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Westfield Village Phase 6
Engineering Review Comment Response
The following is a reply to the engineering review of the construction plans for phase 6 of
the Westfield Village Subdivision dated August 14, 2003.
1. All public utility construction must be in a dedicated PUE. The PUE must be
submitted to the City prior to plan approval.
A PUE for all utilities not in the ROW is being prepared and will be submitted
to the City. c
2. Sheet 2: Sidewalk required with street. Extend to end of street construction.
The sidewalk is being extended to the end of the boundary of Phase 6 as
required. The additional portion of Victoria is being constructed as a
temporary turn - around as required by the city. A street is currently being
planned to intersect Victoria at Station 49 +78.81 in conjunction with a future
section of Edelweiss Gartens. We have left the sidewalk off intentionally to
avoid its removal when this street is built.
3. Sheet 3: Remove "Typical 40' Subgrade Section"
There are no prohibitions for this type of work in the city regulations and we
believe the diagram is necessary on this project. The soil being excavated
from Mountain Breeze Way is being used as fill on other portions of the
subdivision. This diagram is the only information the contractor will have for
the earthwork along Mountain Breeze Way.
4. Sheet 3: Section A -A should show 7" flex base. Sidewalk is required with
street construction.
Since a turn - around is being required on Victoria, we have attempted to
design a facility that will serve that purpose, but can still be used with the
future extension of Victoria Avenue. Our concern is that any turning
movements by heavy vehicles will damage the surface course and it will
become necessary to replace the asphalt before the city will accept it in the
future. We have designed the temporary turn - around with 5.5 " of base and
1.5" of HMAC. As you can see in the detail, the asphalt is being left 1.5 "
below the lip of the gutter. An additional 1.5" of HMAC will be added to this
portion of the street with future construction of Mountain Breeze Way. We
believe 3" of HMAC on 5.5" of base is a superior section to 7" of base and
1.5" of HMAC.
The sidewalk is addressed in #2 above.
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5. Sheet 4: Curved storm sewer along Night Rain Drive not in accordance with
Drainage Policy and Design Standards (DPDS).
The use of curved storm sewers was approved by the Director of Public Works
for Phase 1 of this subdivision so long as the joint deflections fall within the
manufacturer's guidelines. We are unaware of a change in this policy.
6. Sheet 5: Outlets for Storm Drain A and B. Riprap in channel as shown
constitutes modification to natural watercourse. When placing riprap in lieu
of energy dissipation structure, you must show that velocities are reduced
before entering natural channel.
To our knowledge, there is no prohibition to the modification of an ephemeral
stream through the placement of rip -rap. We are simply installing an outfall
from a development into a natural watercourse (Lick Creek Tributary A) as
done on many other public and private projects. The rip -rap is intended to
provide a short section of lined channel where the velocity in the pipe slows to
the velocity in the receiving stream. Energy dissipation occurs in the swirls
and eddies that form at that point. If the streambed is not lined in this area, it
is subject to washouts immediately below the pipe headwall. Rip -rap has
proven to effectively reduce these washouts on previous projects. It has been
accepted by all of the area governments, including College Station, and it is
unclear why this application is any different than those previous installations.
Formal studies of Lick Creek Tributary A were conducted in the drainage
reports from Alexandria Subdivision and Westfield Subdivision. Those
reports included computer models of the stream in the area where this outfall
is being proposed. The maximum water velocity for both the 100-yr and 25-yr
storm events is 3 fps, which is less than the maximum allowable for grass -
lined waterways in the College Station DPDS. Any runoff coming from
outfalls like the one being proposed will immediately slow to the velocity in
the natural watercourse. With the exception of some eddies in the stream,
there are no erosive velocities to consider. Energy dissipaters at the base of
the outfall will be completely ineffective because they will be submerged by
water in the stream.
In our opinion, this is not an appropriate application of energy dissipation
devices as described in the College Station DPDS. The water velocity in the
receiving stream will not be significantly changed by such devices if installed
at this location.
7. Sheet 6: Manhole required at end of S -2 per TNRCC 317.
The plans have been changed to show this revision.
8. Remove references to "existing" sewer where sewer does not exist.
The plans have been changed to show this revision.
9. Sheet 7: Inset B. Cross not permitted as shown. Install additional valve or
replace cross with tee.
The cross is designed correctly with valves on three of the four legs. As
indicated previously, a street is being planned at the Victoria/Mountain
Breeze Way associated with a future phase of Edelweiss Gartens. The water
line extension shown here is intended to serve that future development.
10. 2" sand cushion required on sidewalk/pathway detail.
The plans have been changed to show this revision.
