Agenda packet, regular meeting, first session — Aliso Viejo City Council, October 7, 2026 (part 10 of 11)

thoroughly mixed to achieve a near uniform moisture condition and a uniform blend of materials.

All compaction shall be achieved at or above the optimum moisture content, as determined by the applicable laboratory standard. The Contractor will be notified if the fill materials are too wet or too dry to achieve the required compaction standard.

6. When the moisture content of the fill material is below the limit specified by the Geotechnical Engineer, water shall be added and the materials shall be blended until a uniform moisture content, within specified limits, is achieved. When the moisture content of the fill material is above the limits specified by the Geotechnical Engineer, the fill materials shall be aerated by discing, blading, mixed with dryer fill materials, or other satisfactory methods until the moisture content is within the specified limits.

7. Each fill lift shall be compacted to the minimum project standards, in compliance with the testing methods specified by the controlling governmental agency, and in accordance with recommendations of the Geotechnical Engineer.

In the absence of specific recommendations by the Geotechnical Engineer to the contrary, the compaction standard shall be the most recent version of ASTM :D 1557.

8. Where a slope receiving fill exceeds a ratio of five-horizontal to one-vertical, the fill shall be keyed and benched through all unsuitable materials into sound bedrock or firm material, in accordance with the recommendations and approval of the Geotechnical Engineer.

9. Side hill fills shall have a minimum key width of 15 feet into bedrock or firm materials, unless otherwise specified in the soil report and approved by the Geotechnical Engineer in the field.

10. Drainage terraces and subdrainage devices shall be constructed in compliance with the ordinances of the controlling governmental agency and/or with the recommendations ofthe Geotechnical Engineer and Engineering Geologist.

11. The Contractor shall be required to maintain the specified minimum relative compaction out to the finish slope face of fill slopes, buttresses, and stabilization fills as directed by the Geotechnical Engineer and/or the governing agency for the project. This may be achieved by either overbuilding the slope and cutting Al.TA CALIFORNIA GEOTECHNICAL, INC.
1946
Earthwork Specifications
Page4
back to the compacted core; by direct compaction of the slope face with suitable equipment; or by any other procedure which produces the required result.

12. The fill portion of fill-over-cut slopes shall be properly keyed into rock or firm material; and the fill area shall be stripped of all soil or unsuitable materials prior to placing fill.

The design cut portion of the slope should be made first and evaluated for suitability by the Engineering Geologist prior to placement of fill in the keyway above the cut slope.

13. Pad areas in cut or natural ground shall be approved by the Geotechnical Engineer. Finished surfaces of these pads may require scarification and recompaction, or over excavation as determined by the Geotechnical Engineer.

D. CUT SLOPES

1. The Engineering Geologist shall observe all cut slopes and shall be notified by the Contractor when cut slopes are to be started.

2. If, during the course of grading, unforeseen adverse or potentially adverse geologic conditions are encountered, the Engineering Geologist and Soil Engineer shall investigate, analyze and make recommendations to remediate these problems.

3. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the superjacent, prevailing drainage.

4. Unless otherwise specified in specific geotechnical reports, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies.

5. Drainage terraces shall be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the recommendations of the Geotechnical Engineer or Engineering Geologist.

E. GRADING CONTROL

1. Fill placement shall be observed and tested by the Geotechnical Engineer and/or his representative during grading.

Field density tests shall be made by the Geotechnical Engineer and/or his representative to evaluate the compaction and moisture compliance of each fill lift. Density tests shall be conducted at intervals not to exceed two feet of fill ALTA CALIFORNIA GEOTECHNICAL, INC.
1947
Earthwork Specifications
Pages
height. Where sheepsfoot rollers are used, the fill may be disturbed to a depth of several inches. Density determinations shall be taken in the compacted material below the disturbed surface at a depth determined by the Geotechnical Engineer or his representative.

2. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture content is in evidence, that particular layer or portion thereof shall be reworked until the required density and/or moisture content has been attained. Additional fills shall not be placed over an area until the previous lift of fill has been tested and found to meet the density and moisture requirements for the project and the previous lift is approved by the Geotechnical Engineer.

3. When grading activities are interrupted by heavy rains, fill operations shall not be resumed until field observations and tests by the Geotechnical Engineer indicate the moisture content and density of the fill are within the specified limits.

4. During construction, the Contractor shall properly grade all surfaces to maintain good drainage and prevent the ponding of water. The Contractor shall take remedial action to control surface water and to prevent erosion of graded areas until such time as a permanent drainage and erosion devices have been installed.

5. Observation and testing by the Geotechnical Engineer and/or his representative shall be conducted during filling and compacting operations in order that he will be able to state in his opinion that all cut and filled areas are graded in accordance with the approved specifications.

6. Upon the completion of grading activities and after the Geotechnical Engineer and Engineering Geologist have finished their observations of the work, final reports shall be submitted. No further excavation or fill placement shall be undertaken without prior notification of the Geotechnical Engineer and/or Engineering Geologist.

F. FINISHED SLOPES
All finished cut and fill slopes shall be planted and irrigated and/or protected from erosion in accordance with the project specifications, governing agencies, and/or as recommended by a landscape architect.

ALTA CALIFORNIA GEOlECHNJCAL, INC.
1948
ALTA CALIFORNIA GEOTECHNICAL, INC.

APPENDIX F
Grading Details
1949

DETAIL FOR FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON

PRE-EXISTING SURFACE TO BE

RESTORED WITH COMPACTED FILL
. , .
•'
. .
. ·-~- ALLUVIUM ... "
• • ·., .- ·rb'".-REMA1N: • · . • x.
' • • . '_ ,IN' .PLACE ·. - - •. . ' ,. _ _.'-
• ' ·--~--:··. ,
·.- ~

TOE OF SLOPE AS SHOWN

ON GRADING PLAN
~ 7"'\Q.: 7'"'\Q.: 7'<2: 7'~ 7'~ 7'q__: :T'\<?.;: /\~ 7'<2: :T'\<Z: 7'<2: 7'~ 7'<Z: 7'~

PROPOSED FILL SLOPE

EXISTING TOPOGRAPHY

ANTICIPATED ALLUVIAL REMOVAL

DEPTH PER GEOTECHNICAL ENGINEER
FORECUT VARIES; FOR DEEP REMOVALS, /
FORECUT SHOULD BE MADE NO STEEPER APPiovED PROVIDE A 1 :1 MIN. PROJECTION FROM TOE OF SLOPE AS THAN 1 :1, OR AS REQUIRED FOR SAFETY COMPETENT SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL CONSIDERATIONS MATERIAL BOTTOM. SLOPE HEIGHT, SITE CONDITIONS, AND/OR LOCAL

CONDITIONS COULD DICTA TE FLATTER PROJECTIONS
~ h. ALTA CALIFORNIA GEOTECHNICAL, INC . /L'\.._,-'\. VER. 3/12 PA TH, C1\Users\Jlnks\Desktop\Dro. ftlng\GRADING DETAILS\G-1.dwg PLATE G-1
1950

REMOVAL ADJACENT TO EXISTING FILL

PROPOSED FINISH GRADE
_ _\__ --- -- - -

INTERIM GRADE
afe
•TIE-IN

BACKCUT
(EXISITING ENGINEERED

FILL TO REMAIN IN PLACE)
*INITIATE 1 :1 TIE-IN BACKCUT TO

PROPOSED ADDITIONAL

ENGINEERED FILL
:f:EMPORARY.ENGINEERED FILL
· ••.. ••. At:LUV-11.JM
lt~•l:liREMbVE:C)AND REPLACED
.·•• :~cw:~liiit··.·••·· ·••.· ··•. :\VITt{EN~IN'EBfllio FILL)

APPROVED

COMPETENT

MATERIAL

INTERCEPT TOE OF INTERIM BACKCUT
** AS PART OF TIE-IN FOR ADDITIONAL

ENGINEERED FILL
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. ;'-'\_,_'. VER. 3/12 PATH,C•\Users\Jlnks\Desktop\Drnftlng\GRADING DETAILS\G-2.dwg 1951
PLATE G-2

CANYON SUBDRAIN

PRE-EXISTING

TOPOGRAPHY

APPROVED

REMOVAL
BOTTOM

APPROVED COMPETENT

MATERIAL
SEE DETAIL (PLATE G-4)
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. _/L'\_'_" VER. 3/12 PATH:C:\User11\Jlnks\Desklop\Oraftlng\GRADING DETAILS\G-3.dwg PLATE G-3
1952

CANYON SUBDRAIN DETAIL
FILTER
FABRIC
6" MIN.
6" MIN. OVERLAP
/

PERFORATED PIPE SURROUNDED WITH ROCK AND FILTER FABRIC
ROCK: MIN. VOLUME OF 9 CU.FT. PER LINEAR FT. OF 3/4 IN. MAX. ROCK PIPE: 6 IN. ABS OR PVC PIPE WITH A MINIMUM OF 8 PERFORATIONS (1/4-IN. DIA.) PER LINEAL FT. IN BOTTOM HALF OF PIPE
ASTM D2751, SOR 35, OR ASTM D3034 OR ASTM D1527,
SCHD. 40 ASTM D1785, SCHD. 40
FILTER FABRIC: MIRAFI 140 FILTER FABRIC OR APPROVED EQUIVALENT NOTES:

1. FOR CONTINUOUS RUN IN EXCESS OF 500. FT USE 8 IN. DIA. PIPE

2. ENGINEERED FILL PLACED BELOW DRAINS SHALL BE COMPACTED TO 93% OF THE LABORATORY MAXIMUM DRY DENSITY (ASTM:D1557) .~ ALTA CALIFORNIA GEOTECHNICAL, INC . /L\__'_'\ VER. 3/12 PATH:C:\Users\Jlnks\Desktop\Draftlng\GRADING DETAILS\G-4.dwg PLATE G-4
1953
5' MIN.

OVEREXCAVATION CUT LOT

OVEREXCAVATE AND REPLACE

WITH ENGINEERED FILL

APPROVED COMPETENT MATERIAL

CUT -FILL LOT (TRANSITION)

EXISTING

TOPOGRAPHY

EXISTING

TOPOGRAPHY
MIN.
t
• MIN.
t

OVEREXCAVATE AND RECOMPACT

APPROVED COMPETENT MATERIAL

UNSUITABLE MATERIAL TO BE

REMOVED AND REPLACED WITH

ENGINEERED FILL
•NOTE ALL BUILDING PADS SHALL BE OVER EXCAVATED TO A
MINIMUM OF½ OF THE MAXIMUM DEPTH OF FILL BELOW THE
BUILDING PAD TO A MAXIMUM OF 17 FEET (SEE PLATE G-16)
•~ ALTA CALIFORNIA GEOTECHNICAL, INC. jL"\_'_"\ VER. 3/12 PATH1 C1\Users\Jlnks\Desktop\Dro.f'tlng\GRADING DETAILS\G-5,dwg PLATE G-5
1954

SIDE HILL SLOPE FILL DETAIL
(NATURAL SLOPES 5:1 OR STEEPER)

TOE OF SLOPE ON
PROVIDE A 1 :1 MINIMUM GRADING PLAN

PROJECTION FROM DESIGN

TOE OF SLOPE TO TOE OF KEY

NATURAL SLOPE TO

BE RESTORED WITH

COMPACTED FILL
.

PROPOSED
GRADE

FORECUT
VARIES
, 3' MIN.
lf::T'"
2' MIN.

INTO APPROVED

COMPETENT

MATERIAL
l--15• MIN.~r,, NOTES:

MIN. KEY DIMENSION 15'X2'X3' FOR
SLOPE HEIGHTS LESS THAN 30 FT.

SLOPES GREATER THAN 30 FT., KEY
WIDTH IS SLOPE HEIGHT DIVIDED BY 2.
• ALTA CALIFORNIA GEOTECHNICAL, INC . /L\-'~\, VER. 1/18 PATH,C•\User-s\Jlnks\Desktop\Dr-nftlng\GRADING DETAILS\G-6,dwg

EXISTING

TOPOGRAPHY
--j

WIDTH VARIES
~MPACTED FILL
/
MAINTAIN MIN. 15' HORIZ. WIDTH

FROM FACE OF SLOPE TO BENCH/BACKCUT
T

1. WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS, SEE PLATE G-1. WHERE THE NATURAL SLOPE APPROACHES OR EXCEEDS

THE DESIGN SLOPE RATIO, SPECIAL RECOMMENDATIONS WILL
BE PROVIDED BY THE GEOTECHNICAL ENGINEER.

2. THE NEED FOR AND PLACEMENT OF DRAINS WILL BE

DETERMINED BY THE GEOTECHNICAL ENGINEER OR
GEOLOGIST BASED UPON EXPOSED FIELD CONDITIONS .

PLATE G-6
1955
*DESIGN CUT SLOPE
. ···,·
.·- ..

0. /

APPROVED COMPETENT

MATERIAL

FILL OVER CUT SLOPE DETAIL

SHORT-TOP

FILL SLOPE

PROPOSED

EXISTING

TOPOGRAPHY
CATCH
POINT
GRADE
--I

WIDTH MAY VARY
15' MIN.

MIN. KEY DIMENSION 15'X2'X3' FOR
SLOPE HEIGHTS LESS THAN 30 FT. SLOPES GREATER THAN 30 FT., KEY WIDTH IS SLOPE HEIGHT DIVIDED BY 2

NEED AND LOCATION OF HEEL DRAIN TO BE

DETERMINED BASED UPON FIELD CONDITIONS,
SEE DETAIL PLATE G-8
•THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND

EVALUATED BY THE ENGINEERING GEOLOGIST/GEOTECHNICAL

ENGINEER PRIOR TO CONSTRUCTING THE FILL SLOPE
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. ;L'\_'_"\ VER. 1/18 PLATE G-7 PATH,C•\Users\Jlnks\Desktop\Droftlng\GRADING DETAILS\G-7 (Toa 10-6-17),dwg 1956

STABILIZATION/BUTTRESS FILL BACKDRAIN
NOTE:

1. ASTM 02751, SOR 35, OR ASTM 03034 OR
ASTM 01527, SCHD. 40ASTM 01785, SCHD. 40

2. SOLID PIPE OUTLETS TO BE PROVIDED EVERY 100 FT.

AND JOINED TO PERFORATED BACKDRAIN PIPE WITH
"L" OR 'T's. MIN. 2% GRADIENT.

FILTER FABRIC
MIN. 6" OVERLAP
ALTERNATIVE NO. 2
2' MIN.
--+!-·•~··~~-"~-•_o~-;,-·. -~----- --~-
PIPE
4" MIN.
.. Ci .'

FINISHED GRADE
2" MIN.

TOE
ALTERNATIVE NO. 1
PIPE
4" MIN.

HEEL
2' MIN.
0 2" MIN.
z

3. GRAVEL TRENCH TO BE FILLED WITH 3/4 IN. MAXIMUM
ROCK

4. THE NECESSITY FOR UPPER TIER BACKDRAINS SHALL BE

DETERMINED IN THE FIELD BY THE GEOTECHNICAL ENGINEER
OR GEOLOGIST. UPPER TIER OUTLETS SHOULD DRAIN INTO
PAVED TERRACE DRAINS.

5. ENGINEERED FILL PLACED BELOW DRAINS SHALL BE COMPACTED TO 93% OF THE LABORATORY MAXIMUM DRY DENSITY (ASTM:01557) TYPICAL 2 FT. X 2 FT. 3/4 IN. MAX. ROCK FILLED TRENCH WITH 4 IN. DIA. ABS OR PVC PIPE OR APPROVED SUBSTITUTE. PROVIDE MINIMUM 8 PERFORATIONS (1/4-IN. DIA.) PER LINEAL FOOT IN BOTTOM HALF OF PIPE. PIPE IS TO EXTEND FULL LENGTH OF BUTTRESS OR STABILIZATION FILL WITH A MINIMUM GRADIENT OF 2% TO OUTLET PIPES.

