WEATHER: What else the record-setting rain is doing

As you’ve probably heard, the rainfall this past day-plus is record-setting, 3+ inches. Besides ponding on roads and sidewalks, and turning the ground spongy, there’s one other effect of note: Waterway pollution. The framegrab is from this online map that tracks whether county and city outfalls are experiencing “combined-sewer overflows” – and the ones marked in red were doing just that when we checked just after the top of the hour, including outfalls south of the Fauntleroy ferry dock, along Harbor Island, and on the Duwamish River. The combined-sewer system refers to rainwater draining into the sewer system at such a volume that it overwhelms the system’s capacity. Both the city and county have built projects in recent years – like the Murray Wet Weather Facility across from Lowman Beach Park – to try to reduce the frequency and amount of overflows, but some still happen. In addition to facilities like the one at Lowman that store water until it can be released into the system without an overflow, other projects have sought to relieve the burden on the system by other means such as raingardens and retention ponds.

P.S. Though you can’t stop the rain, you can lessen the effect of stormwater pollution – both CSO-related and the kind that drains directly to local waterways – by following advice like this.

Bradley December 20, 2019 (2:02 pm)

As more and more permeable land with vegetation in West Seattle gets paved-over for denser and denser housing, the storm drain runoff volume has greatly increased in volume and contaminates. Concrete, asphalt, and rooftops are poor substitutes for dirt, grass, and trees.

AMD December 20, 2019 (2:39 pm)

The loss of grass in the city is MORE than offset by the green space that’s saved outside of the city by increasing density in already populated areas versus sprawling into the suburbs. The increased storm volume PALES in comparison to the environmental impact of sprawl, and is a terrible argument against development.
- Bradley December 20, 2019 (6:45 pm)
  
  Too much green space outside of Seattle ISN’T being left pristine: it’s also being developed and densified. The Sammamish Plateau neighborhoods with 1/4-acre, heavily-wooded lots are able to efficiently absorb today’s record rains far better than high-density Kirkland neighborhoods. Urban Seattle is the storm drain runoff capital of Washington: there’s very little permeable ground left for the water to go. That’s why our greenbelts, Lincoln Park, Discovery Park, golf courses, and other open spaces are absolutely vital. Here in Arbor Heights our lower-density and heavy tree canopy are absorbing this deluge of rain well. Over where our rental property is in a high area near South Delridge we’ve been unclogging storm drains all day with city personnel.
  - KM December 20, 2019 (8:43 pm)
    
    Bradley, if you are concerned about what isn’t being left pristine in the city, and suburbs, the solution is more, vertical density (or fewer people). Our spread out, big single family homes that house few instead of many have caused many of the problems we are facing now. A single family home doesn’t imply permeable solutions for water or a tree cover. Large surface areas of roofs and driveways house and support fewer people that an apartment building or townhome cluster. Our neighbor has paved 3/4 of his lot and it’s pretty awful, but he has room for his 4 cars I guess. Because density solves a lot of the per capita permeable surface issue, your first point doesn’t stand. If you are concerned about paved over surfaces though, your issue is with car storage infrastructure (aka parking/driveways) and not density. And I see a heck of a lot of parking in single family neighborhoods.
density saves lives December 20, 2019 (2:58 pm)

Unless you are speaking about the problems of population growth in general, cities are the best place for people, both environmentally and economically.

Sure, “concrete, asphalt, and rooftops are poor substitutes for dirt, grass, and trees.” This is 100% true.

Which is why dense urban centers are the best possible place for people, and why Seattle and other cities should continue to add housing and people and infrastructure.

Leave the country for the countryside, have cities welcome people with open arms by building up and dense and in, and kill the suburbs as much as we can.

So yes, Brad. Good point!
John December 20, 2019 (5:30 pm)

Everyone here is responding to BRADLEY as if his claim had credence. It does not. Their is no truth to the claim that these run-offs are caused by new development impacts. It is the new developments that segregate and infiltrate storm water by code. It is old housing like my 1950’s era home in Gatewood that continues to cause the problems. As correctly reported by WSB, “to try to reduce the frequency and amount of overflows, but some still happen.” The runoffs that the Feds are forcing us to control and contain existed for decades before the current housing boom.
- heartless December 20, 2019 (6:21 pm)
  
  No, basically nobody is taking Bradley seriously. And for good reason.
  
  Nonetheless, one can respond to him kindly and push, sometimes even gently, in the direction of reason.
  
  But yes, John, you are of course correct. Not that that matters much.
  
  Peace.
  - sam-c December 20, 2019 (8:06 pm)
    
    There are (QUITE ENOUGH) regulations on hard surface requirements for new construction. More than enough, thank you very much SPU and SDCI. but regardless, or irregardless, development far outpaces SPU’s understanding of our storm system…… City of Seattle would like everyone to also bow down to developers. They and the CSOs are both overwhelmed, I believe. Good Job SPU !!! Go developers !!

