I've previously
blogged about the WWII Memorial planned for Winthrop Street. The
Medford Transcript ran an
editorial in this week's paper entitled, "Where to put it?" After running a callout box on the front page above the fold asking residents
to submit their feedback on where the memorial should be, the Transcript received, "nearly a dozen calls, e-mails, faxes and
hand-written letters." From this they conclude that, "It's obvious people in the city are also split as to where to keep the
monument."
OK, let's run the numbers.
Population of Medford: 55,765 (2000)
Registered voters: 29,253 (1994)
Circulation of the Medford Transcript: 6369 (2002)
Number of respondents: 11 est. (actual "nearly a dozen")
Number of complaints to Robert Penta: 5 est. (actual "several")
Statistically speaking, I think that conclusion is full of crap.
The Transcript also says, "It's time for the mayor and City Council to come to an agreement about the memorial and its
location."
The problem is, the location has already been decided. It's going to be on Winthrop Street. The City Council had
its chance over the years to be involved, and they blew it. In my opinion the Transcript is just as guilty of politicizing
the issue as Robert Penta is, by manufacturing a story based on a few phone calls Penta received, and blowing it up into an
issue where we suddenly need to decide where it should go. Never mind that they've already cleared the trees from the Winthrop
Street location.
The Transcript also talks about readers who suggested alternative locations, notably Oak Grove Cemetary, City Hall, and
Royall Park. I've already talked about why I think Oak Grove is a terrible idea. But here's another reason. Playstead
Road, on which the cemetary is located, is not a heavily travelled street. Winthrop Street is. You can't tell me that it will
get less visibility on Winthrop Street than Playstead Road. It just doesn't pass the laugh test.
The Main Entrance to the Oak Grove Cemetary on Playstead Road
So to all involved it prolonging the dispute I say this. Stop. Just stop. The memorial is going to be built on Winthrop
Street, so get behind it or get out of the way. To behave any differently is an insult to the brave souls that will be immortalized
on the memorial.
This afternoon there was an informational meeting at the Winchester Town Hall Auditorium entitled, "Study
and Conceptual Design for New Upper Mystic Lake Dam." The meeting was hosted by the Massachusetts
Department of Conservation and Recreation (DCR). The dam in question is located between the lower and upper Mystic Lakes. The dam itself is in Medford, but the lakes
straddle Medford, Arlington, and Winchester. It was built in 1904 to create a water supply for Somerville and Charlestown
and has fallen into disrepair, hence the move by the DCR to fix it.
The Upper Mystic Lake Dam
DCR relied heavily on studies and expertise from
CDM (AKA Camp Dresser & McKee) - a consulting, engineering, and construction firm located in Cambridge, MA. After brief opening
remarks from Paul DiPietro, Mike Galvin, the project manager gave a general overview, and then turned the floor over to Dick
Laramie of CDM. What follows now is my reporting of the presentation.
Paul DiPietro (DCR), Mike Galvin (DCR), and Dick Laramie (CDM)
Two phases of the project have been completed. Two more can be inferred from the information presented. The project then
looks like this:
- Hydrologic & hydraulic (H&H) study of the Mystic River watershed for data relating to the project
- Evaluation of dam and development of required dam safety improvement recommendations and conceptual design of fish ladder
- Design and operations plans
- Construction
As of this time, the first two phases have been completed, and the results were presented this afternoon.
First, the H&H study. The study broke down the Mystic River watershed into its component sub-watersheds: the Aberjona
river, the Mystic lakes and river, Alewife Brook, and the Malden river. The study set two important design criteria - the
flows associated with a "50 year flood" and those associated with a "500 year flood." The 50 year flood levels were modeled
on a storm from October 21/22, 1996. Interestingly, three of the top four flow conditions occurred in the five year period
between 1996 and 2001. It was unclear to CDM whether they were seeing evidence of a generally wetter trend, or if it was just
a statistical coincidence. At any rate, the dam itself must be design to withstand a 50 year flood. There is another mechanism,
a spillway, that is required to withstand a 500 year flood.