I .. 15' MIN;. I

OVEREXCAVATION - AS REQUIERD
~-- BY GEOTECHNICAL ENGINEER OR
GEOLOGIST (3' MIN)
~i----- BACKCUT BENCHED AT CONTACT
4" NON- PERFORATED PIPE TO BE PLACED

AT LOTS LINES OR AS DESIGNATED BY THE

GEOTECHNICAL ENGINEER OR GEOLOGIST
2' MIN. KEY DEPTHJ-~--
15' MIN. KEY WIDTH 3' MIN. KEY DEPTH
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. ~"\_'_'\ VER. 3/12 PATH,C•\Users\Jlnks\Desktop\DrQftlng\GRADING DETAILS\G-8,dwg PLATE G-8
1957

EXISTING

TOPOGRAPHY
.h ALTA CALIFORNIA GEOTECHNICAL, INC . ;L'\_'_"\ VER. 1/18

STABILIZATION FILL
(UPSLOPE ALLUVIATED AREA)

CONSTRUCT STABILIZATION FILL
(MINIMUM KEY 15'x2'x3')

PROPOSED
GRADE
T
BENCH

BACK DRAIN
PER DETAIL G-8
* FOR SLOPE HEIGHTS LESS THAN 30 FT.

SLOPES GREATER THAN 30 FT., KEY
WIDTH IS SLOPE HEIGHT DIVIDED BY 2

PROVIDE BERM, PAVED SWALE,

AND/OR STORM DRAIN PER

CIVIL ENGINEER

UPPER DRAIN AT

ALLUVIUM/BEDROCK
CONTACT. PROVIDE OUTLETS BASED UPON

RECOMMENDATIONS OF

GEOTECHNICAL ENGINEER

OR GEOLOGIST
PLATE G-9
1958

SELECTIVE GRADING DETAIL FOR STABILIZATION FILL

UNSTABLE MATERIAL EXPOSED IN PORTION OF CUT SLOPE

EXISTING

TOPOGRAPHY

COMPACTED FILL

THE NEED FOR AND DEPTH OF

OVEREXCAVATION TO BE DETERMINED

BY THE GEOTECHNICAL

ENGINEER/GEOLOGIST

APPROVED COMPETENT

MATERIAL

IF RECOMMENDED BY THE GEOTECHNICAL ENGINEER/GEOLOGIST

THE REMAINING CUT PORTION OF THE SLOPE MAY REQUIRE

REMOVAL AND REPLACEMENT WITH A KEYWAY (W') AND COMPACTED FILL (SEE PLATE G-8)
NOTES: 1. BACKDRAINS ARE NOT REQUIRED UNLESS SPECIFIED.

2. "W" SHALL BE EQUIPMENT WIDTH (15') FOR SLOPE HEIGHT LESS THAN 25 FEET. FOR SLOPES GREATER THAN 25 FEET, "W" SHALL BE DETERMINED BY THE PROJECT GEOTECHNICAL ENGINEER/GEOLOGIST.

AT NO TIME SHALL "W" BE LESS THAN H/2.
-~ ALTA CALIFORNIA GEOTECHNICAL, INC. ~°\_'_'\, VER. 3/12 PATH,C•\Users\Jlnks\Desktop\Droftlng\GRADING DETAILS\G-10,dwg PLATE G-10
1959

SKIN FILL SLOPE OVER NATURAL GROUND
- T --· 2'MIN.

ENGINEERED FILL t
/
/
/

PROPOSED
GRADE
/4
• 0 3' MIN.
t
1--- 15' MIN. -----1

EXISTING

TOPOGRAPHY
15' MIN. TO BE MAINTAINED

FROM SLOPE FACE TO BACKCUT

NEED AND LOCATION OF HEEL DRAINS TO BE
...___ DETERMINED BASED UPON FIELD CONDITIONS
MIN. KEY DIMENSIONS 15'X2'X3' FOR IF REQUIRED, SEE DETAIL PLATE G-8 SLOPE HEIGHTS LESS THAN 30 FT. SLOPES GREATER THAN 30 FT., KEY WIDTH IS SLOPE HEIGHT DIVIDED BY 2
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. /L\.._'_ \, VER. 1/18 PLATE G-11 PATH,C•\Users\Jlnks\Desktop\Draftlng\GRADING DETAILS\G-11.dwg 1960

DETAIL FOR MAXIMUM PARTICLE DIMENSION

PROPOSED
G\ADE
ZONE
1 - - 1
3 ~-" _'::,,__ FILL SLOPE SURFACE
7 ............ __ ,5.~ / ZONE 2 7 FT "-.........._ '--...... ------~------'~ ...... , ...... -..............

ZONE 3 >10 FT ',....._ ZONE 4 ...............

I ',,
PARTICLE MAX.

ZONE DEPTH DIMENSION
1 0-3ft. ~1.0 ft.
2 3-10 ft. ~2.0 ft.
3 >10 ft. ~8.0 ft.
15 HORIZONTAL FEET 4 FROM Fill SLOPE FACE ~1.0 ft.
-~ ALTA CALIFORNIA Gl!DTl!!CHNICAL, INC. ;L"' '-. VER. 2/15 ...... ' '

PLACEMENT METHOD

STANDARD OR CONVENTIONAL

COMPACTION METHODS
(SEE EARTHWORK SPECIFICATIONS)

ROCK BLANKETS
(SEE PLATE G-13)
ROCK BLANKETS (PLATE G-13)
ROCK WINDROW (PLATE G-14)
INDIVIDUAL ROCK BURIED (PLATE G-15)

STANDARD OR CONVENTIONAL

COMPACTION METHODS
(SEE EARTHWoRK SPECIFICATIONS)
PLATE G-12
PATH C1\Users\scott\Dropbox CAl to. CA Geotechnlc:aO\Atto. Server'\ To Jlnks\.Dro. ftlng\GRADlNG DET A!LS\G-12,dwg 1961

ROCK BLANKET DETAILS
LOOSE PILE 1

LOOSE, DUMPED ROCK, GRAVEL ANO SAND MIXTURE REMOVE
FRAGMENTS LARGER THAT 2 FEET FOR ISOLATED BURIAL
(PLATE G-15) OR WINDROW (PLATE G-10)
COMPACT PILE 1
SPREAD LOOSE PILE FORWARD W!TH HEAVY TRACKED DOZER (D-8 OR LARGER). HEAVILY WATER, TRACK, AND APPLY ADDITIONAL SAND

ANO GRAVEL AS NECESSARY TO FILL VOIDS AND CREATE A DENSE MATRIX OF ROCK, COBBLES, GRAVEL AND SAND (2 FOOT MAXIMUM

THICKNESS)
APPROVED BOTTOM, OR TOP Of='.

PAEVIOUSL Y APPROVED BLANKET
Fill

COMPACTED
PILES 1 AND 2

APPROVED BOTTOM, OR TOP OF

PREVIOUSLY APPROVED BLANKET
FILL

APPROVED BOTTOM, OR TOP OF

PREVIOUSLY APPROVED BLANKET
FILL
LOOSE PILE 2

DUMP SUCCESSIVE PILES OF LOOSE ROCK, GRAVEL AND SAND

MIXTURE ON FORWARD EDGE OF PREVIOUSLY COMPACTED LIFT
WITH TRUCKS AND/OR SCRAPERS. USE PREVIOUS LIFT TO ACCESS AND FURTHER COMPACT P1LE 1.

LOOSE PILE 3

DUMP SUCCESSIVE PILES OF LOOSE ROCK, GRAVEL AND SAND

MIXTURE ON FORWARD EDGE OF PREVIOUSLY COMPACTED LIFT
WITH TRUCKS AND/OR SCRAPERS. USE PREVIOUS LIFT TO ACCESS AND FURTHER COMPACT EXISTlNG BLANKET.

OBSERVATION TESTING AND APPROVAL PROCEDURES
OBSERVE EQUIPMENT. SCRAPERS AND TRUCKS SHOULD BE FULLY SUPPORTED ON BLANKET WITHOUT SIGNIFICANT YIELDING.

EXCAVATE TEST/OBSERVATION PITS TO CONFIRM EXISTENCE OF MIXTURE OF VARIOUS PARTICLE SIZES, WITHOUl SIGNIFICANT VOIDS, AND FOAMING A DENSE, COMPACTED FILL MATRIX. TEST BY ASTM D1556, D2922 AND/OR D3017 WHEN APPROPRIATE, RECORD LIMITS AND ELEVATION OF BLANKET. ALL FILL AND COMPACTION OPERATIONS TO BE CONDUCTED UNDER THE OBSERVATION OF THE GEOTECHNICAL ENGINEER. SUBSEQUENT UFTS TO BE APPLIED ONLY AFTER OBSERVATION AND CONFIRMATION OF SUITABILITY OF FILL ANO RELEASE BY THE GEOTECHNICAL ENGINEER. BLANKETS TO BE CONSTRUCTED IN ACCORDANCE WITH PLATE G-12 .
• ~ ALTACALIFORNIAGEOTECHNICAL, INC. /L'\_'_'\ VER. 3/12 PATH:C:\ UHrw\Jlnks\O.sktop\0raflfng\GRADING DETAILS\G-13.dwg PLATE G-13
1962

PROPOSED ROCK WINDROW DETAIL
GR,:_
"" 1 O' *
------------.--"-~__l__
SEE PLATE G-12 PROPOSED SLOPE SURFACE
--....

C> '---.... "- --.... --....

D ~----, 15'---" I-- 1 5' --I ~ --.._ '---.._
WINDROW '-....__
(TYPICAL) '-'
=
t=
a
NOTE: OVERSIZED MATERIAL SHOULD BE REMOVED FROM THE 15'

CLEAR ZONES WITH SPECIAL EQUIPMENT, SUCH AS A
ROCK RAKE, PRIOR TO PLACING THE NEXT FILL LIFT.
*VARIANCES TO THE ABOVE ROCK HOLD DOWN MAY BE GRANTED

SUBJECT TO APPROVAL BY THE OWNER, GEOTECHNICAL ENGINEER,

AND GOVERNING AGENCY

TYPICAL WINDROW DETAIL (END VIEW)

HORIZONTALLY PLACED

COMPACTED FILL

GRANULAR SOIL FLOODED

TO FILL VOIDS
NOTE: COMPACTED FILL SHALL BE BROUGHT UP TO A HIGHER ELEVATION ALONG EACH WINDROW SO GRANULAR SOIL CAN BE FLOODED IN A "TRENCH CONDITION".

PROFILE VIEW
-~ ALTACALIFORNIAGEOTECHNICAL, INC. ~'\_'_"\ VER. 3/12
PATH1C1\Users\Jlnks\Desktop\Dro.ftlng\GRADING DETAILS\G-14,dwg PLATE G-14
1963

ISOLATED ROCK BURIAL DETAILS
"•' ··,.,, . .,.- .
. ;;-~ i:;;;.

EXCAVATE HOLE INTO EXISTING FILL PRISM, PLACE BOULDER(< 8 feet in maximum dimension) INTO EXISTING COMPACTED FILL. SURROUND WITH SAND, GRAVEL, COBBLES AND WATER HEAVILY. TRACK WITH DB OR LARGER EQUIPMENT UNTIL RESULTING FILL FULLY SUPPORTS EQUIPMENT. OBSERVE AND/OR TEST IN ACCORDANCE WITH ASTM D1556, D2922 OR D3017. ROCKS LARGER THAN 8 FEET SHALL BE FURTHER REDUCED IN SIZE BY SECONDARY BREAKING . . ~ ALTA CALIFORNIA GEOTECHNICAL, INC. /L"\-,-, VER. 3/12 PATH:C:\ erw\Jlnka\Deaklop\Drafflng\GRADING DETAILS\ G-15.dwg PLATE G-15
1964
RELATIVE COMPACTION VS. DEPTH

CANYON WALL LAY BACK

DIFFERENTIAL FILL OVEREXCAVATION DETAILS

PROPOSED
GRADE
_ _/
t
50'=90%

BUILDING PAD,---
2:1 LAYBACK OF
CANYON WALL®

EXISTING

TOPOGRAPHY
t
'APPROVED COMPETENT
.~ ALTA CALIFORNIA GEOTECHNICAL, INC. ;'-"\_'_'\ VER. 3/12 PATH1C1\User-s\Jlnks\Desktop\Dro.f'tlng\GRADING DETAILS\G-16,dwg

MATERIAL

1. ALL FILL PLACED BELOW 50 FEET OF FINISHED GRADE SHALL BE COMPACTED TO A MINIMUM OF 93% RELATIVE COMPACTION .
.

2. CANYON WALLS WITHIN 50 FEET OF FINISHED GRADE SHALL BE LAID BACK TO A SLOPE RATIO OF 2:1 OR FLATTER.

3. ALL BUILDING PADS SHALL BE OVER EXCAVATED TO A MINIMUM OF 1 /3 OF THE MAXIMUM DEPTH OF FILL BELOW THE BUILDING PAD TO A MAXIMUM OF 17 FEET.

4. IF THE 2:1 LAY BACK OF THE CANYON WALL IS IMPRACTICAL, THEN AS AN ALTERNATIVE THE INCREASED COMPACTION STANDARDS IN NOTE 1 SHOULD BE EXTENDED UP TO H/3 AND THE LAY BACK WILL NOT BE REQUIRED. PLATE G-16
1965
5'
t

SETTLEMENT PLATE DETAIL
2'X2' X 1/4" STEEL PLATE
STANDARD 3/4" PIPE NIPPLE, WELDED
TOP AND UNDERSIDE OF PLATE.
3/4" DIA. X 5' LONG GALVANIZED PIPE,
flllF-----t---STANDARD PIPE THREADS TOP AND

CAP AND COVER
PER PLATE G-12A
5' 5'
BOTTOM. EXTENSIONS THREADED BOTH
ENDS AND ADDED IN 5' INCREMENTS.
3" DIA. SCHEDULE 40 PVC, ADD IN 5'
INCREMENTS, GLUE JOINTS.

MAINTAIN 5' HORIZONTAL CLEARANCE FOR HEAVY
EQUIPMENT. HAND COMPACT IN 2' VERTICAL

INCREMENTS OR ALTERNATIVE SUITABLE TO
AND ACCEPTED BY THE GEOTECHNICAL ENGINEER.

HAND COMPACT INITIAL 5' (VERTICAL)
WITHIN 10' HORIZONTAL

PLACE AND HAND COMPACT INITIAL
2' OF FILL PRIOR TO ESTABLISHING 2
•
5 '=:::.LX,'•--·',i~~ilti·?i/a:;~;;;:·1=;'j~--~=iii-;:...~~,.........::,,.__ INITIAL READING 'REMOVAL BOTTOM
PROVIDE 1-INCH OF SAND/GRAVEL BEDDING MINIMUM
NOTES:
1) LOCATIONS OF SETTLEMENT PLATES SHALL BE CLEARLY MARKED AND READILY VISIBLE (RED FLAGGED) TO EQUIPMENT OPERATORS.
2) CONTRACTOR SHALL MAINTAIN 10' HORIZONTAL CLEARANCE FOR HEAVY EQUIPMENT WITHIN 5' (VERTICAL) OF PLATE BASE. FILL WITHIN CLEARANCE AREA SHALL BE HAND

COMPACTED TO PROJECT SPECIFICATIONS OR COMPACTED BY ALTERNATIVE APPROVED BY THE GEOTECHNICAL ENGINEER.
3) AFTER 5' (VERTICAL) OF FILL IS IN PLACE, CONTRACTOR SHALL MAINTAIN 5' HORIZONTAL EQUIPMENT CLEARANCE. FILL IN CLEARANCE AREA SHALL BE HAND COMPACTED (OR APPROVED ALTERNATIVE) IN VERTICAL INCREMENTS NOT TO EXCEED 2 FEET. 4) IN THE EVENT OF DAMAGE TO SETTLEMENT PLATE OR EXTENSION RESULTING FROM

EQUIPMENT OPERATING WITHIN PRESCRIBED CLEARANCE AREA, CONTRACTOR SHALL

IMMEDIATELY NOTIFY GEOTECHNICAL ENGINEER AND SHALL BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATE AND EXTENSION RODS TO WORKING ORDER . • ~ ALTA CALIFORNIA GEOTECHNICAL, INC . ,IL'\_'_'\ VER. 3/12 PLATE G-17 PATH1C1\Users\Jlnks\Desktop\Drnf'tlng\GRADING DETAILS\G-17,dwg 1966

SURFACE SETTLEMENT MONUMENT DETAIL
=I I 1==111
CONCRETE OR PLASTIC = I I

SPRINKLER VAULT

PVC CAP
~-11111
... 3'8" LONG #8 REBAR OR_-~'f:!::l:J,-a--, ---:.-
3/4" GALVANIZED PIPE
4" SCH. 40 PVC PIPE
' . . .
. \·
.. .
==11 ••. ' •
L I i1il::
.~ ALTACALIFORNIAGEOTECHNICAL, INC.
~\__'_'\. VER. 3/12
PATH1C1\Users\Jlnks\Desktop\Draftlng\GRADING DETAILS\G-18,clwg 6'
2'
- -I
I
I
--lr..,..,..J.-,-,-,-_-,J-,.1
-111==11

CONCRETE OR SLURRY
. : 3 FEET MIN.