Westfield Village Subdivision Phase 6
Engineer's Estimate
July 24, 2003
Item Estimated
Description Unit Quantity Total
No. Unit Price
Paving Construction
1 Mobilization Lump Sum 1 10,000.00 10,000
2 Clearing and Grubbing Acre 8.3 1,000.00 8,300
3 Excavation C.Y. 2,546 3.75 9,548
4 1.5" HMAC Surface Course S.Y. 7,672 3.80 29,154
5 6" Lime Stabilized Subgrade S.Y. 9,701 3.00 29,103
6 Extra Lime Ton 60 85.00 5,100
7 7" Crushed Limestone Base S.Y. 3,837 6.75 25,900
8 6" Crushed Limestone Base S.Y. 3,467 5.80 20,109
9 5.5" Crushed Limestone Base S.Y. 368 5.50 2,024
10 Curb and Gutter, all types L.F. 3,752 7.50 28,140
11 Concrete Apron S.Y. 663 35.00 23,205
12 4" Sidewalk S.F. 18,493 2.60 48,082
13 Sidewalk Ramps S.F. 546 9.00 4,914
Paving Subtotal 243,577
Drainage System Construction
14 18" Reinf. Concrete Pipe, Str. Backfill L.F. 190 35.00 6,650
15 21" Reinf. Concrete Pipe, Str. Backfill L.F. 449 37.00 16,613
16 24" Reinf. Concrete Pipe, Str. Backfill L.F. 241 42.00 10,122
17 27" Reinf. Concrete Pipe, Non -Str. Backfill L.F. 127 43.00 5,461
18 30" Reinf. Concrete Pipe, Str. Backfill L.F. 420 48.00 20,160
19 33" Reinf. Concrete Pipe, Str. Backfill L.F. 30 55.00 1,650
20 33" Reinf. Concrete Pipe, Non -Str. Backfill L.F. 37 52.00 1,924
21 10' Curb inlet EACH 4 2,900.00 11,600
22 5' Curb inlet EACH 5 2,200.00 11,000
23 Sloped Headwall for 33" RCP EACH 1 1,000.00 1,000
24 Sloped Headwall for 27" RCP EACH 1 950.00 950
25 Plug for 18" RCP EACH 1 75.00 75
26 Inlet Protection EACH 9 35.00 315
27 Silt Fence L.F. 1,080 2.00 2,160
28 Construction Exit S.Y. 67 5.00 335
29 Dry Rip Rap S.F. 206 5.00 1,030
30 Fibermulch Seeding S.Y. 11,000 0.60 6,600
31 Trench Safety (storm sewer) L.F. 1,494 1.00 1,494
Drainage System Subtotal 99,139
Page 1 of 2
Westfield Village Subdivision Phase 6
Engineer's Estimate
July 24, 2003
Item Estimated
Description Unit Quantity Total
No. Unit Price
Water System Construction
32 6" PVC, C900 Water Line, Str. Backfill L.F. 151 20.00 3,020
33 6" PVC, C900 Water Line, Non -Str. Backfill L.F. 257 14.00 3,598
34 8" PVC, C900 Water Line, Str. Backfill L.F. 1,840 23.00 42,320
35 12" PVC C900 Water Line, Str. Backfill L.F. 785 30.00 23,550
36 Fire Hydrant Assembly EACH 2 2,200.00 4,400
37 6" Gate Valve EACH 1 450.00 450
38 8" Gate Valve EACH 5 650.00 3,250
39 12" Gate Valve EACH 4 1,100.00 4,400
40 2" Blow -Off Assembly EACH 5 525.00 2,625
41 6 "x 11.25 degree Bend EACH 4 175.00 700
42 6" x 13" Anchor Coupling EACH 2 100.00 200
43 8 "x 60" Anchor Coupling EACH 4 200.00 800
44 8 "x 13" Anchor Coupling EACH 1 160.00 160
45 8 "x 8" Tee EACH 1 250.00 250
46 8" x 6" Tee EACH 1 230.00 230
47 8 "x 1" Tapped Tee EACH 1 150.00 150
48 12 "x 8" Cross EACH 2 600.00 1,200
49 12 "x 60" Anchor Coupling EACH 2 400.00 800
50 12 "x 13" Anchor Coupling EACH 2 300.00 600
51 1.5" Water Ser., (avg. length = ft.) EACH 15 750.00 11,250
52 1" Water Ser., (avg. length = ft.) EACH 2 550.00 1,100
53 Trench Safety (water) L.F. 3,033 1.00 3,033
Water System Construction 108,086
Sewer System Construction
54 6" PVC, D -3034, Str. Backfill L.F. 248 29.00 7,192
55 8" PVC, D -3034, Str. Backfill L.F. 460 31.00 14,260
56 8" PVC, D -2241, Str. Backfill L.F. 20 33.00 660
57 Standard Manhole, 0 -8.00 feet EACH 2 1,850.00 3,700
58 Standard Manhole, 8.01 -10.00 feet EACH 1 2,050.00 2,050
59 4" Sewer Service > 10 ft. EACH 7 1,000.00 7,000
60 Trench Safety (sewer) L.F. 728 2.00 1,456
Sewer System Subtotal 36,318
Total Construction Cost $487,120
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