The Washington, DC region is great >> and it can be greater.


Where does the water go?

An awful lot of stormwater just fell on the Washington area. DC Water shared this 2011 video about what happens to a raindrop after it falls in a storm until it gets to a river.

Stormwater has to pass through the Combined Sewer Overflow system, which mixes water and sewage. That is, unless and until DC Water digs new tunnels for stormwater (and, unfortunately, has to spend a very large amount of money to do it).

David Alpert is the founder of Greater Greater Washington and its board president. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He now lives with his wife and two children in Dupont Circle. 


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"Very large" as in @ $2.8 Billion.


by Tom Coumaris on Oct 30, 2012 7:26 pm • linkreport

The next part to the story!

by Doug on Oct 30, 2012 8:34 pm • linkreport

More money should be put into speeding up the process for getting clean drinkable water. This is a major problem in this city. It should be number one for funding.

by Sally on Oct 31, 2012 9:00 am • linkreport

If there is no conversation about financing, then the public has not been informed.

by Jazzy on Oct 31, 2012 9:24 am • linkreport

It's so ridiculous that people can't agree on the need for basic infrastructure. We're not even talking Metro expansion, we're talking about a) securing clean drinking water, b) preventing the flooding of homes, and b) preventing sewage from leaking out. How is there any opposition to this at any cost?

Not to mention $2.5B is chump change. It's not like we're trying to build Water Tunnel No. 3. (

by WMATA Rage on Oct 31, 2012 10:01 am • linkreport

Too bad they don't have such a system in Howard county, which has been dumping raw sewage because of lost power.

by Jasper on Oct 31, 2012 10:31 am • linkreport

@WMATA Rage: Not to mention $2.5B is chump change. It's not like we're trying to build Water Tunnel No. 3.

Two points.
(1) NYC has more people to spread the cost, and this cost is further spread out by the extreme, 50-year time frame of the project.
(2) Average DC monthly water bill: $45.15 (FY 2010); $56.67 (FY 2012); $103.08 (FY 2019).

Before 2010 water rates were already increasing fast. I personally find the prospect of >$100/month water bills to be alarming. I am happy that that won't dent YOUR budget.

by goldfish on Oct 31, 2012 10:47 am • linkreport

if an extra $55 a month for water is a killer, than should rents being hundreds of dollars higher than they otherwise would be sufficient reason to override limits on residential development?

by AWalkerInTheCity on Oct 31, 2012 10:56 am • linkreport

@AWitC: Off-topic; moreover, we are done.

by goldfish on Oct 31, 2012 11:10 am • linkreport

if the question is what is chump change, and we are bringing that to a monthly charge, than it seems to me that putting it in context of total monthly housing costs, and how extraordinarly high they are in DC now, is relevant.

by AWalkerInTheCity on Oct 31, 2012 11:29 am • linkreport

Well, seeing as water is a public good, why is this not being directly financed by taxes? And is there no room for federal contributions? I mean, seriously, we're talking about water here. At some point these types of infrastructure improvements are no longer optional but mandatory for cities in the 20th century. Or later.

by WMATA Rage on Oct 31, 2012 11:52 am • linkreport

@WMATA Rage: why is this not being directly financed by taxes

Paying for this via water use is probably the most fair way to allocate costs. This also includes some suburban ratepayers, which are a provided sewage treatment as a part of DC water.

Tax financing will not change anything; one way or the other, the money for this is coming out the DC residents' pockets.

by goldfish on Oct 31, 2012 12:11 pm • linkreport

I have question about DC Water's project. I contacted DC Water few years ago and they couldn't answer (one time they hung up on me). While in older part of DC, we have combined sewer. Areas north of U Street -- they have dual System -- one for sewer and one for run-off water (which I *believe* go to the river -- I'm not 100% sure of this).

DC Water spent million of dollars upgrading our combined sewer in my area -- why can't they change it to Dual System?

Would it be better to have Dual System to handle the rain (and separating the sewer from residences and businesses)? Better ROI in long run?

by Dave on Oct 31, 2012 3:56 pm • linkreport


This page ( has a map of the combined sewer area - it is very large and includes lots of areas north of U St.

In 2011 DC separated some parts of the CSO at a cost of $11 million ( these were small projects spanning a few blocks.

The millions spent to "upgrade" your CSO would have to be spent anyway, the pipes are very old and need to be replaced regardless. So any amount spent to create a separate stormwater system would be in excess of that.