APPROX. 6" EMBEDMENT

INTO COMPACTED FILL
PLATE G-18
1967
0 1.0' MIN BELOW

LOWEST UTILITY
.~ ALTA CALIFORNIA GEOTECHNICAL, INC , /L"\,__'_'\, VER. 3/13 VARIES
VARIES

PER PLAN
PATH,C•\Users\Jlnks\Desktop\Drnftlng\GRADING DETAILS\G-19,dwg R/W

LOT LENGTH (VARIES)
~w
en z
Cl ::J
-o z " g <( 5 CD PAD ELEVATION AS SHOWN ON PLAN
SLO\RIES~----LCD-------=:i:m~~--
3 r,-,;_-171
+ 6'
__ ,____,_1-"'-% MINIMUM

UNDERCUT

VARIABLE UNDERCUT SLOPE & DEPTH

DEPENDING ON UTILITY DEPTH
I

TYPICAL STREET, PARKWAY AND PAD UNDERCUT

NO SCALE
PLATE G-19
1968
Tm P-2 B-4 B-1 B-2 B-3 P-1 170 N. MAPLE STREET, STE 108, CORONA, CA 92880 TELEPHONE: (951) 509-7090
ALTA CALIFORNIA GEOTECHNICAL, INC. PLATE 1 MONTEREY FORMATION APPROXIMATE LOCATION OF HOLLOW STEM AUGER BORING APPROXIMATE LOCATION OF INFILTRATION TEST LIMITS OF REPORT LEGEND P-2TmB-4 EB 0 -

BRANDYWINE
HOMES
\
\
\
\
\
\ \
\
I
\
I

EX TOE or SLOPE
\
I
\ \____ ;
\
\

EX TOE or SLOPE
-------
r-:·" [ l )) t~l [ll
15 Argonaut
<nJ
1,
\::,!/
\
\
\
\
\
lrcF.JVi IIiJilrr1m,1 W1J"'u·1°, cn·,11·
,_
'"'" ~·-'~"'"' uu ~11u nuiulJ.
l raiJ:;;81 ltko ~1
/ ) ,,/
--s.f',\
(-,;,.~-\~ '.~) \
;;:y ?\,-.}:<ii;~~ 1"0-\11\9 \') V I;:::;-,
I
\
C Pltlil i · Ml j :5, 2 :5, i:)J~' j :s
. 0m,1sm {C,;',,Yc•""h
C (i
C
C U C U/;1 o
c If- m: ii 7
fr'") ---. , -- --- ,;-::i -
1<)lp;1ri U-u r;.1~&XG@~
1 0 ) -..·h\•.'' i' ,;-s I 1 ·',_,', ·-: i \ j
[i]! c; e ,•an
C• ~ Ill ,H, ' ·',"•', 1'i:c v-1 ~ ,,s- , -, /C'
- •0 J·0 ,;,; J :\;: \.J.:Ssil
SP-06
minimum
PROJECT NUMBER: 1-0631 DATE:Sept. 2025
t

7. ARCHITECTS . PLANNERS . DESIGNERS
ORANGE COUNTY• LOS ANGELES. BAY AREA
1969
Water Quality Management Plan (WQMP)

Presidio

Attachment F: HYDROMODIFICATION

CALCULATIONS
1970
SOHM

PROJECT REPORT
1971
160715-SOHM 7/8/2026 3:24:33 PM Page 2
General Model Information
Project Name: 160715-SOHM
Site Name: Presidio
Site Address: 15 Argonaut
City: Aliso Viejo
Report Date: 7/8/2026
Gage: Laguna Beach
Data Start: 10/01/1949
Data End: 09/30/2006
Timestep: 15 Minute
Precip Scale: 1.000
Version Date: 2021/05/25
POC Thresholds
Low Flow Threshold for POC1: 10 Percent of the 2 Year
High Flow Threshold for POC1: 10 Year
1972
160715-SOHM 7/8/2026 3:24:33 PM Page 3
Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
A,Scrub,VSteep(>15%) 4.56
Pervious Total 4.56
Impervious Land Use acre
Impervious Total 0
Basin Total 4.56
Element Flows To:

Surface Interflow Groundwater
1973
160715-SOHM 7/8/2026 3:24:33 PM Page 4
Mitigated Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
A,Scrub,Flat(0-5%) 0.43
A,Scrub,VSteep(>15%) 2.04
Pervious Total 2.47
Impervious Land Use acre
Impervious,Flat(0-5) 1.93
Impervious,Mod(5-10) 0.16
Impervious Total 2.09
Basin Total 4.56
Element Flows To:

Surface Interflow Groundwater
StormTech 1 StormTech 1
1974
160715-SOHM 7/8/2026 3:24:33 PM Page 5
Routing Elements
Predeveloped Routing
1975
160715-SOHM 7/8/2026 3:24:33 PM Page 6
Mitigated Routing
StormTech 1
Chamber Model: 3500
Dimensions
Max Row Length: 200
Number of Chambers: 40
Number of Endcaps: 16
Top Stone Depth: 12
Bottom Stone Depth: 9
Discharge Structure
Riser Height: 4.5 ft.

Riser Diameter: 54 in.

Notch Type: Rectangular
Notch Width: 3.839 ft.

Notch Height: 1.093 ft.

Orifice 1 Diameter: 1.916 in. Elevation:0 ft.

Element Flows To:

Outlet 1 Outlet 2
StormTech Hydraulic Table
Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs)

0.0000 0.047 0.000 0.000 0.000

0.0833 0.047 0.001 0.028 0.000

0.1667 0.047 0.003 0.040 0.000

0.2500 0.047 0.004 0.049 0.000

0.3333 0.047 0.006 0.057 0.000

0.4167 0.047 0.008 0.064 0.000

0.5000 0.047 0.009 0.070 0.000

0.5833 0.047 0.011 0.076 0.000

0.6667 0.047 0.012 0.081 0.000

0.7500 0.047 0.014 0.086 0.000

0.8333 0.047 0.017 0.090 0.000

0.9167 0.047 0.021 0.095 0.000

1.0000 0.047 0.025 0.099 0.000

1.0833 0.047 0.028 0.103 0.000

1.1667 0.047 0.032 0.107 0.000

1.2500 0.047 0.035 0.111 0.000

1.3333 0.047 0.038 0.115 0.000

1.4167 0.047 0.042 0.118 0.000

1.5000 0.047 0.045 0.122 0.000

1.5833 0.047 0.049 0.125 0.000

1.6667 0.047 0.052 0.128 0.000

1.7500 0.047 0.056 0.131 0.000

1.8333 0.047 0.059 0.134 0.000

1.9167 0.047 0.062 0.137 0.000

2.0000 0.047 0.066 0.140 0.000

2.0833 0.047 0.069 0.143 0.000

2.1667 0.047 0.072 0.146 0.000

2.2500 0.047 0.076 0.149 0.000

2.3333 0.047 0.079 0.152 0.000

2.4167 0.047 0.082 0.154 0.000

2.5000 0.047 0.085 0.157 0.000

2.5833 0.047 0.088 0.160 0.000

2.6667 0.047 0.091 0.162 0.000
1976
160715-SOHM 7/8/2026 3:24:33 PM Page 7

2.7500 0.047 0.095 0.165 0.000

2.8333 0.047 0.098 0.167 0.000

2.9167 0.047 0.101 0.170 0.000

3.0000 0.047 0.104 0.172 0.000

3.0833 0.047 0.107 0.174 0.000

3.1667 0.047 0.110 0.177 0.000

3.2500 0.047 0.112 0.179 0.000

3.3333 0.047 0.115 0.181 0.000

3.4167 0.047 0.118 0.195 0.000

3.5000 0.047 0.121 0.547 0.000

3.5833 0.047 0.123 1.133 0.000

3.6667 0.047 0.126 1.880 0.000

3.7500 0.047 0.129 2.758 0.000

3.8333 0.047 0.131 3.750 0.000

3.9167 0.047 0.133 4.845 0.000

4.0000 0.047 0.136 6.033 0.000

4.0833 0.047 0.138 7.308 0.000

4.1667 0.047 0.140 8.663 0.000

4.2500 0.047 0.142 10.09 0.000

4.3333 0.047 0.143 11.60 0.000

4.4167 0.047 0.145 13.17 0.000

4.5000 0.047 0.147 14.81 0.000

4.5833 0.047 0.148 15.96 0.000

4.6667 0.047 0.150 18.06 0.000

4.7500 0.047 0.152 20.77 0.000

4.8333 0.047 0.153 23.98 0.000

4.9167 0.047 0.155 27.60 0.000

5.0000 0.047 0.156 31.57 0.000

5.0833 0.047 0.158 35.83 0.000

5.1667 0.047 0.160 40.34 0.000

5.2500 0.047 0.161 45.04 0.000

5.3333 0.047 0.163 49.88 0.000

5.4167 0.047 0.164 54.81 0.000

5.5000 0.047 0.166 59.77 0.000
1977
160715-SOHM 7/8/2026 3:24:33 PM Page 8
Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area: 4.56
Total Impervious Area: 0
Mitigated Landuse Totals for POC #1
Total Pervious Area: 2.47
Total Impervious Area: 2.09
Flow Frequency Method: Cunnane
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period Flow(cfs)
2 year 1.917294
5 year 2.749176
10 year 3.395606
25 year 4.722952
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 1.917647
5 year 2.581169
10 year 3.123826
25 year 4.713411
3,0 "' 1Cunuaove--1 "'
• ............ ♦♦ ·-+ ,I'
.. 2.59
£
~ 1.79 ~
0 ~ J u.
u. 0.99
10 100
P - ro- not: -W.m - Ex.c..--cl l ng
1978
160715-SOHM 7/8/2026 3:24:48 PM Page 9
Duration Flows
The Facility PASSED
Flow(cfs) Predev Mit Percentage Pass/Fail

0.1917 1989 2001 100 Pass

0.2241 1794 1772 98 Pass

0.2565 1639 1622 98 Pass

0.2888 1505 1488 98 Pass

0.3212 1395 1348 96 Pass

0.3535 1290 1262 97 Pass

0.3859 1200 1175 97 Pass

0.4183 1125 1088 96 Pass

0.4506 1048 1002 95 Pass

0.4830 991 944 95 Pass

0.5154 918 877 95 Pass

0.5477 863 820 95 Pass

0.5801 792 767 96 Pass

0.6124 735 714 97 Pass

0.6448 695 671 96 Pass

0.6772 648 635 97 Pass

0.7095 613 598 97 Pass

0.7419 574 577 100 Pass

0.7743 541 544 100 Pass

0.8066 515 501 97 Pass

0.8390 486 473 97 Pass

0.8713 457 447 97 Pass

0.9037 431 420 97 Pass

0.9361 403 393 97 Pass

0.9684 379 375 98 Pass

1.0008 354 351 99 Pass

1.0332 340 333 97 Pass

1.0655 326 319 97 Pass

1.0979 304 301 99 Pass

1.1302 291 288 98 Pass

1.1626 278 274 98 Pass

1.1950 266 262 98 Pass

1.2273 255 249 97 Pass

1.2597 243 235 96 Pass

1.2921 225 222 98 Pass

1.3244 210 215 102 Pass

1.3568 204 204 100 Pass

1.3891 190 190 100 Pass

1.4215 182 180 98 Pass

1.4539 175 171 97 Pass

1.4862 168 160 95 Pass

1.5186 158 152 96 Pass

1.5509 151 146 96 Pass

1.5833 147 144 97 Pass

1.6157 138 138 100 Pass

1.6480 129 133 103 Pass

1.6804 124 126 101 Pass

1.7128 121 121 100 Pass

1.7451 113 115 101 Pass

1.7775 106 110 103 Pass

1.8098 102 106 103 Pass

1.8422 96 100 104 Pass

1.8746 94 96 102 Pass
1979
160715-SOHM 7/8/2026 3:24:48 PM Page 10

1.9069 92 94 102 Pass

1.9393 81 89 109 Pass

1.9717 79 85 107 Pass

2.0040 78 80 102 Pass

2.0364 74 76 102 Pass

2.0687 72 72 100 Pass

2.1011 69 66 95 Pass

2.1335 67 63 94 Pass

2.1658 63 59 93 Pass

2.1982 60 56 93 Pass

2.2306 57 53 92 Pass

2.2629 54 50 92 Pass

2.2953 52 47 90 Pass

2.3276 51 44 86 Pass

2.3600 49 42 85 Pass

2.3924 48 41 85 Pass

2.4247 47 41 87 Pass

2.4571 46 38 82 Pass

2.4895 44 36 81 Pass

2.5218 40 35 87 Pass

2.5542 38 33 86 Pass

2.5865 38 33 86 Pass

2.6189 37 30 81 Pass

2.6513 32 30 93 Pass

2.6836 32 29 90 Pass

2.7160 31 29 93 Pass

2.7484 29 29 100 Pass

2.7807 28 26 92 Pass

2.8131 26 25 96 Pass

2.8454 23 24 104 Pass

2.8778 23 20 86 Pass

2.9102 22 17 77 Pass

2.9425 21 17 80 Pass

2.9749 20 16 80 Pass

3.0073 20 15 75 Pass

3.0396 20 14 70 Pass

3.0720 18 14 77 Pass

3.1043 18 13 72 Pass

3.1367 15 11 73 Pass

3.1691 15 11 73 Pass

3.2014 15 11 73 Pass

3.2338 14 10 71 Pass

3.2662 14 10 71 Pass

3.2985 14 10 71 Pass

3.3309 13 10 76 Pass

3.3632 13 10 76 Pass

3.3956 12 10 83 Pass
1980
160715-SOHM 7/8/2026 3:24:48 PM Page 11
Water Quality
1981
160715-SOHM 7/8/2026 3:24:48 PM Page 12
Model Default Modifications
Total of 0 changes have been made.

PERLND Changes
No PERLND changes have been made.

