Regional Stormwater Facility: Who Pays for It?

For some background on the Town Center Regional Stormwater Facility, read our previous post here. If you've been anywhere near the Civic Center site or the library in the past several months you have likely noticed the construction project going on. The Town Center Regional Stormwater Facility is what is currently being built under the library parking lot. It treats and infiltrates stormwater runoff from about 13 acres in the Town Center.

On our previous post about the project there was some good discussion about how the project was paid for. In short, the City collects stormwater fees from every property owner as part of utility bills. These fees go into a fund that pays for the maintenance, operation, and construction of stormwater facilities in the city. The regional facility was paid for out of these funds.

What is now being proposed by the City is to have the construction costs of the facility shared by developers who would like to take advantage of facility by reducing or eliminating their on-site stormwater requirements.

How this will work is a developer will pay a pro-rated fee contributing to the construction costs of the regional facility based on the amount of area being developed. The total area that will drain to the facility is approximately 13.1 acres and the construction cost of the facility is expected to be around $1.1 million. Divide the cost by the area and you get about $85k per acre. A developer will pay the city this fee in exchange for not having to construct their own stormwater facilities to treat and detain stormwater runoff. Assuming that a developer would have to construct a concrete vault, by my estimate a developer would save roughly half the amount they would typically spend constructing an on-site stormwater facility.

This really is a win-win for everyone involved. The city now has a stormwater facility to treat and detain runoff from their own property (streets and Civic Center), and private developers have a way to decrease some of their costs. Additionally, private land that would have been used for stormwater facilities now has an economic benefit to the city and the developer. A developer would now have more flexibility to use that space to include a couple more units which, in turn, would likely increase the property value and bring in more tax revenue to the city. There's also the ecological benefit of treating and infiltrating runoff from many of the private properties as soon as the project is completed rather than waiting for each property to be developed.


Updated with image below to show discharge point:



How Walkable is Mountlake Terrace?

20 Story Building in My Back Yard?