There are two ways to solve the discharge problem: separate the sewers, or create a storage facility. DC has chosen the storage facility because it costs less than separating the entire system, especially in the long term as there is MUCH less infrastructure required for the storage facility than there is for separating the entire system, and the maintenance is easier because it's only in one place.

by MLD on Oct 31, 2012 4:27 pm • linkreport

The CSO tunnels are, of course, required under a consent decree. DC Water was in violation of the Clean Water Act. The agency didn't have a lot of choice - tunnels, separating systems, whatever - they needed to do something, and it was going to be expensive.

by David R. on Oct 31, 2012 4:38 pm • linkreport

The one thing I would add to MLD's reply is that it's not like separated sewers are particularly clean. Storm sewers take whatever is on the streets (oil leakage, litter, etc) and thus washes down the drain and dumps it into the waterways. Sure, there are catch basins and some crude filters, but it's not like that runoff is treated in any way.

by Alex B. on Oct 31, 2012 4:59 pm • linkreport

@David R.

Correct, the discharge problem has to be solved, and I don't think there are any choices beyond separating the stormwater system or storing the combined system water for future treatment. And as Alex B. notes, storing the water and treating it later results in a cleaner product.

by MLD on Oct 31, 2012 5:16 pm • linkreport

Even an extra $55/mo is a huge burden to put on every homeowner and tenant. Especially since water is skyrocketing anyway.

There is much more water pumped into the sewer system than just metered water and curb rain inflow.

The law exempting commercial buildings from having to pay for sewage used above water usage through pumping ground water needs to be repealed. The fee should be based on the amount of sewage usage, not water usage.

Also, DC could soon be in court again having to show why it is allowing further development to worsen the problem until it has the fix finished.

by Tom Coumaris on Oct 31, 2012 8:47 pm • linkreport

@Tom Coumaris; so you are complaining that you are being charged for water, while the real cost is sewer/runoff?

by charlie on Nov 1, 2012 9:55 am • linkreport

charlie- If my neighbor is metered for 100 gallons of water per month lust like me, but my neighbor only uses 90 gallons of sewage per month while I use 1000 because of a sump pump in my basement, it's totally unfair that we get billed the same. Especially since there's no shortage of water but a critical shortage of sewer capacity.

It may be hard to have meters for sewage use in houses, but not in commercial buildings. And even an estimate based on sewer use would be more fair. I'm sure other places meter or estimate sewage and I'm sure commercial owners had a reason to lobby to get themselves exempted.

by Tom Coumaris on Nov 1, 2012 12:28 pm • linkreport

@Tom Coumaris; right, but wasn't that the result of the previous estimation of wastewater usage (square footage) being thrown out by the feds?

by charlie on Nov 1, 2012 12:47 pm • linkreport

Tom, do you have any actual data that says that pumping out underground spaces constitutes a significant portion of the flow through the CSO?

by MLD on Nov 1, 2012 12:50 pm • linkreport

Even if they could meter sewer use, I am not sure if it could be implemented. Charging customers much more based on an accident of topology does not seem fair.

Put another way: I know of a person that owns a house in Chevy Chase. It sits in a creek valley that was covered over and developed decades ago. When it rains the house floods, and the sump runs constantly.

It isn't fair to charge this homeowner for sewage use for runoff that concentrates from the neighboring properties.

by goldfish on Nov 1, 2012 1:01 pm • linkreport

WASA must have a total of how much water is consumed vs. how much water is put into the sewers. They should also know how much flows into street gutter drains. Subtract that from the sewage total and you'd have an idea how much is pumped.

Measuring household pumping may be hard but measuring commercial building pumping is not. But it's prohibited in DC.

And, I'd think it would be one of the best arguments for eliminating the requirement for these vast underground garages.

The fair method where possible is to have people pay for the amount of water they purchase and also pay for the amount of sewage they use. They're not the same.

by Tom Coumaris on Nov 1, 2012 2:51 pm • linkreport

Additional load from from deep basements has nothing to do with CSOs. This isn't a capacity problem. Right from the system's beginning, the modern DC sewers were designed to dump sewage plus runoff into the rivers when heavy rains fell. There wasn't enough capacity, even when the system opened c. 1895, by intention.

Now, it may be more equitable to assess a higher fee for properties that produce larger amounts of wastewater. That's a different question.

by David R. on Nov 1, 2012 2:55 pm • linkreport

It is a capacity problem as it's when the combined system is full after heavy rains that it overflows into the river. Otherwise the water is treated at Blue Plains.

by Tom Coumaris on Nov 1, 2012 6:27 pm • linkreport

and goldfish- I realize that measuring pumping from houses would be hard. But not so for large commercial, especially new construction. And given our runoff problem it's a major factor that should be considered, both by the city's approval process and by the accountants at developers. If excessive pumping can be avoided it should be. If it can't be avoided, it's cost should be borne by the developer, not every tenant and homeowner city wide.

by Tom Coumaris on Nov 1, 2012 7:03 pm • linkreport

RiverSmart here is a nice start -- but Philadelphia decided to entirely forego an $8B deep tunnel in favor of sinking $2B into citywide green infrastructure, like 1,000+ blocks of pervious paving.

by Payton on Nov 1, 2012 8:34 pm • linkreport

There's a few good papers on the early workings of the DC sewer system, written by engineering honors students at UMD, back in the 1930s. Ralph Rector wrote this in 1939:
Gravity intercepting sewers for collecting the dry weather flow of sewage in the combined sewers have been built according to the plan recommended in the 1890 Hering, Gray and Stearns report. These sewers were designed to carry, when flowing full, a maximum rate of flow of 300 gallons per capita per day from the estimated tributary population. At present there are a large number of storm overflows on the combined sewers, many of which function in times of storm.
Interceptor sewers to handle "dry weather flow."