IMPLND Changes
No IMPLND changes have been made.
1982
160715-SOHM 7/8/2026 3:24:48 PM Page 13
Appendix
Predeveloped Schematic
C:"'. -=-a Basin 1
- ~.56ac
1983
160715-SOHM 7/8/2026 3:24:48 PM Page 14
Mitigated Schematic
StormTech 1
1984
160715-SOHM 7/8/2026 3:24:48 PM Page 15
Predeveloped UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1949 10 01 END 2006 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> ***
WDM 26 160715-SOHM.wdm
MESSU 25 Pre160715-SOHM.MES
27 Pre160715-SOHM.L61
28 Pre160715-SOHM.L62
30 POC160715-SOHM1.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:15
PERLND 4
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9
END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr ***
in out ***
4 A,Scrub,VSteep(>15%) 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 4 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 4 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
1985
160715-SOHM 7/8/2026 3:24:48 PM Page 16
PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 4 0 0 0 1 0 0 0 0 1 0 0
END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC
4 0 4.2 0.03 250 0.2 0.8 0.955
END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 4 40 35 2 2 0 0.03 0
END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 ***
# - # CEPSC UZSN NSUR INTFW IRC LZETP ***
4 0 0.3 0.3 1.3 0.3 0
END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 4 0.5 0.5 0.5 0.6 0.65 0.65 0.65 0.65 0.65 0.65 0.55 0.5

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 4 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS
4 0 0 0.03 0 0.84 0.3 0.01
END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
END IWAT-PARM2
1986
160715-SOHM 7/8/2026 3:24:48 PM Page 17
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK ***
<Name> # <-factor-> <Name> # Tbl# ***
Basin 1***
PERLND 4 4.56 COPY 501 12
PERLND 4 4.56 COPY 501 13
******Routing******

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer ***
# - #<------------------><---> User T-series Engl Metr LKFG *** in out ***

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG ***

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR *********

END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section ***
# - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * ***
END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 ***
<------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2

HYDR-INIT
RCHRES Initial conditions for each HYDR section ***
# - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><--->

END HYDR-INIT

END RCHRES
1987
160715-SOHM 7/8/2026 3:24:48 PM Page 18

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES

END FTABLES

EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC
WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC
WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP
WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL

END EXT TARGETS

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #***
MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN
END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN
END MASS-LINK 13

END MASS-LINK

END RUN
1988
160715-SOHM 7/8/2026 3:24:48 PM Page 19
Mitigated UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1949 10 01 END 2006 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> ***
WDM 26 160715-SOHM.wdm
MESSU 25 Mit160715-SOHM.MES
27 Mit160715-SOHM.L61
28 Mit160715-SOHM.L62
30 POC160715-SOHM1.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:15
PERLND 1
PERLND 4
IMPLND 1
IMPLND 2
RCHRES 1
COPY 1
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 StormTech 1 MAX 1 2 30 9
END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr ***
in out ***
1 A,Scrub,Flat(0-5%) 1 1 1 1 27 0
4 A,Scrub,VSteep(>15%) 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 1 0 0 1 0 0 0 0 0 0 0 0 0
4 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY
1989
160715-SOHM 7/8/2026 3:24:48 PM Page 20

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 1 0 0 4 0 0 0 0 0 0 0 0 0 1 9
4 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 1 0 0 0 1 0 0 0 0 1 0 0
4 0 0 0 1 0 0 0 0 1 0 0
END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC
1 0 5.2 0.09 400 0.05 0.8 0.955
4 0 4.2 0.03 250 0.2 0.8 0.955
END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 1 40 35 2 2 0 0.03 0
4 40 35 2 2 0 0.03 0
END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 ***
# - # CEPSC UZSN NSUR INTFW IRC LZETP ***
1 0 0.9 0.3 4 0.7 0
4 0 0.3 0.3 1.3 0.3 0
END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 1 0.5 0.5 0.5 0.6 0.65 0.65 0.65 0.65 0.65 0.65 0.55 0.5 4 0.5 0.5 0.5 0.6 0.65 0.65 0.65 0.65 0.65 0.65 0.55 0.5

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 1 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 4 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS
1 0 0 0.09 0 1.04 0.3 0.01
4 0 0 0.03 0 0.84 0.3 0.01
END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***
1 Impervious,Flat(0-5) 1 1 1 27 0
2 Impervious,Mod(5-10) 1 1 1 27 0

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***
1990
160715-SOHM 7/8/2026 3:24:48 PM Page 21
1 0 0 1 0 0 0
2 0 0 1 0 0 0

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********
1 0 0 4 0 0 0 1 9
2 0 0 4 0 0 0 1 9

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
1 0 0 0 0 0
2 0 0 0 0 0
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
1 100 0.05 0.1 0.1
2 100 0.1 0.1 0.09
END IWAT-PARM2
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
1 0 0
2 0 0
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
1 0 0
2 0 0
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK ***
<Name> # <-factor-> <Name> # Tbl# ***
Basin 1***
PERLND 1 0.43 RCHRES 1 2
PERLND 1 0.43 RCHRES 1 3
PERLND 4 2.04 RCHRES 1 2
PERLND 4 2.04 RCHRES 1 3
IMPLND 1 1.93 RCHRES 1 5
IMPLND 2 0.16 RCHRES 1 5
******Routing******
PERLND 1 0.43 COPY 1 12
PERLND 4 2.04 COPY 1 12
IMPLND 1 1.93 COPY 1 15
IMPLND 2 0.16 COPY 1 15
PERLND 1 0.43 COPY 1 13
PERLND 4 2.04 COPY 1 13
RCHRES 1 1 COPY 501 16

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** 1991
160715-SOHM 7/8/2026 3:24:48 PM Page 22
<Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer ***
# - #<------------------><---> User T-series Engl Metr LKFG *** in out ***
1 StormTech 1 1 1 1 1 28 0 1

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section ***
# - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * ***
1 0 1 0 0 4 0 0 0 0 0 0 0 0 0 2 2 2 2 2
END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 ***
<------><--------><--------><--------><--------><--------><--------> *** 1 1 0.04 0.0 3.0 0.5 0.0
END HYDR-PARM2

END HYDR-INIT

END RCHRES

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES
FTABLE 1
66 4
Depth Area Volume Outflow1 Velocity Travel Time***
(ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)***

0.000000 0.048710 0.000000 0.000000

0.083333 0.048710 0.001623 0.028758

0.166667 0.048710 0.003247 0.040670

0.250000 0.048710 0.004871 0.049810

0.333333 0.048710 0.006495 0.057516

0.416667 0.048710 0.008118 0.064305

0.500000 0.048710 0.009742 0.070442

0.583333 0.048710 0.011365 0.076087

0.666667 0.048710 0.012989 0.081340

0.750000 0.048710 0.014613 0.086274

0.833333 0.048710 0.018201 0.090941

0.916667 0.048710 0.021771 0.095380

1.000000 0.048710 0.025330 0.099621

1.083333 0.048710 0.028877 0.103689

1.166667 0.048710 0.032412 0.107603

1.250000 0.048710 0.035932 0.111379

1.333333 0.048710 0.039443 0.115032
1992
160715-SOHM 7/8/2026 3:24:48 PM Page 23

1.416667 0.048710 0.042937 0.118572

1.500000 0.048710 0.046417 0.122010

1.583333 0.048710 0.049881 0.125353

1.666667 0.048710 0.053328 0.128610

1.750000 0.048710 0.056758 0.131786

1.833333 0.048710 0.060171 0.134887

1.916667 0.048710 0.063564 0.137919

2.000000 0.048710 0.066937 0.140885

2.083333 0.048710 0.070290 0.143790

2.166667 0.048710 0.073620 0.146638

2.250000 0.048710 0.076926 0.149431

2.333333 0.048710 0.080209 0.152173

2.416667 0.048710 0.083465 0.154867

2.500000 0.048710 0.086694 0.157514

2.583333 0.048710 0.089895 0.160118

2.666667 0.048710 0.093065 0.162680

2.750000 0.048710 0.096204 0.165202

2.833333 0.048710 0.099309 0.167687

2.916667 0.048710 0.102380 0.170135

3.000000 0.048710 0.105413 0.172548

3.083333 0.048710 0.108406 0.174928

3.166667 0.048710 0.111360 0.177276

3.250000 0.048710 0.114271 0.179594

3.333333 0.048710 0.117135 0.181882

3.416667 0.048710 0.119944 0.195878

3.500000 0.048710 0.122706 0.547637

3.583333 0.048710 0.125409 1.133361

3.666667 0.048710 0.128051 1.880092

3.750000 0.048710 0.130621 2.758381

3.833333 0.048710 0.133121 3.750793

3.916667 0.048710 0.135536 4.845423

4.000000 0.048710 0.137855 6.033469

4.083333 0.048710 0.140047 7.308077

4.166667 0.048710 0.142054 8.663713

4.250000 0.048710 0.143904 10.09579

4.333333 0.048710 0.145691 11.60041

4.416667 0.048710 0.147423 13.17423

4.500000 0.048710 0.149080 14.81433

4.583333 0.048710 0.150755 15.96499

4.666667 0.048710 0.152378 18.06484

4.750000 0.048710 0.154002 20.77946

4.833333 0.048710 0.155626 23.98499

4.916667 0.048710 0.157249 27.60297

5.000000 0.048710 0.158873 31.57197

5.083333 0.048710 0.160496 35.83737

5.166667 0.048710 0.162121 40.34689

5.250000 0.048710 0.163744 45.04840

5.333333 0.048710 0.165368 49.88896

5.416667 0.048710 0.166991 54.81463
END FTABLE 1

END FTABLES

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL
RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL
COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL
COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL

END EXT TARGETS
1993
160715-SOHM 7/8/2026 3:24:48 PM Page 24

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #***
MASS-LINK 2
PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL
END MASS-LINK 2
MASS-LINK 3
PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL
END MASS-LINK 3
MASS-LINK 5
IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL
END MASS-LINK 5
MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN
END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN
END MASS-LINK 13
MASS-LINK 15
IMPLND IWATER SURO 0.083333 COPY INPUT MEAN
END MASS-LINK 15
MASS-LINK 16

RCHRES ROFLOW COPY INPUT MEAN
END MASS-LINK 16

END MASS-LINK

END RUN
1994
160715-SOHM 7/8/2026 3:24:48 PM Page 25
Predeveloped HSPF Message File
1995
160715-SOHM 7/8/2026 3:24:48 PM Page 26
Mitigated HSPF Message File
1996
160715-SOHM 7/8/2026 3:24:48 PM Page 27
Disclaimer
Legal Notice
This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2026; All Rights Reserved.

Clear Creek Solutions, Inc.
6200 Capitol Blvd. Ste F
Olympia, WA. 98501
Toll Free 1(866)943-0304
Local (360)943-0304
www.clearcreeksolutions.com
1997
Water Quality Management Plan (WQMP)

Presidio

Attachment G: DRAINAGE REPORT
1998
PRELIMINARY DRAINAGE REPORT: Tract No. 19489
Proposed 58-Unit Townhome Development
Aliso Viejo, California
ACG Project No. 106715
May 28, 2026
Site Location:
15 Argonaut
Aliso Viejo, CA 92656

Prepared For:

Brandywine Homes
2355 Main Street, Suite 220
Irvine, CA 92614
Prepared By:

Advanced Civil Group, Inc.
30251 Golden Lantern, Suite E PMB 251
Laguna Niguel, CA 92677
(866) 338-5778
advancedcivilgroup.com
1999
1 Table of Contents
Contents
INTRODUCTION .............................................................................................................................................. 2 HYDROLOGY ................................................................................................................................................... 6 CONCLUSION .................................................................................................................................................. 7 Figures and Tables
Figure 1 - Area Map............................................................................................................................................ 3 Figure 2 - Vicinity Map ....................................................................................................................................... 4 Table 1 - Rational Method Results .................................................................................................................... 7 Attachments
Pervious Area Exhibits
Hydrology Exhibits
Time of Concentration Nomograph
Mean Precipitation Intensities
Rational Method Hydrology Calculation
2000
2 INTRODUCTION
Project Description
The proposed development at 15 Argonaut (“Property”) consists of a proposed 58-unit townhome development (“Project”). The Project is in Aliso Viejo (“City”), County of Orange (“County”). The area of the Property is 4.40 acres known as Assessor Parcel Number’s 623-093-10 and 623-093-11.

Existing commercial developments border the Property to the south and east. An existing hillside and v-ditches are located on the north and west portions of the Property (See Figure 1 - Area Map and Figure 2 - Vicinity Map).

The central to southeast portion of the existing property is relatively flat and contains a commercial building, drive aisles, and parking. The north and west side of the property consists of a 2:1 hillside slope which drains to v-ditches. The runoff from the v-ditches discharge to the surface and flow to the front of the property along with all other surface flows where it discharges to Argonaut via under sidewalk drains.

Project Objectives
The objectives of this study are listed below.

1. Use the Rational Method to determine the 10-Year Storm peak flow rates for the existing and proposed conditions.

2. Demonstrate that all habitable structures and protected for the 100-Year Storm Event.

3. Prepare Final Drainage Study based on objectives above. 2001
3 Figure 1 - Area Map
Project
0 Art-Pnme
Appliance Repair
•Pobo11~
...

Ridgecrest
Park
- Jt::SU:S \..Ill l:Sl 01 Lclllt:I...

Harbor station Tot Lot 0
Glenwood Aliso
Creek Auto Repair
Comple- e Al.no
Repair & Senic:e
Brookline Park
ElectroSport O .,
:I ! qj
Public storage 0
()()110' o\e(\~
Ambry Genetics 0 @ Onsite Dental
~ Tummy stuffer,
AhsoV1eJO \
a
Pacific Ballet
Conservatory Dance school
Parable Hospitality 0
stor-11 Self storage 0
... ... Progressive Q
Orthodontics
Pinewood Park 0 <
Argonaut Park
... ...
/' ..
cil
Rainy,1004
2002
4 Figure 2 - Vicinity Map
Project
Willow
_._.,_7 ···
Canyon Alize at Aliso Viejo a View Park Apartment Homes ~ Laguna
Woods
E:] The Home Depot
O compass Bible Church
Jeik·s seed &
stars Daycare

ACACI A KNOLLS
Laguna Hills
I
I
2003
5 Existing Facilities
The central to southeast portion of the property is relatively flat and contains a commercial building, drive aisles, and parking. The north and west side of the property consists of a 2:1 hillside slope which drains to v-ditches. The runoff from the v-ditches discharge to the surface and flow to the front of the property along with all other surface flows where it discharges to Argonaut via under sidewalk drains.

Proposed Facilities
The proposed redevelopment replaces an existing commercial property that slopes from northwest to southeast. The northern and western boundaries feature a 2:1 hillside slope with vditches that intercept runoff; under the new design, this drainage will be conveyed through underground pipes to the front of the property, maintaining existing hydraulic patterns. Onsite stormwater will be collected via area drains and directed to a biofiltration system for treatment before being pumped for final discharge into Argonaut.
2004
6 HYDROLOGY
Methodology
The tributary drainage area boundaries were delineated utilizing topography from aerial photogrammetry over the Project site and surrounding areas. The proposed Project drainage design found on the attached Site BMP Locations exhibit illustrates the locations of onsite drainage systems.

Rational Method
The Rational Method, an empirical computational procedure for developing peak runoff and discharge for storms of a specified recurrence interval in small watersheds, was used to compute peak flow rates for the watersheds tributary to the Project. The Orange County Hydrology Manual provides a Rational Method formula to calculate the peak runoff. The Rational Method formula is:

Q = CIA
Where:

Q = Peak discharge, in cubic feet per second (cfs)
C = Runoff coefficient representing the ratio of runoff depth to rainfall depth = 0.90 (ai + ((1-Fp) ap)/I) for I greater than Fp; 0.90 ai for I less than or equal to Fp ai = ratio of impervious area to total area (decimal fraction) ap = ration of pervious area to total are (decimal fraction), (ap = 1 – ai) Fp = infiltration rate for pervious area (inches per hour) I = The time-averaged rainfall intensity for a storm duration equal to the time of concentration, in inches/hour (in/hr)
A = Drainage area, in acres (ac)
Hydrology Summary
The peak flow rate for the 10-year storm event was calculated using the Rational Method. The results of these calculations are presented in Table 1 below. Supporting documentation for these results is included in the attachments.
2005
7 Table 1 - Rational Method Results
10-Year Existing
Storm Event
10-Year Proposed
Storm Event
Drainage Area 1 8.10 cfs 7.57 cfs
Drainage Area 2 0.68 cfs 0.68 cfs
Drainage Area 3 0.67 cfs 0.67 cfs
Drainage Area 4 0.58 cfs 0.58 cfs
The 10-year Rational Method analysis shows that the proposed condition maintains or slightly reduces peak flows compared to existing conditions, with Drainage Area 1 decreasing from

8.10 cfs to 7.57 cfs and the other areas remaining unchanged. 100-Year Storm Protection
The project site is not located within a mapped FEMA Special Flood Hazard Area (SFHA), as confirmed by FEMA FIRMette Panel 06059C0426J, effective date 12/3/2009. Based on this determination, the site is outside of the 100-year floodplain and is not subject to mapped flood zone inundation.

All proposed habitable structures have been designed and graded such that finished floor elevations are above the adjacent public and private street elevations, providing positive drainage away from the buildings. Surface runoff generated by the 100-year storm event will be collected and conveyed through proposed on-site drainage improvements and/or adjacent street conveyance systems in accordance with Orange County Local Drainage Manual requirements.

