For those who focus on the details of flood events, here is a collection of data points from my travels around the Alewife and Mystic from Sunday into Tuesday. It is important now that we assemble observations from this event and learn as much as possible. Clarissa Rowe will be convening a meeting of the Arlington-Belmont-Cambridge Stormwater Flooding Board for that purpose. But I wanted to collect what I had here.
I will make one summary observation: It is consistent with the timeline below to believe (a) that the blockage at the Craddock Bridge helped elevate the crest on the Alewife Brook and (b) the blockage was perhaps responsible for taking it up the last few inches which led to the worst of the North Cambridge flooding. On the other hand, the fact that water only dropped 8 inches in the 8 hours after the removal of the dock suggests that the contribution of the dock was not overwhelming — the slope of the water level drop at the gauge on the Alewife did not change much as of the removal of the dock.
- On Sunday night, Alewife Brook Parkway was flooded but still passable at 6 on sunday night, according to Steve Kaiser. By 8PM when I came by, the parkway was closed, but water did not appear to be extended across the parkway.
- At 8PM on Sunday night, the gauge under the Broadway bridge was reading approximately 6 feet. The web telemetry was down, so that was just what I could make out in the dark.
- According to a Harrison Avenue resident (North Cambridge near the Alewife Brook), basement flooding on Sunday night was only ground water seepage and his pumps could keep up.
- Water began rising on Harrison Avenue early Monday morning, but with auxiliary pumps he was able to keep up.
- Water rising on Harrison avenue connected with water in his back yard toward the brook in the late afternoon on Monday and at that time, water began rising rapidly in his basement and overwhelmed his pumps
- At 5:00PM Monday, rainfall and Northeast winds were still very heavy.
- At 5:15PM on Monday, all three pumps at the Amelia Earhart dam were roaring away. The racket was impressive from hundreds of yards away. A flood control operator at the Charles pump station stated that all three pumps at both stations had been in operation since Friday night. Three thick plumes of diesel smoke from the Earhart dam confirmed the pump operation. The locks appeared closed at that time. The tide was low, but perhaps elevated by the winds.
- At 5:45PM on Monday, the Craddock bridge was occluded by large dock section approximately 25 feet in length and (visible only later) six feet in width. The section was almost entirely submerged and pressed broadside to the bridge by the current. The rightmost arch of the bridge was fully open but water was dropping approximately two feet as it swirled around the dock and through the bridge.
- Scuttlebut from workers at the bridge on Tuesday suggested that the dock lodged itself against the bridge sometime during the day on Monday.
- At 6:00PM on Monday, the gauge under the Broadway bridge was reading approximately 7.3 feet, suggesting in conjunction with the Harrison avenue observations that somewhere around the 7 foot mark is where North Cambridge neighborhoods really get soaked.
- At 6:30PM on Monday, Harrison Ave in North Cambridge was roughly one foot under water.
- At 8PM on Monday crews arriving at the Craddock bridge made an assessment that give the current pulling under the jammed dock, they lacked the equipment necessary to safely attempt a removal of the dock. DCR struggled into the evening to assemble the necessary bucket truck and crane.
- By 10PM on Monday, the rain seemed definitely to have stopped.
- At 10PM on Monday, the Sunnyside neighborhood had water up to the backs of the houses.
- At 6:30AM on Tuesday, the water level in Blair Pond was still above the top of the outfall pipes to the Wellington Brook, but the driveway to the high school was clear.
- At 6:45AM on Tuesday, the water level on the Alewife Brook was still at the 7.3 foot level although the water on the Mystic seemed to be dropping. (My recollection is not consistent with the telemetry which indicates something like 6.9 inches at at time.) Either way, it appears that the peak occurred at some point during Monday night. This hypothesis is consistent with the shape of the flow curve at the gauge (although that curve is interrupted by a telemetry loss). Comparison of that gauge to the Aberjona guage suggests that as Alewife stream velocity crested on Sunday and slowed dramatically as the crest came down from the Aberjona.
- At 7:00AM on Tuesday, the water had dropped a few inches to expose more of the dock jammed at the Craddock. The current, though still strong, seemed weaker.
- At 9:30AM on Tuesday, the first big piece of the jammed dock came out.
- Just after 10AM on Tuesday, DCR crews with the assistance of Medford firefighters and DOT equipment operators had successfully removed rest of the dock.
- At 10:30AM on Tuesday, the water level had dropped to 6.7 feet at the Broadway guage.
- At 10:45AM on Tuesday, Harrison was clear and basements were being pumped out.
- At 5:55PM on Tuesday, the water level in the Alewife Brook had receded to a little below 6 feet.
- At 6:00PM on Tuesday, the Alewife Brook Parkway was still blocked, but only by residual water which workers were pumping out.
- At 6:15PM on Tuesday, the water level in Blair Pond had dropped just below the top of the outfall pipes. There was no evidence of any obstruction in the immediate vicinity of the outfall pipes.
Your observations much appreciated as comments to this post. For policy thoughts, please comment at this link.
Somewhere in here, the Arlington Reservoir overflowed, and traveled some distance down the Minuteman Trail before adding some of its flow to the Mystic River. It ripped things up pretty well in places, especially around the Park Avenue bridge.
Pictures here, unlabeled.
The first is Waverley Square railroad tracks (under a little water).
Next 5 are Beaver Brook (the camera times are buggy, it was 6:30 PM EDT, Monday)
One showing the debris line at Belmont HS.
Next is flow out of the hill into Pleasant St.