In other words, the sewers were never capable of handling the most severe storms. Never. Deep basements are not the cause. Eliminate every deep basement and the CSOs would still be running. From the first big storm one, and certainly in 1939, the CSOs were dumping water into creeks and rivers.

by David R. on Nov 1, 2012 8:40 pm • linkreport

@Tom Courmaris: Yes sewer use != domestic water use, and I conceded that it is possible to meter sewer use. But you did not address my point.

All groundwater comes from rain, which then becomes runoff, and eventually soaks into the ground. Let us assume that the rain is spread equally over the city (it most assuredly has "hot spots", and is therefore is NOT distributed equally by area). Only certain properties must pump, and the amount they pump is depends on how much it rains. It is not fair to charge customers the extra amount for water that originally did not fall on their property, but because of groundwater hydraulics, ended up in their sump.

Now I predict you are going point out that commercial properties with deep basements must pump that a normal homeowner does not. Nevertheless, much of the water that comes from a commercial property sump originally fell on residential property, and thus, those residents are responsible for it.

by goldfish on Nov 1, 2012 10:46 pm • linkreport

@David R
Correct, the sewers weren't designed to handle heavy storms. I'm not sure what Tom's argument is. We can't do nothing but we should try to quantify impacts of commercial pumping so we can get them to pay for a bigger chunk of it.

I don't think people are going to be very warm to the idea of a $600 yearly increase in water bills.

by MLD on Nov 2, 2012 8:34 am • linkreport

goldfish- What I said is that as concerns new buildings, a decision to build on a site where there is a water problem should involve consideration of the additional pumping that will be required. In the approval process by the city, whether to build an underground structure or how many levels it will be should be influenced by how much additional pumping will be needed. Also if a builder decides to build a huge underground structure fully aware of the problem, it's not good that the decision will be partly based on the fact that the pumping will be done free of sewage charges.

Also, there are alternatives that can be used in many cases for even residential if there is an incentive. Rain barrels, French drains, deeper gravel or other collecting basins. Financial incentive should be a bigger factor in that decision.

We shouldn't have blanket free pumping into sewers as an incentive to make bad decisions.

I emphasize with your friends in Chevy Chase. I've been through the craziness of underground water problems myself and for a homeowner with existing ground water problems there should be consideration. In fact I doubt there's even a monitorable system for the city to know.

But that's totally different from a corporation building on a site with known or easily discoverable ground water problems and the city or the builder factoring in free pumping when deciding to build several below-ground levels of parking.

At least then, it should be in the equation and if they decide to build it, the sewage cost of the pumping should be on the builder.

by Tom Coumaris on Nov 2, 2012 9:10 am • linkreport

@!Tom Courmaris: OK, so you agree that the situation is complicated, and if I understand you correctly, new sewage charges should be applied only to new construction. But I think most of us that have been following your arguments agree that you need data to show how bad of a problem this is. If only a little is pumped, why bother with this?

by goldfish on Nov 2, 2012 9:28 am • linkreport

goldfish- Your friends in Chevy Chase can tell you it's not just a little pumped when dealing with a high ground water level. And there's a reason builders lobbied so heavily 10 years ago to get exempted (and there's some good argument that if the city forces multi-level underground garages the burden of pumping them should be spread).

Just from having dealt with basement apartment pumps I know that buildings going several levels into the same problem have huge problems and that's verified by construction workers and owners I talk to on every new site around here. If you're ever around 14th and U NW check out the incredible pumping system installed at the new site there. I hate to think of what the pumping systems at CityCenter may be like. And the guarantees from architects that the finished buildings will be water tight from ground water passively just seldom are borne out.

I don't think DC Water keeps records or estimates on how much ground water is pumped into the sewers.

by Tom Coumaris on Nov 2, 2012 10:18 am • linkreport

@Tom Courmaris: context. Yes I know there is a lot of water. But how much compared to the immense volumes that is flowing into the storm drains?

by goldfish on Nov 2, 2012 10:52 am • linkreport

goldfish- Not only will I agree that storm drain input caused by imperious surfaces is the major problem but go further and acknowledge that pumping usually occurs a little later after a deluge when the sewers have passed the initial drainage phase.

However, pumping does coincide with flooding when sewage resources are again strained.

The impervious surface problem also has to be dealt with for sure though.

by Tom Coumaris on Nov 3, 2012 11:50 am • linkreport

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