Problems with water main project on Gilmore St

Parisi has been doing a good job with the water main project on Gilmore St.  It's a site of special concern, because of steepness and proximity to LakeWingra.   Here's what we liked...

• Construction phasing was good.  They quickly went to work on the steepest part of the hill, then put an initial surface of asphalt on the street to stabilize it.
• They stabilized the surface by the end of every work day--spraying polymer and using a roller to smooth and compact the surface.
• They used gabions--cages filled with rocks--as movable check dams.  These seemed to work well, though some of them apparently broke open when moved.  We haven't seen this elsewhere in Madison and appreciate the innovation.
• Until recently, little sediment escaped from the site.
• While pavement on Gilmore was still present, it was diligently swept by day's end.

We had a few minor bones to pick, though some of these were corrected promptly when we pointed them out...

• Runoff entering the site from above could easily have been deflected, but wasn't.
• Not enough stormwater inlets downstream were protected with filters, but more were added later.
• The streets nearby were sometimes left dirty.

Violation on Cross St.

But over the last weekend with heavy rains, we noticed an important slip-up...

Cross St has a moderately steep hill for one block.  The upper half of the street (including terraces) was left bare over the rainy weekend, with no check dams or other protection at the bottom.  A good deal of sediment washed towards the Lake.

Lots of sediment escaped down Cross St...

...And onto Chapman St (right), where it moved beyond the last inlet filter.  More filters need to be installed along Chapman, on both sides.  Looking uphill on Chapman towards Cross St.

Probably the most sediment was lost from unprotected terraces, on either side of Gilmore St (here), and on Cross St.  From the bottom of Gilmore, sediment flowed SW on Monroe St.

See all the photos here.