FEIS - Tahoe Regional Planning Agency

RESPONSE TO COMMENTS ON THE DEIS
B o u l d e r B a y C o m m u n i t y E n h a n c e m e n t P r o g r a m P r o j e c t E I S
The commenter states the opinion that plants/vegetation incorporated with pervious
pavers will not withstand pedestrian or vehicular traffic and recommends the UC
Davis Extension for information on pervious pavers. Pervious pavers are proposed
for walkway and patio area that do not have grades exceeding 5%. Roadway areas
that use pervious pavers are not expected to exceed 5% grades due to existing grades
within the project area. The EIS calculations for stormwater runoff assume a
conservative reduction factor of 50% for pervious pavers and not 100% as stated by
the commenter. This data is included in DEIS Appendix R, TMDL Pollutant Load
Reduction Plan. The comment is noted that sand cannot be used for snow and ice
control on pervious asphalt and concrete. The Project proposes the use of automatic
snow melting strategies throughout the pedestrian circulation and promenade and
roadway interiors (page 4.3-21), however, and does not propose sand application for
typical winter operations. The Project also plans for bi-annual spring maintenance of
the pervious surfaces with a regenerative microfilter sweeper system to maintain
infiltration rates of the pervious pavers. The EIS recognizes that improper
maintenance of facilities is a potential impact to surface water quality in impact
HYDRO-1. The potential impact is reduced through conformance with TRPA
codified regulation (standard practices of the Project for compliance), post-project
stormwater monitoring and mitigation measure HYDRO-1.
Comment 137-f: Comment Summary - What is the cost of owning and maintaining a regenerative air
street sweeper mentioned in the DEIS? Would inclusion street sweeping equipment
and a maintenance schedule be included as conditions of project approval?
Regenerative air street sweeping equipment is proposed for Alternatives C and D.
Boulder Bay will be responsible to the cost of owning and maintaining such
equipment. Alternative street sweeping equipment could be required by TRPA as a
condition of project permitting. Submittal and execution of the Inspection,
Maintenance and Monitoring Plan (SP-10), as based on the selected Alternative, will
be a condition of project permitting.
According to a study conducted by the Center for Urban Water Resources
Management, “the use of permeable pavement systems dramatically reduces surface
runoff volume and attenuates the peak discharge during storm events.” Furthermore,
they go on to conclude that “A significant contribution of permeable pavements is the
ability to reduce effective impervious area, which has a direct connection with
downstream drainage systems. This strategy of hydrologic and hydraulic
disconnectivity can be used to control runoff timing, reduce runoff volume, and
provide water quality benefits.”
According to a 2009 study completed by the University of New Hampshire entitled
Seasonal Performance Variations for Storm-Water Management Systems in Cold
Climate Conditions, the pervious pavement and bioretention systems show minimal
to no degradation in either peak flow or removal efficiency performance during cold
winter months.
Comment 137-g: Comment Summary - The DEIS does not mention potential disadvantages of green
roofs (careful design and construction) and lacks critical evaluation. Will
construction of green roofs be a condition of Alternative C approval?
Green roofs are proposed for Alternatives C and D. The costs for construction and
upkeep of green roofs have been incorporated into cost estimates. The Project
proponent will assume the responsibility of operating and maintaining the green
roofs. The commenter states that there are potential disadvantages of green roofs
SEPTEMBER 8 , 2010 HAUGE BRUECK ASSOCIATES PAGE 8- 55