All but the last of the rest, are on the Minuteman Trail, and the last is looking towards the reservoir from the soccer fields near Trader Joe’s.
Several of the washouts alongside the path seen in the pictures have already been filled; it will take more work near the Park Avenue bridge.
About 4 inches of water in the basement, part seepage from underneath and part leakage through wall/floor line. Subsiding by early Tuesday the 16th. Just about every house with same problem, many using pumps into street. We’re on Whitcomb Street, usually very dry. Not this time!
Will, you asked for some specific observations…
First, Belmont should be very pleased: the work done on the box culvert behind the library several years ago prevented flooding of Concord Ave and its homes. A good example of good planning and good execution. I have photos of debris collecting in the brook that I can post or send if you like.
Second, at 10:30am I ran down the Minuteman path at Park Ave and it was not flooded. Around an hour later I was at Fresh Pond, where the path was flooded in the SE and NE bays – 4-5 inches deep in places. At around 12:00 I came back up the Minuteman path and it was filled with heavily rushing water from above Park Street to around 100 feet below the Park Ave bridge, so the flood there started in the late morning. It persisted until at least 6pm, 4-6 inches deep. Erosion is serious and the path is now undercut and sagging in a spot.
Third, my daughter and I took a photo tour of the water at around 6pm. I have good photos of the culvert and stream behind the library as mentioned above, gorgeous cascades of Winn Brook on Clifton Street, the Minuteman path flood, and astounding flows over the falls at Beaver Brook. The mill pond at Beaver Brook was at least 2 feet deep over the spillway (wading in was cold work, let me tell you) and falls were deafening. Again, I have around 60 photos of the entire affair, and can post or share them however you wish.
My usual commute from East Arlington to Cambridge involves walking down Herbert St to Varnum to the Minuteman bike path to Alewife Station. Monday morning, it wasn’t too bad, except for some flooding at the corner of Varnum and Brooks. I had good boots on, so wading through 4″ puddles was OK. The bike path itself was OK, but I took some pictures of the flooding of Alewife Brook, which can be seen at http://www.flickr.com/photos/17694984@N00/sets/72157623641359866/
Coming home that evening was a lot harder. I got to Alewife a little after 7:00, and started down the bike path. I first tried cutting over at Thorndike, only to turn back when I discovered that it was completely flooded, with I’m guessing about a foot of water, more than my boots could take. Next, I tried cutting over at Varnum, the path I had taken that morning, and found the flooding to be just as bad. I ended up walking the bike path all the way to Lake St., up to Mass. Ave., and backtracking, a distance of over a mile, and I was soaked when I got home.
The final comment was the effect that the closure of Rte 16 between Mass. Ave. and Rte 2 had on Arlington traffic. I heard that Mass. Ave. was backed up from Lexington line to Rte 16 on Monday, and was still awful on Tuesday.
While we are all thinking about our basements, roads and commutes, another perspective on the situation is to think about all the animal wildlife now displaced from their habitats due to the high levels of water all around us.
It is worthwhile to be mindful of this when driving around on the roads – you might have already noticed more dead animals on the roads than usual. It helps to be aware of this when driving around right now. Car accidents with animals can cause road crashes, and furthermore the wildlife would appreciate you “giving them a break”. 🙂
The Silver Maple Wood adjacent to the Alewife Reservation and Little Pond. How did it fair in The Flood of 2010? In previous floods Acorn Park Drive flooded, leaving the proposed housing development in the Silver Maple Wood an isolated island. What happened this time? If the housing development is built, what would be the impact on flooding in the office park and elsewhere?
Acorn Park was fully flooded. My view is that this flooding is a result of all of the development in the watershed. Roads and roofs send water into the drain system much faster than soils with the result that all the water arrives at once in the Alewife Basin.
and so, if the rumor that the DEP appeal failed is true, is there no alternative to what now seems the inevitable development on the Uplands? Hard to imagine the impact on future flooding and vice versa! 5 huge buildings…on stilts?!
Hard to say what will happen there! Everything is still up in the air.
I’m in a “100-year flood zone”, & this is the 4th flood since I moved in about 15 years ago… and the worst one.
I’m in East Arlington, right next to the Alewife wetlands. Here’s my basement & yard, at the worst… (Once the yard cleared yesterday, the basement was pumped out by the fire dept, down to a mere 2″)
How do I feel? Wet! Worried! – thank goodness I have a friend to stay with, since the fire dept turned off my electricity when they saw the depth of the water in the yard… but now I have to focus on getting the house, phone, heat etc. back & cleaning up the mess. I do have flood insurance… when will they call back?!
All the homes on Foch Street in North Cambridge, very near Alewife Brook, as well as many of the homes on Gladstone and Newman Streets adjacent, all had wet basements. Homes on the north side of Foch are most vulnerable to flooding, although there have been significantly fewer flooding events in recent years. Several neighbors I spoke to had close to a foot of water. Our home on the corner of Foch and Newman has only had measurable water one other time in the 23 years we have lived here, and we got about 4 inches on Monday to pump out.
Much is going right with flood abatement efforts, but thought you would want to know. We are mostly relieved that it was rain and not snow in this nor’easter.
Our house, on the Tobin School side of Alewife, had a flooded basement for the first time in the 22 years we’ve lived here. After removing out destroyed flooring, our plumbers were amazed at how high the water table under our house has risen. Thousands of dollars to repair, but it feels a bit life New Orleans. How long until the next flood?
Hard to know, Rozann! But they are much more frequent because of climate change and even more so because of all the impermeable surfaces we have built.
Comments are closed.