Maeslantkering: Testing a Storm Surge Barrier

[Nerding, not kayaking]

Once a year, Rijkswaterstaat does a test closing of the Maeslantkering, a massive storm surge barrier on the waterway that connects Rotterdam to the ocean (the Nieuwe Waterweg/the Scheur). Check out the structure in Google Maps. Rijkswaterstaat is the government agency that oversees flood protection in the Netherlands by building and maintaining the complex and highly managed system of rivers, lakes, coastlines, pumps, and flood protection structures. This is necessary because more than 25% of the country is below sea level (protected by dikes). This was one of the last projects within the 50-year Delta Works, a massive flood infrastructure project triggered by the devastating 1953 floods that killed almost 2000 people.

We (Elizabeth, Toni, Sander, Maria, and I) biked the 20+ km from Delft to the Maeslantkering on Sunday afternoon to attend the annual test closure. It's quite the event, with europop music and hoards of politicians in fancy suits. Civil engineering students give guided tours every 10 minutes throughout the afternoon. We took a tour and picnicked on the adjacent hillside with the rest of the crowd.

Panorama of the partially closed barrier, and the hillside of observers. Click to see larger!

Elizabeth and Sander enjoying some good Dutch beer before the closing

Here are some fun facts that we learned during our tour of the Maeslantkering:

• It's painted white so it doesn't expand as much in the hot sun (14-16 cm when white vs ~ 40 cm when black)
• Dimensions: ~25 m high and ~240 m long (like laying the Eiffel tower on its side)
• It rotates on a 10 m "joint" sphere, which is manufactured to 2mm accuracy and lubricated by a plastic polymer (after it started getting stuck on the original teflon layer).
• Constructed between 1991 and 1997
• It still uses same software as when it was built - very simple.
• A computer decides when to close the barrier, and closes when water levels reach 3m above normal levels. Therefore, the closures are triggered automatically to prevent emotions/politics from interfering in its function.
• The closure trigger level (3m) is based on an agreement between many parties, and is expected to result in a closure roughly once every 10 years. With 50 years of sea level rise, this will increase to once every 5 years. So far, the barrier has been closed due to storm surge once, in 2007.
• Every day that the barrier is closed it costs the economy ~$15M in lost income from shipping

How does it work?
The two arms rotate from each side of the river, at a rate of 3 m/minute, until they are ~1 m apart. This small gap just considered a leak. Water is pumped into both arms to fill them with water, lowering them towards the river floor. Then, it pauses for ~1 hour before lowering completely, to allow flow to flush out the track underneath (water moves faster when most of the flow is blocked). This is part of the maintenance, to make sure the tracks don't fill up with sediment permanently. Then, more water is pumped in and the arms lower to the bottom of the river, stopping almost all flow. This animation makes it a bit clearer:

Photo credit

This structure is an improvement on many of the other storm surge barriers in the Netherlands because it lets the river be completely open most of the time. This allows tides and salt water to come in and out, which allow coastal and wetland habitats to exist. However, it still requires having a very controlled mouth of the river, rather than giving the river space to meander/evolve naturally. This works in a place like Rotterdam, which is already highly developed and engineered, but would be a detriment to more natural systems. 

Looking down the north arm, towards the ocean.

View of the closed barrier, from the back.

View of the closed barrier, from the front

We took a much longer route home, making a stop in Hoek van Holland on the coast and biking through the dunes until we reached the town of Monster (yes....) and turned inland towards Delft. Soreness ensued.

Windmills at Kinderdijk (Friday, Aug 22nd)

Guest blog post by Bridget! My comments in [italics], as usual :)

On Friday we woke up early to do my favorite activity – looking at windmills! We decided to go to Kinderdijk, a UNESCO World Heritage site, where a complex of windmills were built to prevent the flood-prone region from flooding. I don't want to bore you with all the history here [THIS IS NOT BORING! People have lived in this region for a long time, and until the 13th century it was dewatered (by humans) using gravity. Since it is naturally a peat bog, dewatering led to decomposition of the peat (when peat is exposed to oxygen it breaks down and releases carbon into the atmosphere), which makes the ground sink over time. Now lower, the region flooded more often. The inhabitants built levees and water storage ponds, where they could store flood water. The 19 windmills at Kinderdijk (built in the mid 1700s) served to pump water from low-lying areas into these storage ponds. Today, the windmills have long been replaced by electrical pump stations and the mills remain for tourist enjoyment.] If you are interested to learn more, you can find a good description on this website: www.kinderdijk.com. 

When we first arrived, we saw a beautiful Dutch couple taking wedding photos in the mill – it was ridiculously picture-perfect scenery. Nena thought she saw the husbands tooth sparkling. At the visitor center, the docent was providing a history of the region. We eavesdropped on the tour (it took me a while to realize that it was in English and not Dutch…), where the man was explaining about the 1953 flood which devastated the entire country. We desperately needed coffee, so we attempted to use the complicated coffee machine, which required carnival tokens. Nena managed to spill all the coffee out of her cup, resulting in only foamy milk and making quite a ruckus.

We signed up for a boat tour (€4.50), which allowed us to float along the canal, boarding and disembarking throughout the day. We boarded the boat (on the wrong side of the canal, but it all worked out) and crossed to the other side of the channel, where we picked up an Asian family. From there, we floated past windmill after windmill. I was in heaven. We spent the rest of the time trying to avoid the masses of tourists [fairly successfully].

It looked like people live in these windmills, which seemed sketchy in terms of the imminent floods, but I suppose they are tall enough that if they lived on the top story they might be able to survive. I told Nena she should move into a windmill if she stays for a PhD, and just kayak to her neighbor windmill friends' houses. She said she would.