CONCLUSION
Based on the Rational Method analysis, the proposed Project drainage design will not increase peak runoff for the 10-year storm event. Peak flows are either maintained or slightly reduced compared to existing conditions, demonstrating that the Project’s on-site drainage systems effectively manage runoff. Therefore, the proposed development meets the hydrology performance objectives and is consistent with the requirements of the Orange County Hydrology Manual.
2006
8 Attachments
2007
30251 GOLDEN LANTERN,
SUITE E, PMB 251
LAGUNA NIGUEL, CA 92647
(866) 338-5778 PHONE
DRAINAGE AREA 1

3.16 AC
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC
DRAINAGE AREA 4

0.79 AC
----1
-==
J
80 40 0 80 160 240
~I~~ I __ II
SCALE: 1"=80'

TOTAL AREA
~t-.~=.·;•=.,:·,.-i·,:=:..::j TOT AL PER VI OU S AR EA
% PERVIOUS
% IMPERVIOUS
DRAINAGE AREA 1
~t·:-:-=,·;•=.;:,,.-i·t=:..::-J TOTAL PERVIOUS AREA
% PERVIOUS
% IMPERVIOUS
DRAINAGE AREA 2
..-.t.,~=:;7=.,:-,.=;.,:=:..::-J TOTAL PERVIOUS AREA
% PERVIOUS
% IMPERVIOUS
DRAINAGE AREA 3
~t-,.~=.·;•=.,:·,.-i·,:=:..::-J TOT AL PER VI OU S AR EA % PERVIOUS
% IMPERVIOUS
DRAINAGE AREA 4
~t·:-:-=:;7=.~:-,.-;.,:=:..::j TOT AL PER VI OU S AR EA % PERVIOUS
% IMPERVIOUS

ADVANCED

CIVIL GROUP

4.56 AC

2.45 AC
53 %
47 %

3.16 AC

1.21 AC
38 %
62 %

0.35 AC

0.31 AC
89 %
11 %

0.26 AC

0.24 AC
92 %
8 %

0. 79 AC

0.69 AC
87 %
13 %
ADVANCED CIVIL GROUP INC.

WWW.ADVANCEDCIVILGROUP .COM
R.C .E. NO. 68795
DA TE 3/31/2026

PERVIOUS AREA

EXISTING CONDITION
15 ARGONAUT

ALISO VIEJO
2008
//
// DW
DW
DW
DW
DW
DW
DW

DW DW DW DW DW DW DW
SS
SS
SS
SS
SS
SS
SS

SS SS SS SS SS
SS

SS SS SS SS SS SS SS SS SS
DW
30251 GOLDEN LANTERN,
SUITE E, PMB 251
LAGUNA NIGUEL, CA 92647
(866) 338-5778 PHONE
DRAINAGE AREA 1

3.16 AC
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC
DRAINAGE AREA 4

0.79 AC
80 40 0 80 160 240
I r,,zj...1------~-'~I ~'!_'!_'!__IC\----~1
SCALE: 1''= 80'

TOTAL AREA
~f ...~:: :--::,,~:-::] fOT AL PERVIOUS AREA
% PER VI OUS
% IMPERVIOUS
DRAI NAG E AREA 1
~f·:~i:":-,~-,~;:-1 fOT AL PERVIOUS AREA
% PER VIOU S
% IMPERVIOUS
DRAIN AG E AREA 2
r.-.....,,,; . ..,-"""";S,,.,,.,,,~-:;=~·-1 TOT AL PERVIOUS AREA % PERVIOUS
% IM PER VIOUS
DRAINAGE AR EA 3
f~.,..,.~;t,:-,.i·,~~-::j TO TAL PER VI OUS AREA
% PERVIOUS
% IM PERVIOUS
DRAINAGE AREA 4
~t-,-.,·~;z.~:-,.~-,~-~-::j TOTAL PERVIOUS AR EA
% PERVIOUS
% IMPERVIOUS

ADVANCED

CIVI L GROUP

4. 56 AC

2. 36 AC
52 %
48 %

3.1 6 AC

1.12 AC
3 5 %
6 5 %
0 .3 5 AC
0 .31 AC
89 %
11 %

0.2 6 AC

0.24 AC
9 2 %
8 %

0.79 AC

0.69 AC
8 7 %
13 %
ADVANCED CIVIL GROUP INC.

WWW.ADVANCEDCIVILGROUP.COM
R.C.E. NO. 68795
DATE 4/8/2026

PERVIOUS AREA

PROPOSED CONDITION
15 ARGONAUT

ALISO VIEJO
2009
460.00 FL
DRAINAGE AREA 1

3.16 AC
LENGTH = 522 LF
SLOPE = 0.009
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC DRAINAGE AREA 4 0.79 AC
LENGTH = 202 LF
SLOPE = 0.146
489.50 FL
462.00 FL
489.20 FL
LENGTH = 147 LF
SLOPE = 0.185
461.00 FL
LENGTH = 302 LF
SLOPE = 0.093

ARGONAUT

GLENWOOD DRIVE

ALISO CREEK ROAD
456.50
INV
461.00
FL
EXISTING HYDROLOGY EXHI Bl T

IN THE CITY OF ALISO VIEJO,

COUNTY OF ORANGE, STATE OF CALIFORNIA
))1111'1~ ,-.\\,
\\
\
~
PROPERTY ADDRESS=
15 ARGONAUT
ALISO VIEJO, CA 92656
DRAINAGE AREA=

OMA (AC)
1 3.16
2 0.48
3 0.30
4 0.79
LEGEND:
- > - > - FLOW PA TH
- - - - - DRAINAGE BOUNDARY
0 [XJ
II
w
_J
<(
u
CJl
80 40 O 80 160 240
I ~1-----1~~1 I
SCALE: 1"=80'
2010
DW
DW
DW
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DW

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SS
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DW

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SS

SD SD SD SD SD SD

SD SD SD SD

SD SD SD SD SD SD

SD SD SD
DW
//
// 460.00 FL
DRAINAGE AREA 1

3.16 AC
LENGTH = 531 LF
SLOPE = 0.017
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC DRAINAGE AREA 4 0.79 AC
LENGTH = 202 LF
SLOPE = 0.146
489.50 FL
462.00 FL
489.20 FL
LENGTH = 147 LF
SLOPE = 0.185
461.00 FL
LENGTH = 302 LF
SLOPE = 0.093

ARGONAUT

GLENWOOD DRIVE

ALISO CREEK ROAD
451.50
INV
460.81
FS

PROPOSED HYDROLOGY EXHIBIT

IN THE CITY OF ALISO VIEJO,

COUNTY OF ORANGE, STATE OF CALIFORNIA
PROPERTY ADDRESS=
15 ARGONAUT
ALISO VIEJO, CA 92656
DRAINAGE AREA=
OMA
1 2
3 4
LEGEND:
(AC)

3.16 0.48

0.30 0. 79
- > - > - FLOW PA TH
- - - - - DRAINAGE BOUNDARY
0 [XJ
II
w
_J
<(
u
CJl
80 40 O 80 160 240
I ~/-------1~~~~1---I -~1
SCALE: 1"=80'
2011
0 ~ 0
c
.5
-
0 L
1000
900
500
400
350
300
250
200
150
100
...
i
E
Q,
0 -;
i
-0
...
.e.

Ill
Q)
!;
C
E
.5
C
0 ;
0 ...
c
g
0 u
Q)
E
.=
LIMITATIONS=
I. Maximum length = 1000 Feet

2. Maximum area = 10 Acres
...

C
Q) . !
(/)
~
li
K
Undeveloped
Good Cover
Undeveloped
Fair Cover
Undeveloped
Poor Cover
Commercial
~ Q) rs..-0 .. - Cl-Ill
0 -0 ,._ C i Q)
~ C
Q) Q)

0.. Q)
-::--3
p• Q) .!l ..Q
0 0
100
80 60
40 30
20 10
8 6
;~
2 14 (Paved) KEY
L-H-Tc-K-Tc' 13 /
12 ,i." / 11/ C
10 9
8 7
6 5
4 eL Development
80- Apartment
75- Mobile Home
65- Condominium
60- Single Fomily-5,000 ft 2 Lot
40- Single Family-1/4 Acre Lot
20- Single Family- I Acre Lot
15 - Developed Open Space
10 - Single Family-21/2 Acre Lot
EXAMPLE:
(I) L= 5501
, H=5.01, K=Slngle Family (5-7 DU/AC}
Development, Tc=l2.6 min.
(2) L= 550., H= 5.0', K= Commercial
Development, Tc=9.7 min.

Tc
5 (min)
6 7
8 9
10 I I
25 30
35 40
::-
E
0 LL
...
0 -
.s
.....
u
....
-
C
0 "ij
...
-
C
B
C
0 u
-
0 Q)
E
I=
---------------------1
ORANGE COUNTY.

HYDROLOGY MANUAL

TIME OF CONCENTRATION

NOMOGRAPH

FOR INITIAL SUBAREA
D-4 Figure D-I 2012
a:
::,
0 :l:
' U)
uJ
:l:
0 z
Regression Equations: I(t)= atb
(I= Intensity in inches/hour, t= duration in minutes)
Return Frequency
(years)
2 5
10 25
50 100
a

5.702

7.870

10.209

11. 995

13.521

15.560
b
-0.574
-0.562
-0.573
-0.566
-0.566
-0.573
RETURN PcRI00
100 YR
50 YR
25 YR
10 YR
5 YR
2 YR

PRECIPITATION DURATION (MIN)

ORANGE COUNTY

HYDROLOGY MANUAL
B-7

MEAN PRECIPITATION

INTENSITIES FOR

NONMOUNTAINOUS AREAS
Figure B-3 2013
OC Hydrology Manual
Section D - Rational Method
Fp is from Section C.6.4 of OC Hydrology Manual (soil type A) I is from OC Hydrology Manual Figure B-3
Drainage Area 1 Drainage Area 1
10-Year Existing 10-Year Proposed
ai 0.62 ai 0.65
ap 0.38 ap 0.35
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.85 C 0.86
I 3.0 in/hr I 2.8 in/hr
A 3.16 acres A 3.16 acres
Q 8.10 cfs Q 7.57 cfs
Drainage Area 2 Drainage Area 2
10-Year Existing 10-Year Proposed
ai 0.11 ai 0.11
ap 0.89 ap 0.89
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.77 C 0.77
I 2.5 in/hr I 2.5 in/hr
A 0.35 acres A 0.35 acres
Q 0.68 cfs Q 0.68 cfs
Drainage Area 3 Drainage Area 3
10-Year Existing 10-Year Proposed
ai 0.08 ai 0.08
ap 0.92 ap 0.92
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.77 C 0.77
I 2.5 in/hr I 2.5 in/hr
A 0.35 acres A 0.35 acres
Q 0.67 cfs Q 0.67 cfs
15 Argonaut
Rational Method Hydrology Calculation
5/19/2026
2014
Drainage Area 4 Drainage Area 4
10-Year Existing 10-Year Proposed
ai 0.13 ai 0.13
ap 0.87 ap 0.87
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.76 C 0.76
I 2.2 in/hr I 2.2 in/hr
A 0.35 acres A 0.35 acres
Q 0.58 cfs Q 0.58 cfs
2015
Water Quality Management Plan (WQMP)

Presidio

Attachment H: MAINTENANCE COVENANT AND

AGREEMENT
2016

RECORDING REQUESTED BY
AND MAIL TO:

CITY OF ALISO VIEJO

PUBLIC WORKS DEPARTMENT
12 JOURNEY
ALISO VIEJO, CA 92656
Space above this line is for Recorder’s use

MAINTENANCE COVENANT AND AGREEMENT FOR

WATER QUALITY MANAGEMENT PLAN (WQMP) REQUIREMENTS
The undersigned hereby certifies I am (we are) the owner(s) (“Owner(s)”) of the hereinafter described real property located in the City of Aliso Viejo, County of Orange, State of California (“Property”):

Site Address: ___________________________ APN: ___________________________ Please attach the legal description for the Property as Attachment 1.

Owner and its heirs, successors, and assigns, including each successive owner of an interest in all or any part of the Property shall, throughout the period of their respective ownership, implement, and fund implementation of, the Operations & Maintenance (“O&M”) Plan for the Property, which was approved by the City as part of the Water Quality Management Plan (“WQMP”) required for development of the Property, and shall operate, inspect, maintain, repair, and replace the Best Management Practices (“BMPs”) described in the O&M Plan for the Property, which includes:
• Description of all post‑construction BMPs (non‑structural and structural) • WQMP BMP Site Plan
• Description of the Owner’s responsibilities and required training of persons performing BMP implementation, operation, maintenance, and inspection
• Implementation/inspection/maintenance frequency and operating schedule • Specific BMP implementation, maintenance, and inspection activities • Description of all permits required for the implementation, operation, and maintenance of BMPs • Forms to be used in documenting implementation, operation, maintenance, and inspection of BMPs • Recordkeeping requirements
Please attach copies of the approved O&M Plan and WQMP BMP Site Plan as Attachment 2 to this Agreement for recordation.

A copy of the approved O&M Plan is described in the current WQMP for the project, as it may be amended from time to time according to its terms, which is on file with the City of Aliso Viejo and is incorporated herein by this reference.

Owner(s) shall maintain the drainage devices described in the O&M Plan for the Property indicated and as shown on plans permitted by the City of Aliso Viejo in good and functional condition to safeguard the property owners and adjoining properties from damage and pollution.

Owner(s) hereby consent to inspection of the Property by an inspector authorized by the City Manager, or his or her designee, for the purpose of verifying compliance with the provisions of this Agreement.

Owner(s) shall provide printed educational materials with any sale of the property which provide information on what stormwater management facilities are present, the type(s) and location(s) of maintenance signs that are required, and how the necessary maintenance can be performed.

Owner(s) shall provide actual notice of this Agreement and its terms to any respective successor(s) in interest to the Property prior to transfer of said interest to such successor(s) in interest. This covenant and agreement shall run with the land and shall be binding upon any future owners, encumbrances, their successors, heirs or assigns and shall continue in effect until the City of Aliso Viejo approves its termination.

Print Name of Owner(s): 1.___________________________, 2._____________________________ Signature of Owner(s):
1:____________________________ Date:_______________________ 2:____________________________ Date:_______________________ (ATTACH NOTARY)
2017
DW DW
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SS SS SS SS SS SS SS SS

DW DW DW DW DW DW DW DW DW DW DW DW DW DW DW DW DW DW DW

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SS SS
DW

SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS

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I"(
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/1,('l-1'li'Kffe.l--/-!...i,l.\l
' '
•
T
l

