We didn’t see them on the job yet when we took that photo earlier this afternoon, but crews are expected back at Myrtle Reservoir (map) this week to resume pressure-washing to remove the leaky waterproofing “membrane” material (a problem first reported in this in-depth WSB report three weeks ago). A new update from Seattle Public Utilities says this will be done by Wednesday. The update also says the membrane removal is complete at Beacon Hill Reservoir, the other site with the leaky-waterproofing problem, and that the contractor will start “installing the new waterproofing system on the east half of the reservoir”; that work will be followed, according to SPU, by the waterproofing of Myrtle – which is much smaller than Beacon – and then the west half of Beacon. As SPU told us last month, the waterproofing they’ll use is a “hot asphalt” process. Once it’s done, it’ll be tested, then drain pipe and drain rock will be replaced, followed by topsoil and hydroseeding. SPU adds:

During the course of this work, either Myrtle or Beacon Reservoir may be taken out of service. Water service will not be impacted. Until the work is completed, the two reservoirs will remain fenced off.

The work is expected to be completed at the end of November. Myrtle Reservoir and the area over the Beacon Reservoir will be ready to be turned over to the Parks Department at that time. Construction of the Jefferson Park Expansion Project by Parks Department has already begun on the north end of the Beacon site.

As reported here July 24, the waterproofing re-do is expected to cost more than $4 million; the city has said it expects that ratepayers ultimately will not pick up the tab – though it hasn’t yet been determined who’s to blame for the leaks – and also has pointed out that the $150 million reservoir-covering program citywide is overall $15 million under budget. Meantime, the design for the future Myrtle Reservoir park can be seen here.