Revision Based on Fill. If fill would choose
to elevate structures. And then when you complete hydraulic and
the hydrologic studies, they actually do a letter of map revision P,
which stands for physical. So, the Wildcat Creek that I showed
you in a couple of slides ago. That was a typical letter of map revision, because it defined the flood way and
the flood fringe limits better. So in October of 2015, FEMA and DNR issued what’s called
a Letter of Final Determination. That’s when they give you
a six month conversion timeframe because you have
to have the map adapted by April 19th of 2016, and
the ordinance adapted. Because that is the date that is
going to be published on the map so they give you that date. Now, this was particularly
challenging at this point in time because we got the letter
in October of 2015 and we got a new administration
in January of 2016. So the mayor had to appoint
new board members and things like that so it was a real
huge push to get these through. So, we revised our flood ordinance, and I just put a few things in here
about what we put in the ordinance. We have adapted an effective
map date in the ordinance. We also are prohibiting critical
facilities in the floodplain now. So, things like nursing homes,
day cares, schools, and a handful of other
things are not allowed in the floodplain because we need
to keep those folks safe, and we wanna keep our
first responders safe. So from here on out we’re not putting
critical facilities in the floodplain. We are requiring compensatory storage,
it’s one-to-one for the time being because we
didn’t require it before. So to get a one-to-one compensatory
storage that was a pretty good thing. And that helps to mitigate
the displaced floodwaters. We’re requiring bonds for
elevation certificates, if the structure requires
an elevation certificate. And we have a stream protection corridor. The ordinance was approved by the City
County Council on April 11th of 2016. And when do you think we’re gonna
complete our mapping initiative? Well, that would be never. Why? Because rainfall events are changing,
floodplains are changing, technology’s improving. Risks are changing,
there’s new variables and uncertainty. Just like what Alan was talking about
with we’re gonna see temperature changes, we’re gonna see climate change,
we’re gonna see precipitation change. So we really need to be thinking about
focusing on the future and adapting and utilizing the tools that are out
there to protect our citizens. What are the benefits? The risks are accurately reflected. Costs to improve maps are much less
expensive than the potential damage. We have improved response and recovery. We’ve used these maps and this new mapping to revise
our flood response plan. We’re doing a depths risks map so
that we can see at any given time, with any rainfall, that what
transportation routes are available, what transportation
routes aren’t available. We also have updated our multi-hazard
mitigation plan for the future. Whatever you do in your community, it
definitely has impact on flood insurance. Having that two-footed freeboard
above the base flood elevation makes folks’ insurance policies a little
cheaper, so that’s very helpful. And we also can determine the need for
a future flood reduction project. We’ve got a big one going
on on the north side it’s called Indy North, and it’s expensive. We’ve been working on it,
well as one of my coworkers says, it’s old enough to drink. We’ve been working on it for a long time,
and its cost us $28 million. But it’s gonna take a large
area out of the floodplain, and hopefully that will happen in 2020 or
2021. I don’t wanna predict cuz I’ve been saying
the wrong year for a long time now. So with that I’m happy to
answer any questions, and turn it over to Andrea, and Janet.>>Thanks, Donna, that was great. And we had a couple of questions come
in during Donna’s presentation that I think we touched on towards the end,
which is that your floodplain mapping project seemed to be still looking at
current information, as opposed to looking forward using the kind of
information that Alan talked about. We also had a question come in
about the kinds of things in your zoning ordinance upgrade
including green infrastructure and things other than just
restrictions on property. So you touched on those a little bit. Donna, to see if we can
maybe get a summary or a copy of the Indianapolis
ordinance that we can post online, get out to people so
that they can look at those things.>>Sure.>>So
in the few minutes that we have left, Andrew can we unmute people and
see if there’s a question? Or how do you want
people to ask questions?>>So we have few questions lined up in
the chat box so we can start with those. And then, we’ll get through maybe one or
two of those and we’ll open it up. And you are able to unmute yourself,
if you just hover your mouse over the zoom window you should
see an option to unmute yourself. But we can start with
a question from Kimberly. She says, it seems like Indy’s
remapping of flood is going backwards, more structure is taken out than put in. You’re using recent data but
not looking at the future. Are there other ways that you