WQMP SITE PLAN

IN THE CITY OF ALISO VIEJO

COUNTY OF ORANGE, STATE OF CALIFORNIA
_ ___ ,
J
' I -r-- i ( '
t--
- __ .t
..,,
' GL~Nwoo DR
) 'l -----
i
+ / /
_j__
' -
--
-- _/ -- ~:::::--====~~s=i~:~~~~~ ----==- -- _0-;;3/ _____ ----- ~--:-::::--=::::::,; I I
~~~~~~~181;!..)....I I I
I
I INLEl ~ 1W/ TER '2__y
:, ," RAIN INLET
-------~
__ ,1(c~v / -"F,l_l..TER
0 ®t

STORM AIN CHAMBER
-
-
181
181
@ • r· @
@
@
r RESIDIO
---ILANE
_J DRAIN INLET wii rn:
--------- DRAIN INLET ,'
W/ FILTER i
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D AREA RUN
~ ) BIOFIL
'
-
--
•
,- @
--
-, '
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\ r ~/~· _A_R_GO_.._N_AUT
I ) -
';, < /'
,: isl J, r- '\_ (.!) ~:
"• l ~ rli ,/~-r .. C
PROPERTY ADDRESS=
15 ARGONAUT
ALISO VIEJO, CA 92656
30 15 0 30 60 90 l~~f-----1
__
1----'I
SCALE: 1''=30'
2018
FCS
F.2 - Drainage Report
•• • FCS
An ADEC Innovation
2019

THIS PAGE INTENTIONALLY LEFT BLANK
2020
PRELIMINARY DRAINAGE REPORT: Tract No. 19489
Proposed 58-Unit Townhome Development
Aliso Viejo, California
ACG Project No. 106715
July 14, 2026
Site Location:
15 Argonaut
Aliso Viejo, CA 92656

Prepared For:

Brandywine Homes
2355 Main Street, Suite 220
Irvine, CA 92614
Prepared By:

Advanced Civil Group, Inc.
30251 Golden Lantern, Suite E PMB 251
Laguna Niguel, CA 92677
(866) 338-5778
advancedcivilgroup.com
2021
1 Table of Contents
Contents
INTRODUCTION .............................................................................................................................................. 2 HYDROLOGY ................................................................................................................................................... 6 CONCLUSION .................................................................................................................................................. 7 Figures and Tables
Figure 1 - Area Map............................................................................................................................................ 3 Figure 2 - Vicinity Map ....................................................................................................................................... 4 Table 1 - Rational Method Results .................................................................................................................... 7 Attachments
Pervious Area Exhibits
Hydrology Exhibits
Time of Concentration Nomograph
Mean Precipitation Intensities
Rational Method Hydrology Calculation
2022
2 INTRODUCTION
Project Description
The proposed development at 15 Argonaut (“Property”) consists of a proposed 58-unit townhome development (“Project”). The Project is in Aliso Viejo (“City”), County of Orange (“County”). The area of the Property is 4.40 acres known as Assessor Parcel Number’s 623-093-10 and 623-093-11.

Project Objectives
The objectives of this study are listed below.

1. Use the Rational Method to determine the 10-Year Storm peak flow rates for the existing and proposed conditions.

2. Demonstrate that all habitable structures and protected for the 100-Year Storm Event.

3. Prepare Final Drainage Study based on objectives above. 2023
3 Figure 1 - Area Map
Project
0 Art-Pnme
Appliance Repair
•Pobo11~
...

Ridgecrest
Park
- Jt::SU:S \..Ill l:Sl 01 Lclllt:I...

Harbor station Tot Lot 0
Glenwood Aliso
Creek Auto Repair
Comple- e Al.no
Repair & Senic:e
Brookline Park
ElectroSport O .,
:I ! qj
Public storage 0
()()110' o\e(\~
Ambry Genetics 0 @ Onsite Dental
~ Tummy stuffer,
AhsoV1eJO \
a
Pacific Ballet
Conservatory Dance school
Parable Hospitality 0
stor-11 Self storage 0
... ... Progressive Q
Orthodontics
Pinewood Park 0 <
Argonaut Park
... ...
/' ..
cil
Rainy,1004
2024
4 Figure 2 - Vicinity Map
Project
Willow
_._.,_7 ···
Canyon Alize at Aliso Viejo a View Park Apartment Homes ~ Laguna
Woods
E:] The Home Depot
O compass Bible Church
Jeik·s seed &
stars Daycare

ACACI A KNOLLS
Laguna Hills
I
I
2025
5 Existing Facilities
The central to southeast portion of the property is relatively flat and contains a commercial building, drive aisles, and parking. The north and west side of the property consists of a 2:1 hillside slope which drains to v-ditches. The runoff from the v-ditches discharge to the surface and flow to the front of the property along with all other surface flows where it discharges to Argonaut via under sidewalk drains.

Proposed Facilities
The proposed redevelopment replaces an existing commercial property that slopes from northwest to southeast. The northern and western boundaries feature a 2:1 hillside slope with vditches that intercept runoff; under the new design, this drainage will be conveyed through underground pipes to the front of the property, maintaining existing hydraulic patterns. Onsite stormwater will be collected via area drains and directed to underground storage chambers which are proposed to mitigate the peak flow per hydromodification requirements. Runoff will exit the storage chambers at a designed flow rate and then pumped to a biofiltration system for treatment before being pumped for final discharge into Argonaut.
2026
6 HYDROLOGY
Methodology
The tributary drainage area boundaries were delineated utilizing topography from aerial photogrammetry over the Project site and surrounding areas. The proposed Project drainage design found on the attached Site BMP Locations exhibit illustrates the locations of onsite drainage systems.

Q = CIA
Where:

Q = Peak discharge, in cubic feet per second (cfs)
C = Runoff coefficient representing the ratio of runoff depth to rainfall depth = 0.90 (ai + ((1-Fp) ap)/I) for I greater than Fp; 0.90 ai for I less than or equal to Fp ai = ratio of impervious area to total area (decimal fraction) ap = ration of pervious area to total are (decimal fraction), (ap = 1 – ai) Fp = infiltration rate for pervious area (inches per hour) I = The time-averaged rainfall intensity for a storm duration equal to the time of concentration, in inches/hour (in/hr)
A = Drainage area, in acres (ac)
Hydrology Summary
The peak flow rate for the 10-year storm event was calculated using the Rational Method. The results of these calculations are presented in Table 1 below. Supporting documentation for these results is included in the attachments.
2027
7 Table 1 - Rational Method Results
10-Year Existing
Storm Event
10-Year Proposed
Storm Event
Drainage Area 1 8.10 cfs 7.57 cfs
Drainage Area 2 0.68 cfs 0.68 cfs
Drainage Area 3 0.67 cfs 0.67 cfs
Drainage Area 4 0.58 cfs 0.58 cfs
The 10-year Rational Method analysis shows that the proposed condition maintains or slightly reduces peak flows compared to existing conditions, with Drainage Area 1 decreasing from

CONCLUSION
Based on the Rational Method analysis, the proposed Project drainage design will not increase peak runoff for the 10-year storm event. Peak flows are either maintained or slightly reduced compared to existing conditions, demonstrating that the Project’s on-site drainage systems effectively manage runoff. Therefore, the proposed development meets the hydrology performance objectives and is consistent with the requirements of the Orange County Hydrology Manual.
2028
8 Attachments
2029
30251 GOLDEN LANTERN,
SUITE E, PMB 251
LAGUNA NIGUEL, CA 92647
(866) 338-5778 PHONE
DRAINAGE AREA 1

3.16 AC
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC
DRAINAGE AREA 4

0.79 AC
----1
-==
J
80 40 0 80 160 240
~I~~ I __ II
SCALE: 1"=80'

ADVANCED

CIVIL GROUP

4.56 AC

2.45 AC
53 %
47 %

3.16 AC

1.21 AC
38 %
62 %

0.35 AC

0.31 AC
89 %
11 %

0.26 AC

0.24 AC
92 %
8 %

0. 79 AC

0.69 AC
87 %
13 %
ADVANCED CIVIL GROUP INC.

WWW.ADVANCEDCIVILGROUP .COM
R.C .E. NO. 68795
DA TE 3/31/2026

PERVIOUS AREA

EXISTING CONDITION
15 ARGONAUT

ALISO VIEJO
2030
//
// DW
DW
DW
DW
DW
DW
DW

DW DW DW DW DW DW DW
SS
SS
SS
SS
SS
SS
SS

SS SS SS SS SS
SS

SS SS SS SS SS SS SS SS SS
DW
30251 GOLDEN LANTERN,
SUITE E, PMB 251
LAGUNA NIGUEL, CA 92647
(866) 338-5778 PHONE
DRAINAGE AREA 1

3.16 AC
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC
DRAINAGE AREA 4

0.79 AC
80 40 0 80 160 240
I r,,zj...1------~-'~I ~'!_'!_'!__IC\----~1
SCALE: 1''= 80'

ADVANCED

CIVI L GROUP

4. 56 AC

2. 36 AC
52 %
48 %

3.1 6 AC

1.12 AC
3 5 %
6 5 %
0 .3 5 AC
0 .31 AC
89 %
11 %

0.2 6 AC

0.24 AC
9 2 %
8 %

0.79 AC

0.69 AC
8 7 %
13 %
ADVANCED CIVIL GROUP INC.

WWW.ADVANCEDCIVILGROUP.COM
R.C.E. NO. 68795
DA TE 7/8/2026

PERVIOUS AREA

PROPOSED CONDITION
15 ARGONAUT

ALISO VIEJO
2031
460.00 FL
DRAINAGE AREA 1

3.16 AC
LENGTH = 522 LF
SLOPE = 0.009
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC DRAINAGE AREA 4 0.79 AC
LENGTH = 202 LF
SLOPE = 0.146
489.50 FL
462.00 FL
489.20 FL
LENGTH = 147 LF
SLOPE = 0.185
461.00 FL
LENGTH = 302 LF
SLOPE = 0.093

ARGONAUT

GLENWOOD DRIVE

ALISO CREEK ROAD
456.50
INV
461.00
FL
EXISTING HYDROLOGY EXHI Bl T

IN THE CITY OF ALISO VIEJO,

COUNTY OF ORANGE, STATE OF CALIFORNIA
))1111'1~ ,-.\\,
\\
\
~
PROPERTY ADDRESS=
15 ARGONAUT
ALISO VIEJO, CA 92656
DRAINAGE AREA=

OMA (AC)
1 3.16
2 0.48
3 0.30
4 0.79
LEGEND:
- > - > - FLOW PA TH
- - - - - DRAINAGE BOUNDARY
0 [XJ
II
w
_J
<(
u
CJl
80 40 O 80 160 240
I ~1-----1~~1 I
SCALE: 1"=80'
2032
DW
DW
DW
DW
DW
DW
DW

DW DW DW DW DW DW DW
SS
SS
SS
SS
SS
SS

DW DW DW
DW
SS

SS SS SS SS SS SS SS SS SS SS SS SS

DW DW DW DW SS SS SS DW DW
DW

DW DW DW

SS SS SS SS SS SS SS
DW DW
SS SS

DW DW SS SS
SS
SS
DW
SS DW

SD SD SD SD SD SD
SD

SD SD SD SD
DW
SD SD
//
// 460.00 FL
DRAINAGE AREA 1

3.16 AC
LENGTH = 531 LF
SLOPE = 0.017
DRAINAGE AREA 2

0.35 AC
DRAINAGE AREA 3

0.26 AC DRAINAGE AREA 4 0.79 AC
LENGTH = 202 LF
SLOPE = 0.146
489.50 FL
462.00 FL
489.20 FL
LENGTH = 147 LF
SLOPE = 0.185
461.00 FL
LENGTH = 302 LF
SLOPE = 0.093

ARGONAUT

GLENWOOD DRIVE

ALISO CREEK ROAD
451.50
INV
460.81
FS

PROPOSED HYDROLOGY EXHIBIT

IN THE CITY OF ALISO VIEJO,

COUNTY OF ORANGE, STATE OF CALIFORNIA
PROPERTY ADDRESS:
15 ARGONAUT
ALISO VIEJO, CA 92656
DRAINAGE AREA=
OMA
1 2
3 4
LEGEND:
(AC)

3.16 0.48

0.30 0. 79
->->- FLOW PATH
- - - - - DRAINAGE BOUNDARY
0 CX)
II
w
_J
<(
u
lf)
80 40 O 80 160 240
I ~1-----1~~~~!----I --1
SCALE: 1"=80'
2033
0 ~ 0
c
.5
-
0 L
1000
900
500
400
350
300
250
200
150
100
...
i
E
Q,
0 -;
i
-0
...
.e.

Ill
Q)
!;
C
E
.5
C
0 ;
0 ...
c
g
0 u
Q)
E
.=
LIMITATIONS=
I. Maximum length = 1000 Feet

2. Maximum area = 10 Acres
...

C
Q) . !
(/)
~
li
K
Undeveloped
Good Cover
Undeveloped
Fair Cover
Undeveloped
Poor Cover
Commercial
~ Q) rs..-0 .. - Cl-Ill
0 -0 ,._ C i Q)
~ C
Q) Q)

Tc
5 (min)
6 7
8 9
10 I I
25 30
35 40
::-
E
0 LL
...
0 -
.s
.....
u
....
-
C
0 "ij
...
-
C
B
C
0 u
-
0 Q)
E
I=
---------------------1
ORANGE COUNTY.

HYDROLOGY MANUAL

TIME OF CONCENTRATION

NOMOGRAPH

FOR INITIAL SUBAREA
D-4 Figure D-I 2034
a:
::,
0 :l:
' U)
uJ
:l:
0 z
Regression Equations: I(t)= atb
(I= Intensity in inches/hour, t= duration in minutes)
Return Frequency
(years)
2 5
10 25
50 100
a

5.702

7.870

10.209

11. 995

13.521

15.560
b
-0.574
-0.562
-0.573
-0.566
-0.566
-0.573
RETURN PcRI00
100 YR
50 YR
25 YR
10 YR
5 YR
2 YR

PRECIPITATION DURATION (MIN)

ORANGE COUNTY

HYDROLOGY MANUAL
B-7

MEAN PRECIPITATION

INTENSITIES FOR

NONMOUNTAINOUS AREAS
Figure B-3 2035
OC Hydrology Manual
Section D - Rational Method
Fp is from Section C.6.4 of OC Hydrology Manual (soil type A) I is from OC Hydrology Manual Figure B-3
Drainage Area 1 Drainage Area 1
10-Year Existing 10-Year Proposed
ai 0.62 ai 0.65
ap 0.38 ap 0.35
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.85 C 0.86
I 3.0 in/hr I 2.8 in/hr
A 3.16 acres A 3.16 acres
Q 8.10 cfs Q 7.57 cfs
Drainage Area 2 Drainage Area 2
10-Year Existing 10-Year Proposed
ai 0.11 ai 0.11
ap 0.89 ap 0.89
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.77 C 0.77
I 2.5 in/hr I 2.5 in/hr
A 0.35 acres A 0.35 acres
Q 0.68 cfs Q 0.68 cfs
Drainage Area 3 Drainage Area 3
10-Year Existing 10-Year Proposed
ai 0.08 ai 0.08
ap 0.92 ap 0.92
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.77 C 0.77
I 2.5 in/hr I 2.5 in/hr
A 0.35 acres A 0.35 acres
Q 0.67 cfs Q 0.67 cfs
15 Argonaut
Rational Method Hydrology Calculation
5/19/2026
2036
Drainage Area 4 Drainage Area 4
10-Year Existing 10-Year Proposed
ai 0.13 ai 0.13
ap 0.87 ap 0.87
Fp 0.4 in/hr Fp 0.4 in/hr
C 0.76 C 0.76
I 2.2 in/hr I 2.2 in/hr
A 0.35 acres A 0.35 acres
Q 0.58 cfs Q 0.58 cfs
2037

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2038
2039
Project Number: Sheet of
Project Name:

Test Personnel:

NOISE MEASUREMENT SURVEY
Site Number: Date: Time: From to
Site Location:

Primary Noise Sources:

Measurement Results Observed Noise Sources/Events
dBA Time Noise Source/Event dBA
Leq
Lmax
Lmin
Lpeak
L5
L10
L50
L90
SEL
dBA
Comments:

Equipment:

Settings: A-Weighted Other
Measured Difference:

Slow Fast Windscreen

50.9 61.4

47.1 -

54.7 53.3

49.6 48.2
-
10:58 Airplane
6513.0001
15 Argonaut ISMND
Henry Welch
1 Southeast corner of property. In the greenbelt directly north of driveway entrance. Just west of metal sign pole.
4/21
1 10:51 11:06
Traffic from Glenwood Drive & Aliso Creek Road. HVAC system from lab facility at 7 Argonaut
LXT 2 0.15
✔ ✔ ✔
2 2040
Atmospheric Conditions
Maximum Wind
Velocity (mph)
Average Wind
Velocity (mph) Temperature (F) Relative Humidity (%)
Comments:

Photos Taken
Photo Number Location/Description

9.1 3 67 55
1 Facing North towards
2 Facing South towards
3 Facing West towards
4 Facing East towards
2041
Project Number: Sheet of
Project Name:

Test Personnel:

NOISE MEASUREMENT SURVEY
Site Number: Date: Time: From to
Site Location:

Primary Noise Sources:

Measurement Results Observed Noise Sources/Events
dBA Time Noise Source/Event dBA
Leq
Lmax
Lmin
Lpeak
L5
L10
L50
L90
SEL
dBA
Comments:

Equipment:

Settings: A-Weighted Other
Measured Difference:

Slow Fast Windscreen

51.8 60

48.2 -

54.5 53.2

51.1 50
-
6513.0001
15 Argonaut ISMND
Henry Welch
2 Northeast corner of the project site in the parking lot, east of the existing building. 4/21
1 10:56 11:

Traffic from Glenwood Drive & Aliso Creek Road. HVAC system from lab facility at 7 Argonaut
LXT 2 0.15
✔ ✔ ✔
2 2042
Atmospheric Conditions
Maximum Wind
Velocity (mph)
Average Wind
Velocity (mph) Temperature (F) Relative Humidity (%)
Comments:

Photos Taken
Photo Number Location/Description

9.1 3 67 55
1 Facing North towards parkng space and hillside towards Glenwood Drive 2 Facing South towards Into parking lot of 15 Argonaut
3 Facing West towards towards parking lot of 15 Argonaut 4 Facing East towards planter and neighboring lab facility 2043
Project Number: Sheet of
Project Name:

Test Personnel:

NOISE MEASUREMENT SURVEY
Site Number: Date: Time: From to
Site Location:

Primary Noise Sources:

Measurement Results Observed Noise Sources/Events
dBA Time Noise Source/Event dBA
Leq
Lmax
Lmin
Lpeak
L5
L10
L50
L90
SEL
dBA
Comments:

Equipment:

Settings: A-Weighted Other
Measured Difference:

Slow Fast Windscreen

47.3 81.7

40.6 -

50.4 49.7

46.5 43.2
-
12:53 Airplane
1:01 Man hitting golfballs nearby. Not very loud no difference 6513.0001
15 Argonaut ISMND
Henry Welch
3 Northwest corner of the project site in the parking lot, west of the exiting building. 4/21
1 12:50 1:06
Traffic from Glenwood Drive & Aliso Creek Road. HVAC system from lab facility at 7 Argonaut
LXT 2
✔ ✔ ✔
2 2044
Atmospheric Conditions
Maximum Wind
Velocity (mph)
Average Wind
Velocity (mph) Temperature (F) Relative Humidity (%)
Comments:

Photos Taken
Photo Number Location/Description
7 3.1 68 59
1 Facing North towards hillside and Glenwood Drive
2 Facing South towards staircase and lunch seating area 3 Facing West towards hillside and Aliso Creek Road
4 Facing East towards building and rusted doors
2045
Mobile Construction Activity Noise Calculation
Equipment Description Lmax Lmax Leq
Grader 85 1 40 250 1 0 64.0 60.1 1011928.85
Excavator 85 1 40 300 1 0 61.7 57.7 585606.974
Dozer 85 1 40 300 1 0 61.7 57.7 585606.974
Front End Loader 80 1 40 300 1 0 56.7 52.7 185185.185