The dam actually has a spillway today - it is located on the Arlington/Winchester side of the dam, near the Medford Boat
club beach on the upper Mystic Lake. Even more interesting, the MDC, back when it existed, sold off some of the property in
the spillway, which means there is now a house and a few other structures located in the path of the spillway water. If we
get a 500 year flood, somebody is going to be in big, big trouble.
The presentation talked about channel gradients and restrictions and was fairly technical. Most of the bridges were found
to pose no significant obstruction. The one bridge on the Mystic that was a concern was the Craddock bridge on Main street
in Medford Square. It is the only bridge downstream of the dam on the Mystic that does not allow a wide channel of water.
This bridge had a working lock in it until the Amelia Earhart dam and lock was completed. At that point, the locks were removed
from the Craddock. Another problem with the Craddock was silting and accumulation of debris below the waterline. Dive teams
were sent to inspect the dam, and in December of 2002 they removed these obstructions.
Alewife Brook has a number of issues too. It has two bridges (Broadway and Massachusetts Avenue) that are significant constrictions.
It also suffers from a very shallow gradient which presumably means that water is not as inclined to flow downstream. The
widening of those bridges, while relatively inexpensive (between 1.5 and 2.5 million per bridge), was not judged to be necessary
for the purposes of the upper Mystic Lake dam.
So the conclusion of the phase 1 H&H study was that
- There are no constrictions that are cost effective to eliminate
- It is not practical to reconstruct the Alewife Brook and Mystic River channels
- An improvement to the upper Mystic Lake dam will not adversely affect downstream flood levels
- There needs to be a flood monitoring program
Now let's talk about the dam, and what needs to be repaired. The dam has three mechanisms for controlling water flow: a
"low-level output" channel, the gates/weirs, and the spillway. The low-level output channel is a mechanism below the waterline that sends water from the upper lake to the lower lake.
There are six gates in the dam that operate as weirs. This just means that they are set to a predetermined height with stop logs, and the water flows over the top when it is
high enough. Back in the day, the MDC used to actually insert and remove stop logs from time to time, according to a member
of the audience, but that has not happened in a long time, and they are believed to be seized at this point. I previously
mentioned the spillway - it was designed, in this case, as a last resort for extremely high water flow conditions. In addition,
there are the wing walls (visible in the top photo as the triangular walls leading into the lake from the dam) and the apron,
pictured below.
The Outflow and Apron of the Upper Mystic Lake Dam
The design option that was judged to be the most effective solution was adding one new low level output in the stop log
bay, and the addition of a 30 foot emergency spillway on the Medford side of the dam. However, the apron, wing walls, and
stop logs themselves will require repair. They may also put mechanized gates in two of the existing ones - these would function
as sluice gates. In addition, the supports for the gates and stop logs were the subject of some discussion. They need to be
re-mortared, but were found by CDM to be "true", that is, they are correctly aligned. A member of the audience challenged
this, stating that if they were aligned, the stop logs wouldn't be siezed, and further that if you just stood up there and
looked down at it you could see that they weren't in proper alignment. This issue was not resolved, but is of some concern,
since I suspect rebuilding those structures would add significant cost to the project. There was also some discussion of pre-emptive
discharging. It take four days to drop the water level of the upper Mystic Lake by four feet. In advance of a significant
rain event, the water level could be dropped to create capacity for the oncoming flow.
What is not in dispute is that the apron is in terrible shape. It's clear from the photograph (if you look closely, you'll
see that there is a sizeable tree growing in the middle of it). In addition, there is a substantial accumulation of silt and
debris in the upper Mystic Lake at the entrance to the dam. CDM took sediment samples to determine if pollution levels precluded
using this sediment for landfills, and found that they did not. The only hitch is that you can't dump wet sediment into a
landfill, so it would have to be dried, probably near the dam site.
The existing spillway would be diked off, and a new spillway constructed on the Medford side. It appears that the spillway
would take the form of a four foot deep channel thirty feet wide, and would be located between the gatehouse and the dam.
The roof of the gatehouse is leaking, and needs minor repairs, but the mechanics inside are sound.