could make changes to address and incorporate future information, Donna?>>Well,
we do take a pretty conservative approach, but we also have to
follow the guidelines for the engineering that DNR and FEMA require. So. Working towards trying to
figure out how to incorporate the future rainfalls
into the current mapping.>>Okay, great. Another question we have from Joann is,
has the city considered adopting stronger ordinances requiring existing or
new structures being developed on or near the flood plains to incorporate green
infrastructures storm weather management. You can only do so
much through hard-structure regulations, replicating and/or replacing natural
hydrologic function through on-structure and on-site green infrastructures
from modern management would produce multiple value impacts.>>Okay, I’m not sure exactly
what the question was. Can you ask it again?>>Yeah, I think she’s asking
if you’ve considered green infrastructure in flood management and,
>>We do. Yes, we do consider green
infrastructure in flood management. In fact, department of public works,
we as a city, put green infrastructure in, [INAUDIBLE]
with floodplain management, yes.>>So, I have a question for
Alan or Donna, or anybody else that’s on the call who might
have an answer, which is it sound like it was a long effort, and laborious
effort by Indianapolis to do this work. And we don’t really have time or
money for every city to go through, or county to go through this kind of process. And so I’m wondering,
where there are efficiencies, whether it’s through states for
the DNR, whether it’s through FEMA, regional watershed
management organizations. Are there opportunities that people know
of, out there, to do this more at-scale, rather than each city having
to take this on, themselves.>>So, I can say a little bit about
the climate change scenarios. One of the things that we often try to do
is create regional scale resources that can be delivered. For example, we downscaled the global
climate models over the entire Midwest. We ran the hydrology models, but
when we did the Indiana assessment, we really just chopped out the grid
cells that were in Indiana. So this allows you to do
a multiscale analysis. So for example, you can zoom into a city,
or a county or state, or whatever it is, but the resource is produced in a much
larger scale to take advantage of those of the economy of scale involved in
doing a study just once over a big area. So we think that has a lot of value. So for example, as a result of our study, we were able to share data on
the White River with consultants who were working on understanding
the changing flood risk. And I think those will ultimately make
their way into Indianapolis’s planning, but I think it’s a long process of sort of developing new procedures for
estimating the risk. And one of the reasons we don’t see
a lot of municipalities right now, looking forward as opposed to backward, is
because there’s not a well defined way of characterizing these future risks that is
well established in professional practice. And in many times, what’s wrong is that, there’s a perception of professional risk
of doing something new and different. And so people need to become comfortable,
and have input into how these things are done, in a way that they feel
that they’re professionally protected. So if you look backwards and calculate the
hundred year flood, there’s a manual for how you do that, and
people don’t feel uncomfortable with that. But when you look forward
using a climate model, they become less certain
about what that means.>>That’s a really good point. At the risk of filling up your inbox, Allen, is there are people on
the call here who are interested in this information about their county or
their city. Is that something that can be produced?>>Yeah, we actually have a lot of
that from the Indiana climate change impact assessment. So for example,
we analyze the county separately. So there are databases for
your county that can be delivered. So like the pictures I showed of
temperature and precipitation and so forth, those are available at
the county level too, through Purdue.>>Okay, that’s great. I think we are a few minutes past the
hour, we wanna respect everybody’s time, so, we’ll probably call it a wrap there. Feel free to shoot us questions that or
feedback on this presentation. Many thanks to Allen and Donna, and apologies to Mayor Eastman,
we will follow up with him, and apologize. Thank you for bearing with us as we get
used to all of this incredible technology that can bring 50 of us from all
across the state together for an hour, once a month, without anybody having to
put CO2 in the air, to drive somewhere. So, next month, we will be talking
about doing vulnerability assessments, they’ll join us for that. We’ll get announcements out. And Andrea, any last comments?>>No, I thank you all for joining us. And I hope you’ll join
us again on Tuesday, November 13 and
you can register on our website.>>All right, thanks again everybody,
and have a great rest of your day.>>Thanks very much,
I very much appreciate it.>>Thank you.

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