Mark Tiedemann December 20, 2019 (2:27 pm)

Longfellow creek near Dragonfly Pavilion

lowmanbeachdrive December 20, 2019 (9:39 pm)

Thank you for this post; was wondering about Longfellow Creek today. How are things further down by the beaver dam? Creek gets pretty close to houses nearby there.
- WSB December 20, 2019 (9:50 pm)
  
  We went to check on Longfellow at the Yancy end around 6 pm and no flooding there …12 years since this:
  https://westseattleblog.com/2007/12/more-photos-of-delridge-flooding/
  - lowmanbeachdrive December 22, 2019 (11:15 am)
    
    Thank you!

wscommuter December 20, 2019 (3:16 pm)

Folks coming south on Alaskan Way through the merge with SR99 south should be aware of significant flooding right in the merge zone – both lanes underwater and the right lane at least 12 inches deep.

anonyme December 20, 2019 (3:29 pm)

The point is not whether density is better than sprawl, it is whether or not the systems we have set up within the city can adequately handle the additional runoff. They can’t. Green space outside the city does absolutely nothing to offset overflows within it. We need more intelligent planning to cope with the density, including preserving patches of green space, permeable paving, etc. Our city planners are not keeping up, and it’s shameful that there is such a lack of preparedness for such predictable events.

heartless December 20, 2019 (6:18 pm)

Agreed, and obviously the solution to this issue is more taxes–Washington has the worst tax system in the US, and those of us who now realize this are pushing for paying our fair share. Free ride no longer, we need more taxes–as Anonyme and others have pointed out, much of our systems we have set up within the city are failing–and can no longer handle the runoff. We need to invest in our cities, and raise them to the standards we know they can reach.
- Wseattlite December 20, 2019 (11:12 pm)
  
  Heartless, I have very good news for you. You can just give the City more of your money even without more taxes!! You need not be forced to hand over your belongings to this group whom you apparently see as experts with fiscal responsibility and common sense such that you want to give them more than you do. You can simply do so free of will! Some of the rest of us see that as a huge waste of resources that will be lost in beaurictric nonsense, but if you see differently, go ahead! i won’t stop you. Perhaps your contribution will fill the gap between actual funding and some mysterious amount that will finally solve all the problems Yes, utopian ideal the City needs no more money – said this Ciry never and never will Fertilize a weed and it continues to grow
Bradley December 20, 2019 (8:06 pm)

Amen. I’ve owned a rental building since the mid-90s and when we had the all-time-highest rainfall of 5 inches in 24 hours 16 years ago, we had few drainage issues around this block. Today, there are several new multi-family buildings close by on land that single-family homes once occupied. We are now having severe drainage problems with 2 inches LESS rain. The existing drainage was never upgraded to absorb this increased, urban-level density.
- John December 20, 2019 (8:31 pm)
  
  Anecdotal at best, BRADLEYCare to share the location of this claim?
  - Bradley December 20, 2019 (10:40 pm)
    
    I will not (for the security of our tenants) share the exact location of my building, but it is in the South Delridge area and has existed for many decades. It is now surrounded by newer, multi-family units….and far less vegetation….than 25 years ago.
    - John December 21, 2019 (9:21 am)
      
      “I will not (for the security of our tenants) share the exact location of my building.”Of course naming the street and the block like WSB does would somehow risk the security of any tenants. Specious excuse, as we are talking about development and public roads.I would ask BRADLEY how his old building is dealing with its hard surface runoff?
    - Bradley December 21, 2019 (2:11 pm)
      
      My multi-unit building was built in 1968. It was constructed on a slab and is two-story, so no issues with the structure. There are homes with basements nearby with lots of water intrusion last night and this morning. None of these neighboring basements had flooding in the 5.1″ record rainfall of October 2003. Like I mentioned earlier, the surrounding block has FAR less permeable ground than it did 16 years ago and no existing infrastructure upgrades besides LED street lights.

Janelle December 20, 2019 (3:56 pm)

Another thing I would think could be helpful with the heavy rains and water pollution… picking up trash along the sides of the road and near drains. I’m going to try to pitch in and do this in my neighborhood.

Friend O'Dinghus December 20, 2019 (4:34 pm)

Thanks for that photo Mark. That’s impressive flow, and makes me wonder about our little Longfellow Creek before modern times. It must have been able to periodically handle huge volumes of water throughout the eons. Much less channeled than now, but I suspect the volume of water over a long scale may be more similar than dissimilar with volumes of the ancient past. Anyone know about such things? Thanks again Mark for the peek at the extraordinary.

Mj December 20, 2019 (5:20 pm)

Mark – Thank you for the photo. A creek turned into a torrent!

KayK December 20, 2019 (6:04 pm)

I’ve noticed lots of extra runoff and mud in the areas the crows have been thatching for the grubs!

Mj December 20, 2019 (10:27 pm)

Heartless we do not need more taxes! What is needed is redirecting existing taxes to fix infrastructure, a basic government function!

Joe Z December 21, 2019 (10:17 am)

All things considered the impacts seem pretty low for 5 inches of rain. That is partially because of all of the effort put into rain gardens, steep slope mitigation, etc. And SPU is spending a ton of money on a new tunnel to reduce stormwater overflows. I believe they are using one of the old light rail tunnel borers to build it. One of the biggest offenders is old buildings that still have their gutters connected to the sewer system.

John December 21, 2019 (10:58 am)

Right you are JOE Z.The costly mitigation efforts and new codes that reduce run-off from new construction can only do so much with the enormous number of existing homes hard-lined to the combined storm drain sewer is the big culprit. Our 1950’s era home is one of them. Some old homes like ours are in ECA designated areas that the city does not allow rain gardens and infiltration.
- KM December 21, 2019 (12:18 pm)
  
  What is an ECA area, and why doesn’t it allow for rain gardens? Assuming it’s separate than the guidelines the county uses to establish Rainwise areas? We participated in the Rainwise area and it’s been great—I know not all areas qualify for the rebates, but interesting that some areas disallow it all together.

Sorry, comment time is over.