Unfortunately, the trees and brush on both banks of the Medford side of the dam will have to be removed, and the area
made flat and grassy. Trees cause a few problems - they can blow over in a storm and cause damage, and they eventually die
leaving voids in the embankment. The dam cannot be repaired without getting rid of the shoreline growth. On the upper lake
shoreline, they'll remove all trees and brush from the red gatehouse to the dam, so pretty much everything you see in the
photo below.
The Shoreline on the Medford Side of the Upper Mystic Lake
The impact is more significant on the lower lake. There is a structure on the access road called simply,
"the tunnel." I'll get into that in a moment. If you turn onto the access road from Mystic Valley Parkway, you can see the
top of the tunnel on your left about halfway to the parking lot. They'll take out everything on the shore from the tunnel
to the dam. In the photo below, you can see the top of the tunnel in the lower left-hand side.
The Shoreline on the Medford Side of the Lower Mystic Lake
Now let's talk about the tunnel. I found this fascinating. The tunnel is actually an aqueduct. The outflow pictured
below does occasionally have a small flow through it. However, the tunnel itself does not end here. It runs along Mystic Valley
Parkway all the way over to Dilboy Field. In fact, they have sent a guy in to walk the whole thing, but the radios don't work
well inside the tunnel, and so they haven't been able to survey the whole system. They did perform an inspection of the part
between the gatehouse and this outflow, though, and found it generally in good repair, with only minor cracks in the brickwork.
The Tunnel
And last but not least, the fish ladder. The project plan includes a fish ladder. Both Paul DiPietro and Mike Galvin
insisted that the fish ladder was part of the project, and it will be built when the project is completed. It will also be
on the Medford side, and I believe they said it would be a
Denil fishway.
After an hour presentation, there was a healthy Q&A session. During this period, some interesting discussions occurred.
A few people took issue with the idea of dropping the upper Mystic Lake water level by four feet. They questioned whether
the DCR really understood the impact of such a drop. For one, a four foot drop will leave a lot of shoreline above water,
and potentially in spawning areas for fish. There are also docks and other structures that may be rendered inoperable with
the (relatively) sudden loss of water. One gentleman, stating that he was a professional meteorologist, wondered how anyone
could really know four or five days in advance that you were going to have an event that would necessitate dropping the water
level. These questions were mostly deflected by the team at hand. They discussed how there are a number of operational procedures
that have not been worked out yet.
There was also discussion about the location of the fish ladder. Laramie had talked about putting the new sluice gates
on the Arlington/Winchester side of the dam. A member of the audience had concerns, since the flow from those gates would
be the strongest flow coming from the dam. Fish find the ladder by following a strong flow of water. So it makes sense to
put those gates on the Medford side where they'll be closer to the fish ladder entrance.
We also learned at this point that Brad Chase of the Massachusetts
Division of Marine Fisheries was in the audience. He stated that DMF would be involved in the design and planning of the fish ladder and its impact once
the project was underway.
And finally, someone asked whether or not the walkway over the dam would be open to the public. It is gated today because
it is a main entrace to the
Medford boat club. DCR was unsure one two grounds: they were not sure of the terms of the lease agreement with the Medford boat club, and they
were concerned about security in a post-911 world. To that last point, I told them that the gate was hardly secure. You could
walk around it at will. In fact, when taking the photos for this story I was sorely tempted to just walk up and take close-ups
of the apron, but I did not, because I'm generally a law-abiding guy. The water level in the lower lake was low enough that
I wouldn't have even gotten my feet wet.
So how much will all this cost and when will it happen? The project is estimated at $2.5M and the best guess anyone could
come up with is that it will be two to three years before it starts. Just the fact that they really don't know is unsettling,
but unfortunately, that decision is in the realm of politics, not public safety or conservation.
There's been a lot of wildlife around the house lately. Yesterday, I looked out my kitchen window and saw this! Can you believe
this guy actually climbed into that steeple or whatever they call it on top of my garage? Do I have a family of racoons living
there? Who knows. I'll have to check it out when Kara and Katherine are out of town. I had to beat them off with a stick last
summer and fall from time to time (not literally) - they've taken a pretty good run at my trash cans. In the meantime, the
cats are spending a lot of time by the front door sidelights, because some dove-like birds appear to be building a nest in
the gutter on the inside of the front porch overhang. I guess spring really is here.