Backhoe 80 1 40 300 1 0 56.7 52.7 185185.185
Notes: Lmax[5] 64 Leq 64
[1] Percentage of time activity occurs each hour based on FHWA usage factors [2] Distance assumes one piece of equipment adjacent to project boundary and others at the closest reasonable operating distance away [3] Soft ground terrain between project site and receptor. [4] Shielding due to terrain or structures
[5] Calculated Lmax is the loudest value.

Distance to Receptor (feet)
Time Hourly Leq Leq' 0.1*Leq antiLog
Night 12:00 AM 0.0 10.0 1 10
1:00 AM 0.0 10.0 1 10
2:00 AM 0.0 10.0 1 10
3:00 AM 0.0 10.0 1 10
4:00 AM 0.0 10.0 1 10
5:00 AM 0.0 10.0 1 10
6:00 AM 0.0 10.0 1 10
Day 7:00 AM 0.0 0.0 0 1
250 8:00 AM 64.1 64.1 6.407138102 2553513.17
300 9:00 AM 63.3 63.3 6.327806547 2127191.29
350 10:00 AM 61.3 61.3 6.126966178 1339572.36
400 11:00 AM 59.5 59.5 5.952990337 897408.827
Lunch break 12:00 PM 0.0 0.0 0 1
450 1:00 PM 58.0 58.0 5.799532769 630278.902
500 2:00 PM 56.6 56.6 5.662260298 459473.319
550 3:00 PM 55.4 55.4 5.538082242 345209.105
600 4:00 PM 54.2 54.2 5.42471656 265898.912
5:00 PM 0.0 0.0 0 1
6:00 PM 0.0 0.0 0 1
Evening 7:00 PM 0.0 5.0 0.5 3.16227766
8:00 PM 0.0 5.0 0.5 3.16227766
9:00 PM 0.0 5.0 0.5 3.16227766
Night 10:00 PM 0.0 10.0 1 10
11:00 PM 0.0 10.0 1 10
Sum 8618649.37
Sum/8 1077331.17
Log10(Sum/8) 6.03234923
10*Log10(Sum/8) 60.3234923
8 Hour Average 60
Equipment Description Lmax Lmax Leq
Grader 85 1 40 300 1 0 69.4 57.7 585606.974
Excavator 85 1 40 300 1 0 69.4 57.7 585606.974
Dozer 85 1 40 300 1 0 69.4 57.7 585606.974
Front End Loader 80 1 40 300 1 0 64.4 52.7 185185.185
Backhoe 80 1 40 300 1 0 64.4 52.7 185185.185
Leq 63
Equipment Description Lmax Lmax Leq
Grader 85 1 40 350 1 0 68.1 55.7 368778.736
Excavator 85 1 40 350 1 0 68.1 55.7 368778.736
Dozer 85 1 40 350 1 0 68.1 55.7 368778.736
Front End Loader 80 1 40 350 1 0 63.1 50.7 116618.076
Backhoe 80 1 40 350 1 0 63.1 50.7 116618.076
Leq 61
Notes: *Equipment is measured as
operating across the project site
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Ground
Effect[3]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
8 Hour Average Calculation
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
2046
Equipment Description Lmax Lmax Leq
Grader 85 1 40 400 1 0 66.9 53.9 247052.942
Excavator 85 1 40 400 1 0 66.9 53.9 247052.942
Dozer 85 1 40 400 1 0 66.9 53.9 247052.942
Front End Loader 80 1 40 400 1 0 61.9 48.9 78125
Backhoe 80 1 40 400 1 0 61.9 48.9 78125
Leq 60
Equipment Description Lmax Lmax Leq
Grader 85 1 40 450 1 0 65.9 52.4 173513.178
Excavator 85 1 40 450 1 0 65.9 52.4 173513.178
Dozer 85 1 40 450 1 0 65.9 52.4 173513.178
Front End Loader 80 1 40 450 1 0 60.9 47.4 54869.6845
Backhoe 80 1 40 450 1 0 60.9 47.4 54869.6845
Leq 58
Equipment Description Lmax Lmax Leq
Grader 85 1 40 500 1 0 65.0 51.0 126491.106
Excavator 85 1 40 500 1 0 65.0 51.0 126491.106
Dozer 85 1 40 500 1 0 65.0 51.0 126491.106
Front End Loader 80 1 40 500 1 0 60.0 46.0 40000
Backhoe 80 1 40 500 1 0 60.0 46.0 40000
Leq 57
Equipment Description Lmax Lmax Leq
Grader 85 1 40 550 1 0 64.2 49.8 95034.6404
Excavator 85 1 40 550 1 0 64.2 49.8 95034.6404
Dozer 85 1 40 550 1 0 64.2 49.8 95034.6404
Front End Loader 80 1 40 550 1 0 59.2 44.8 30052.592
Backhoe 80 1 40 550 1 0 59.2 44.8 30052.592
Leq 55
Equipment Description Lmax Lmax Leq
Grader 85 1 40 600 1 0 63.4 48.6 73200.8718
Excavator 85 1 40 600 1 0 63.4 48.6 73200.8718
Dozer 85 1 40 600 1 0 63.4 48.6 73200.8718
Front End Loader 80 1 40 600 1 0 58.4 43.6 23148.1481
Backhoe 80 1 40 600 1 0 58.4 43.6 23148.1481
Leq 54
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Calculated (dBA)
Energy
Usage
factor[1]
Distance to
Receptor [2]
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
2047
Mobile Construction Activity Noise Calculation
Equipment Description Lmax Lmax Leq
Grader 85 1 40 250 1 0 64.0 60.1 1011928.85
Excavator 85 1 40 300 1 0 61.7 57.7 585606.974
Dozer 85 1 40 300 1 0 61.7 57.7 585606.974
Front End Loader 80 1 40 300 1 0 56.7 52.7 185185.185
Backhoe 80 1 40 300 1 0 56.7 52.7 185185.185
Notes: Lmax[5] 64 Leq 64
[1] Percentage of time activity occurs each hour based on FHWA usage factors [2] Distance assumes one piece of equipment adjacent to project boundary and others at the closest reasonable operating distance away [3] Soft ground terrain between project site and receptor. [4] Shielding due to terrain or structures
[5] Calculated Lmax is the loudest value.

Distance to Receptor (feet)
Time Hourly Leq Leq' 0.1*Leq antiLog
Night 12:00 AM 0.0 10.0 1 10
1:00 AM 0.0 10.0 1 10
2:00 AM 0.0 10.0 1 10
3:00 AM 0.0 10.0 1 10
4:00 AM 0.0 10.0 1 10
5:00 AM 0.0 10.0 1 10
6:00 AM 0.0 10.0 1 10
Day 7:00 AM 0.0 0.0 0 1
250 8:00 AM 64.1 64.1 6.407138102 2553513.17
300 9:00 AM 63.3 63.3 6.327806547 2127191.29
350 10:00 AM 61.3 61.3 6.126966178 1339572.36
400 11:00 AM 59.5 59.5 5.952990337 897408.827
Lunch break 12:00 PM 0.0 0.0 0 1
450 1:00 PM 58.0 58.0 5.799532769 630278.902
500 2:00 PM 56.6 56.6 5.662260298 459473.319
550 3:00 PM 55.4 55.4 5.538082242 345209.105
600 4:00 PM 54.2 54.2 5.42471656 265898.912
5:00 PM 0.0 0.0 0 1
6:00 PM 0.0 0.0 0 1
Evening 7:00 PM 0.0 5.0 0.5 3.16227766
8:00 PM 0.0 5.0 0.5 3.16227766
9:00 PM 0.0 5.0 0.5 3.16227766
Night 10:00 PM 0.0 10.0 1 10
11:00 PM 0.0 10.0 1 10
Sum 8618649.37
Sum/8 1077331.17
Log10(Sum/8) 6.03234923
10*Log10(Sum/8) 60.3234923
8 Hour Average 60
Equipment Description Lmax Lmax Leq
Grader 85 1 40 300 1 0 69.4 57.7 585606.974
Excavator 85 1 40 300 1 0 69.4 57.7 585606.974
Dozer 85 1 40 300 1 0 69.4 57.7 585606.974
Front End Loader 80 1 40 300 1 0 64.4 52.7 185185.185
Backhoe 80 1 40 300 1 0 64.4 52.7 185185.185
Leq 63
Equipment Description Lmax Lmax Leq
Grader 85 1 40 350 1 0 68.1 55.7 368778.736
Excavator 85 1 40 350 1 0 68.1 55.7 368778.736
Dozer 85 1 40 350 1 0 68.1 55.7 368778.736
Front End Loader 80 1 40 350 1 0 63.1 50.7 116618.076
Backhoe 80 1 40 350 1 0 63.1 50.7 116618.076
Leq 61
Notes: *Equipment is measured as
operating across the project site
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Ground
Effect[3]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
8 Hour Average Calculation
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
2048
Equipment Description Lmax Lmax Leq
Grader 85 1 40 400 1 0 66.9 53.9 247052.942
Excavator 85 1 40 400 1 0 66.9 53.9 247052.942
Dozer 85 1 40 400 1 0 66.9 53.9 247052.942
Front End Loader 80 1 40 400 1 0 61.9 48.9 78125
Backhoe 80 1 40 400 1 0 61.9 48.9 78125
Leq 60
Equipment Description Lmax Lmax Leq
Grader 85 1 40 450 1 0 65.9 52.4 173513.178
Excavator 85 1 40 450 1 0 65.9 52.4 173513.178
Dozer 85 1 40 450 1 0 65.9 52.4 173513.178
Front End Loader 80 1 40 450 1 0 60.9 47.4 54869.6845
Backhoe 80 1 40 450 1 0 60.9 47.4 54869.6845
Leq 58
Equipment Description Lmax Lmax Leq
Grader 85 1 40 500 1 0 65.0 51.0 126491.106
Excavator 85 1 40 500 1 0 65.0 51.0 126491.106
Dozer 85 1 40 500 1 0 65.0 51.0 126491.106
Front End Loader 80 1 40 500 1 0 60.0 46.0 40000
Backhoe 80 1 40 500 1 0 60.0 46.0 40000
Leq 57
Equipment Description Lmax Lmax Leq
Grader 85 1 40 550 1 0 64.2 49.8 95034.6404
Excavator 85 1 40 550 1 0 64.2 49.8 95034.6404
Dozer 85 1 40 550 1 0 64.2 49.8 95034.6404
Front End Loader 80 1 40 550 1 0 59.2 44.8 30052.592
Backhoe 80 1 40 550 1 0 59.2 44.8 30052.592
Leq 55
Equipment Description Lmax Lmax Leq
Grader 85 1 40 600 1 0 63.4 48.6 73200.8718
Excavator 85 1 40 600 1 0 63.4 48.6 73200.8718
Dozer 85 1 40 600 1 0 63.4 48.6 73200.8718
Front End Loader 80 1 40 600 1 0 58.4 43.6 23148.1481
Backhoe 80 1 40 600 1 0 58.4 43.6 23148.1481
Leq 54
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Energy
Energy
Ground
Effect[3]
Shielding
(dBA)[4]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
Usage
factor[1]
Distance to
Receptor [2]
Calculated (dBA)
Energy
Usage
factor[1]
Distance to
Receptor [2]
Ground
Effect[3]
Shielding
(dBA)[4]
Calculated (dBA)
Receiving residential land use
Reference
(dBA) 50 ft
Quantity
2049
Residential-Grade Mechanical Equipment Noise Calculation Noise Level Calculation Prior to Implementation of Noise Attenuation Requirements Equipment Description Lmax Lmax Leq
Residential grade mechanical ventilation equipment 70 1 80 265 1 0 11.6 10.6 11.606897 Residential grade mechanical ventilation equipment 70 1 80 290 1 0 10.4 9.5 8.8564517 Residential grade mechanical ventilation equipment 70 1 80 315 1 0 9.4 8.4 6.9107008 Residential grade mechanical ventilation equipment 70 1 80 340 1 0 8.4 7.4 5.4956239 Notes: Leq 15
[1] Percentage of time activity occurs each hour
[2] Soft ground terrain between project site and receptor. [3] Shielding due to structural/soundwall shielding
Ground
Effect[2]
Shielding
(dBA)[3]
Calculated (dBA)
Energy
Receiving residential land use
Reference
(dBA) 3 ft
Quantity
Usage
factor[1]
Distance
to
Receptor
2050
FCS
Appendix H:

Public Service Letters
•• • FCS
An ADEC Innovation
2051

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2052
FCS
H.1 - Orange County Fire Authority
•• • FCS
An ADEC Innovation
2053

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2054
Outlook
RE: 15 Argonaut Residential Project- Fire Services
From Letterman, Todd <[email protected]>
Date Thu 4/23/2026 9:04 AM
To Heather Carr <[email protected]>
Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department

1. Please identify which station(s) will provide service to the proposed project's area.

OCFA Fire Station #57 (1.62 mi)

ALISO VIEJO
57 Journey
Aliso Viejo, CA 92656
OCFA Fire Station #22 (1.63 mi)

LAGUNA HILLS/LAGUNA WOODS
24001 Paseo de Valencia
Laguna Woods, CA 92637
OCFA Fire Station #39 (2.38 mi)

NORTH LAGUNA NIGUEL
24241 Avila Rd.

Laguna Niguel, CA 92677

2. Please describe existing staffing levels and assets (department-wide and at any other station(s) that would serve the Project area). Please include a description of number of firefighters, EMT personnel, engines, hook and ladder trucks, etc., and whether this has changed substantially in the last 20 years. What is the target service ratio that the department would like to achieve?
Fire service response from the three closest stations will consist of 4 engines, 1 truck, and 1 battalion chief for a total of 21 all risk personnel. There has been no substantial change in the last 20 years.

3. Please provide the current average response times for emergency calls for service as a whole and whether this has changed substantially in the last 20 years.

Our current OCFA response time is 8: 16 @ the 90th percentile. We do not use averages to calculate response times.

4. Please provide information about the residential and non-residential development fee schedule. What are the current rates?
Through a OCFA Secured Fire Protection Agreement (SFPA), OCFA charges a development impact fee of $600 per residential unit or an equivalent for commercial development square footage may be divided by 1,000 and then multiplied by 0.9 to reach equivalent dwelling units.

These rates are currently being updated.
2055
Paul Whittaker
Division Chief, Strategic Services
Orange County Fire Authority
Mobile: 949.217.4771
In Service of Others!
From: Heather Carr <[email protected]>
Sent: Wednesday, April 22, 2026 3:17 PM
To: [email protected]; Evans, Eric <[email protected]>; Letterman, Todd <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: Re: 15 Argonaut Residential Project - Fire Services Your attachments have been security checked by Mimecast Attachment Protection. Files where no threat or malware was detected are attached.

Hello Orange County Fire Department Staff,
I am following up on my earlier email requesting input on the applicable Service Questions related to the 15 Argonaut Residential Project we have provided in the letter mentioned below, which I have reattached to this email.

If there are any additional details or questions that you may have regarding the proposed project, please feel free to reach me at your earliest convenience.

Best,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
From: Heather Carr
Sent: Tuesday, April 7, 2026 4:50 PM
To: [email protected] <[email protected]>; [email protected] <[email protected]>; [email protected] <[email protected]>
Cc: Regan Del Rosario <[email protected]>
Subject: 15 Argonaut Residential Project - Fire Services Dear Orange County Fire Department Staff,
FirstCarbon Solutions (FCS) is preparing a Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) to identify any potential environmental impacts that would result from implementation of the 15 Argonaut Residential Project in the City of Aliso Viejo, California that requires review under the California Environmental Quality Act (CEQA).

The attached pdf shows the full letter with project description as well as relevant exhibits maps showing the proposed rezoning areas. Inside you will find the Service Questions we have for Fire Services.
2056
We greatly appreciate your expertise and assistance in this matter. Your responses will help us ensure that our analysis is accurate and complete. To ensure a timely completion of our analysis, please provide your response via e-mail no later than Friday, May 1, 2026. If you have any questions, please contact me by email at [email protected].

Thank you again.

Sincerely,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
Linkedln linkedin.com/in/heather-carr-a46813115
PDT/UTC-07:00
•• • FCS
An ADiEC I nno,vati on
Confidentiality Statement
This message (including any attachments) contains confidential information intended for a specific individual and purpose and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. Please consider the environment before printing this e-mail. 2057

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2058
FCS
H.2 - Orange County Sheriff’s Department
•• • FCS
An ADEC Innovation
2059

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2060
Outlook
Re: [EXTERNAL] Re: 15 Argonaut Residential Project- Police/Sheriff Services From Buhr, Ryan V <[email protected]>
Date Wed 4/29/2026 2:23 PM
To Heather Carr <[email protected]>; [email protected] <[email protected]> Cc Regan Del Rosario <[email protected]>
Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department Heather,
Please refer to the responses below:

Service Questions

1. What is the target service ratio that the Sheriff Department would like to achieve? - We utilize a workload-based staffing model. We do not have a population-to-staff ratio in place. Currently, based on our patrol allocation model, we are short 1 Deputy Sheriff in patrol.

2. Please provide the current average response times for emergency calls for service. - The Department's Goal is under 5 minutes for an emergency response. Last month our average was 5:23

3. Please list any existing or planned mutual aid agreements with other agencies. - We are the county's mutual aid agency and partner with 13 contract cities in our area.

4. Please describe concerns related to potential population growth associated with the Proposed Project.

This includes concerns related to response times, staffing, apparatus, stations, etc. Please describe any measures that you would recommend to reduce potential concerns/challenges. - Similar answer to #1 - we are a workload-based model and staff accordingly.

5. Please describe the emergency response or emergency evacuation plans, including but not limited to, emergencies related to seismic and wildfire events, that are in place. Additionally, what emergency operation centers would serve future development within the Sheriff Department's service area in the event of an emergency?
- The City of Aliso Viejo has their own internal emergency response plans. The Orange County Sheriff's Department has a fully staffed Emergency Operations Center:
- httgs://ocsheriff.gov/commands-divisions/investigations-sgecial-ogerations-command/emergency.:
management/hazard-mitigation#docaccess-f5582eae56245e60fe3ef47b2fcd6ea8