I was so excited that I took over a hundred photos (while Nena rolled her eyes). It was really hard for me to choose which ones to include, but here are a few that are representative of the day:

Panorama of Nena walking along the levee path

Left: classic Holland (I can call it Holland because we are in the Zuid Holland province).  Right: interesting windmill that looks slightly different from the rest.

Left: Nena in a giant wooden dutch shoe wheelbarrow, obviously. Right: Our picnic spot. We ate at 10:45am. Thus began our massive binge that is continuing to this day. 

After our long journey back, we made some delicious mac’n’cheese with arugula and pepper – which we (or at least I) had been craving the whole time. We rested for 20 minutes before departing for TU Delft to get Nena's ID card and have another appointment about insurance. It was pouring outside, so we geared up, and arrived completely drenched. [It's like raincoats are designed to drain onto your jeans and soak them instantaneously.] I waited on the couch for Nena to finish her appointment, and promptly fell asleep after reading a few pages about the dos and don’ts of networking. Nena woke me up so we could trudge back to her apartment. This time we were not only deluged, but we had a close encounter with nearby lightning that was immediately followed by a load explosion of thunder. That quickened our pace, but somehow we made it back without getting struck.

We were supposed to go get pictures of ourselves dressed up as the Vermeer girl and as other traditional Dutch characters, but lost the motivation due to the rain and our exhausting, damp day. Plus, we had already done such a good job of dressing Nena up last night, that it no longer seemed worth the €15. So instead we stayed in an “worked”, meaning that Nena worked while I perused the internet, checked my facebook, chatted with Elizabeth, and generally did what I do best: procrastinate.

"Wringing" the New Year with the King Tides

[This post has been in draft form for 1.5 months, so I figured it was time to accept its imperfections and wrap it up. Lindsey, my fellow king-tide tour-guide also wrote a post, available here]

Choose inundation over inebriation** and celebrate King Tides because it's much more exciting than celebrating the New Year. Why? [Thanks to Lindsey for helping brainstorm this list]

1. The party don't stop: They happen for 3 days, so you can "Cheers!" and wish everyone a HAPPY KING TIDE at least 3 times. And since they happen in different places at different times, you can chase the tide and have that exciting moment multiple times in a day.
2. The party don't stop #2: Another good reason to drink at the Embarcadero 
3. Play; Splashing in puddles an getting hit by waves in normally dry places.
4. Excitement: Fleeing men in golf carts
5. See the future: See what the world will look like every day with sea level rise. 
6. And, because this is a kayaking blog... Expanded kayaking territory. As the water rises, it moves into nearby low-lying areas that are not normally wet, creating new spaces for kayakers to explore. 

** A wonderful expression coined by James Jackson

What are King Tides?
King Tides are the most extreme astronomical* tides that occur every year. A couple times per year, the earth, moon, and sun align in a way that creates the largest tide range. These days it's common for people to compare King Tides to sea level rise. The high tides that we see during the 2013 King Tides will likely happen on a daily basis in ~50 years (and the future King Tides would be even higher!). This year I decided to visit the coast during the King Tides so I could get a sense of what sea level rise might look like (on a good day, without storms).

* Sometimes non-astronomical forces, like weather/waves/storm, can raise tide levels for short periods of time. These changes are less predictable, while King Tides are regular and predictable.

Lindsey, Doug, James, and Barry were my tide-buddies for this year's celebration.

King Tides at the San Francisco Embarcadero (12/31/2013)
On the morning of New Years Eve Lindsey and I snuck out of the office and walked a half mile to the Embarcadero waterfront in San Francisco. The king tide was scheduled for 9:48 am (a 7.07 foot tide). We went to Pier 14, between the Ferry Building and the Bay Bridge, where the King Tides have flooded the Embarcadero in the past. Here are some photos:

Stairwell flooded, and waves breaking onto the sidewalk.

A video of waves lapping over the Embarcadero:

We (Lindsey, Barry, and I) also returned later at the very lowest tide of the day (during King Tides, the lowest tides get very low, so it's a great time to go tide-pooling!). We ran into one of Barry's friends who promptly offered me and Lindsey a ride on his bike-taxi to the Embarcadero. We celebrated the low tide with a six pack of beers, and cheers-ed! at 4:42 pm, when the tide hit -1.35 feet. Here's one of many low-high comparison photos we took:

Extreme low tide:

Extreme high tide:

And the view of San Francisco at sunset wasn't so bad either:

King Tides at Beach Boulevard in Pacifica, CA (1/1/2014)
The next day, Lindsey and I picked up James and Doug for our first King Tide tour of 2014. Our first stop was Beach Boulevard, CA. We also decided to form a band called the King Tide Kids. Cover album:

The crew: James, Doug, Lindsey, and Nena

No beach at high tide, with waves crashing on the massive revetment

We watched a group of kids standing at the edge of the railing daring each other to stay when big waves crashed over the seawall. 

Big waves rolling under the Beach Boulevard Pier

King Tides in Redwood City (1/1/2014)

Our final stops were in Redwood City, where we discovered a dock completely bent out of shape by the extreme high tide:

We (ok, I) decided to jump this fence to get a better view of the Bay at the end of the levee. Minutes later a small golf cart came bumbling along, catching up with us when we finally reached the view point. Two very angry men questioned us: "What was going through your mind when you walked past the 'No Trespassing' sign?" Thankfully Lindsey and Doug fielded the questions while I carefully avoided eye contact.

To learn more, and see much more dramatic photos, check out the California King Tides Initiative!