6. Do any adopted emergency response plans or emergency evacuation plans need revisions? - The OCSD response plan is constantly evaluated.
2061
Ryan Buhr I Captain
Aliso Viejo Police Services I Chief of Police
12 Journey, Suite 100 I Aliso Viejo I CA I 92656
(O) 949-425-2561 I [email protected]
From: Heather Carr <[email protected]>
Sent: Wednesday, April 22, 2026 3:15 PM
To: [email protected] <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: [EXTERNAL] Re: 15 Argonaut Residential Project - Police/Sheriff Services Hello Orange County Sheriff Department Staff,
I am following up on my earlier email requesting input on the applicable Service Questions related to the 15 Argonaut Residential Project we have provided in the letter mentioned below, which I have reattached to this email.

If there are any additional details or questions that you may have regarding the proposed project, please feel free to reach me at your earliest convenience.

Best,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
From: Heather Carr <[email protected]>
Sent: Tuesday, April 7, 2026 4:59 PM
To: [email protected] <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: 15 Argonaut Residential Project - Police/Sheriff Services Dear Orange County Sheriff Department Staff,
FirstCarbon Solutions (FCS) is preparing a Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) to identify any potential environmental impacts that would result from implementation of the 15 Argonaut Residential Project in the City of Aliso Viejo, California that requires review under the California Environmental Quality Act (CEQA).

The attached pdf shows the full letter with project description as well as relevant exhibits maps showing the proposed rezoning areas. Inside you will find the Service Questions we have for Police/Sheriff Services.
2062
We greatly appreciate your expertise and assistance in this matter. Your responses will help us ensure that our analysis is accurate and complete. To ensure a timely completion of our analysis, please provide your response via e-mail no later than Friday, May 1, 2026. If you have any questions, please contact me by email at [email protected].

Thank you again.

Sincerely,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
Linkedln linkedin.com/in/heather-carr-a46813115
PDT/UTC-07:00
•• • FCS
An ADEC lnno,vation
Confidentiality Statement
This message (including any attachments) contains confidential information intended for a specific individual and purpose and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. Please consider the environment before printing this e-mail.

Confidential Communications: This email and any files or attachments transmitted with it may contain privileged or otherwise confidential information. If you are not the intended recipient, or believe that you may have received this communication in error, please advise the sender via reply email and immediately delete the email you received. I ATTENTION: EXTERNAL EMAIL. USE CAUTION WHEN OPENING ATTACHMENTS OR CLICKING ON LINKS. REPORT SUSPICIOUS MESSAGES TO THE IT HELP DESK. 2063

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2064
FCS
H.3 - Aliso Viejo Parks Services
•• • FCS
An ADEC Innovation
2065

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2066
Outlook
Re: 15 Argonaut Residential Project- Park Services
From So Kim <[email protected]>
Date Wed 4/22/2026 3:45 PM
To Heather Carr <[email protected]>
Cc Regan Del Rosario <[email protected]>; Lizzy Mendoza <[email protected]>; Recreation Department <[email protected]>; Shaun Pelletier <[email protected]> Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department Hi Heather,
Please see responses to your service questions.

1. Please identify the current parks and recreational facility centers of the Aliso Viejo Recreation & Community Services. Please describe the existing conditions of these parks and recreational facility centers. The City oversees the operations at the Aliso Viejo Ranch, Iglesia Community Center, the Aliso Viejo Aguatic Center, and the Aliso Viejo Center. The City owns and manages Iglesia Park and Vista Park. All these facilities and parks are in great condition.

2. Please identify current park and recreational facility center usage for the City. Aliso ViejQ Ranch hosts all rental and recreational programs for the City. This facility is managed by the Recreation & Community Services Department. The Iglesia Community Center and Park is a space managed by the Boys & Girls Club of Capistrano Valley as an after-school program for youth in the community. The Aliso Viejo Aguatic Center is managed by Premier Aquatics for swimming lessons. The Aliso Viejo Center is managed by Wedgewood Weddings as a banquet center.

3. Please provide an estimate of the current park acres per 1,000 residents and the target ratio that the Aliso Viejo Recreation & Community Services would like to achieve. The City owns and manages Vista Park and Iglesia Park. The total acreage of these two parks is 7.4 acres. The Master Homeowners Association is responsible for 21 parks and 600 acres of landscape. The City's Conservation/Ogen Sgace Element states that as of 2003, the City had a ratio of 5.37 acres of parkland per 1,000 residents. It further states that the standard is 5 acres per 1,000 residents and that new development shall provide fees or dedicate land per the City's code.

4. Please describe concerns related to potential population growth associated with the proposed project. Please describe any measures that you would recommend to reduce potential concerns/challenges. The proposed project may have several concerns related to population rise, such as, potential increase to traffic/congestion, strain on infrastructure, change in character of the immediate and larger area, and other environmental impacts, etc. Examples of mitigation measures may include some type of improvement or upgrades to traffic management, infrastructure, police/fire services etc.

So Kim I Director of Community Development
ALISO VIEJO 1.1'-'l lift l1up1rtd
City of Aliso Viejo
12 Journey, Suite 100
Aliso Viejo, CA 92656
T: 949-425-2527
avcity.org
2067
From: Heather Carr <[email protected]>
Sent: Wednesday, April 22, 2026 3:12 PM
To: Lizzy Mendoza <[email protected]>; Recreation Department <[email protected]>; So Kim <[email protected]>; Shaun Pelletier <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: Re: 15 Argonaut Residential Project - Park Services Some people who received this message don't often get email from [email protected]. Learn why this is imf;!ortant Hello Ms. Mendoza,
I am following up on my earlier email requesting input from the Aliso Viejo Recreation & Community Services on the applicable Service Questions related to the 15 Argonaut Residential Project we have provided in the letter mentioned below, which I have reattached to this email.

If there are any additional details or questions that you may have regarding the proposed project, please feel free to reach me at your earliest convenience.

Best,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
From: Heather Carr
Sent: Tuesday, April 7, 2026 4:57 PM
To: [email protected] <[email protected]>; [email protected] <[email protected]>; [email protected] <[email protected]>; [email protected] <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: 15 Argonaut Residential Project - Park Services Dear Recreation and Community Services Manager Lizzy Mendoza, FirstCarbon Solutions (FCS) is preparing a Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) to identify any potential environmental impacts that would result from implementation of the 15 Argonaut Residential Project in the City of Aliso Viejo, California that requires review under the California Environmental Quality Act (CEQA).

We greatly appreciate your expertise and assistance in this matter. Your responses will help us ensure that our analysis is accurate and complete. To ensure a timely completion of our analysis, please provide your response via e-mail no later than Friday, May 1, 2026. If you have any questions, please contact me by email at [email protected].

Thank you again.
2068
Sincerely,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
Linkedln linkedin.com/in/heather-carr-a46813115
PDT/UTC-07:00
•• • FCS
An ADiEC I nno,vati on
Confidentiality Statement
This message (including any attachments) contains confidential information intended for a specific individual and purpose and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. Please consider the environment before printing this e-mail.

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2070
FCS
H.4 - Capistrano Unified School District
•• • FCS
An ADEC Innovation
2071

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2072
Outlook
RE: 15 Argonaut Residential Project - School Services
From Hampton, Clark D.<[email protected]>
Date Wed 4/15/2026 9:38 AM
To Heather Carr <[email protected]>; Mahindrakar, Manoj A. <[email protected]>; Robles, Emma M. <[email protected]>; Duarte, George <[email protected]> Cc Regan Del Rosario <[email protected]>
Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department Hi Heather
The numbers provided are the number of students the project is expected to generate. All schools that serve the development can accommodate those students. However, the developer still needs to pay Level 1 school developer fees when filing for a permit.

Clark
I Clark Hampton I Deputy Superintendent, Business and Support Services I I Capistrano Unified School District I 33122 Valle Road, San Juan Capistrano, CA 92675 I (949) 234-9211 "A school isn't only a building. It's an expression of beliefs and attitudes about ourselves and the generations of young people for whom it is planned. In its silent language of space, scale and shape, the structure stands for what we are, what we think of ourselves and what we believe we can become."
From: Heather Carr <[email protected]>
Sent: Wednesday, April 15, 2026 9:34 AM
To: Hampton, Clark D. <[email protected]>; Mahindrakar, Manoj A. <[email protected]>; Robles, Emma M.<[email protected]>; Duarte, George <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: Re: 15 Argonaut Residential Project - School Services Hi Mr. Hampton,
Thank you for your prompt response!
Can you please provide clarification for your answer to number 2? Specifically, do the numbers mentioned reflect an anticipated increase in enrollment within the district due to the proposed 15 Argonaut project, or do these numbers represent the students needed to achieve the district's planned enrollment targets? Please let us know and please provide/confirm both the anticipated increase due to the proposed project and the planned enrollment targets if you have those numbers available. This information is incredibly helpful for our evaluation and your insight is appreciated.

Thank you,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
2073
From: Hampton, Clark D.<[email protected]>
Sent: Tuesday, April 14, 2026 7:15 PM
To: Heather Carr <[email protected]>; Mahindrakar, Manoj A.<[email protected]>; Robles, Emma M. <[email protected]>; Duarte, George <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: RE: 15 Argonaut Residential Project - School Services Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department Good morning Heather
See answers to your questions below:

Service Questions

1. Please identify the Capistrano Unified School District's (CUSD) area of enrollment.

The three schools (shown on attached map) serving the development (circled on attached map) are:

Oak Grove Elementary School
Aliso Viejo Middle School
Aliso Niguel High School

2. Please provide an estimate of the current standard student generation factors for elementary, middle, and high school students used by the CUSD and the target student enrollment that CUSD would like to achieve.

TK-5 13 students
6-8 5 students
9-12 5 students

3. Please describe concerns related to potential population growth associated with the Housing Development Project. Please describe any measures that you would recommend to reduce potential concerns/challenges.

The District does not have any concerns with the numbers of students generated by this development.

Developer would be expected to pay Level 1 developer fees for this project. 2074
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I Capistrano Unified School District I 33122 Valle Road, San Juan Capistrano, CA 92675 I (949) 234-9211 Stater " Bros.

II Mimi's Cafe
"A school isn't only a building. It's an expression of beliefs and attitudes about ourselves and the generations of young people for whom it is planned. In its silent language of space, scale and shape, the structure stands for what we are, what we think of ourselves and what we believe we can become."
From: Heather Carr <[email protected]>
Sent: Tuesday, April 7, 2026 5:44 PM
II
To: Hampton, Clark D.<[email protected]>; Mahindrakar, Manoj A.<[email protected]>; Robles, Emma M.<[email protected]>; Duarte, George <[email protected]> Cc: Regan Del Rosario <[email protected]>
Subject: 15 Argonaut Residential Project - School Services Dear Deputy Superintendent Clark Hampton and District Principals:
2075
FirstCarbon Solutions (FCS) is preparing a Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) to identify any potential environmental impacts that would result from implementation of the 15 Argonaut Residential Project in the City of Aliso Viejo, California that requires review under the California Environmental Quality Act (CEQA).

The attached pdf shows the full letter with project description as well as relevant exhibits maps showing the proposed rezoning areas. Inside you will find the Service Questions we have for School Services. Although the letter is directed to Superintindent Hampton, we have included the principals of schools that would be servicing the project in this email in order to request any additional information that they may be able to provide on student generation factors, enrollment, and anything else they would be able to share regarding potential impacts on school services.

Thank you again.

Sincerely,
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
Linkedln linkedin.com/in/heather-carr-a46813115
PDT/UTC-07:00
•• • FCS
An ADEC Innovation
Confidentiality Statement
This message (including any attachments) contains confidential information intended for a specific individual and purpose and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. Please consider the environment before printing this e-mail.
2076
FCS
H.5 - Orange County Public Libraries
•• • FCS
An ADEC Innovation
2077

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2078

DYLAN WRIGHT

DIRECTOR

OC COMMUNITY RESOURCES

CYMANTHA ATKINSON

ASSISTANT DIRECTOR

OC COMMUNITY RESOURCES

JOANNE VEEDOR

DIRECTOR

ADMINISTRATIVE SERVICES

MONICA SCHMIDT

DIRECTOR

QC ANIMAL CARE

JULIA BIDWELL

DIRECTOR

QC HOUSING & COMMUNITY

DEVELOPMENT

RENEE RAMIREZ

DIRECTOR

QC COMMUNITY SERVICES

PAM PASSOW

DIRECTOR

DC PARKS

JULIE QUILLMAN

COUNTY LIBRARIAN

QC PUBLIC LIBRARIES
C~-0.0,-~
Public Libraries ~---.-.
1501 E. ST. ANDREW PLACE
SANTA ANA, CA 92705-4930
PHONE: 714.566.3000
CCommunity Resources
April 16, 2026
Heather Carr
Environmental Services Analyst I
FCS -An ADEC Innovation
15 Argonaut Residential Project
Library Services Questions:

1. Please identify the Aliso Viejo Library's current library membership for the City.

Aliso Viejo specifically does not have a "membership." OC Public Libraries (OCPL) operates as a countywide system of 29 branches, and every patron has full access to all OCPL locations regardless of where they register. Therefore, the Aliso Viejo Library does not maintain a branch-specific membership count.

For reporting purposes, and consistent with OCPL's systemwide service model, the Aliso Viejo Library's usage is measured by annual visitation. In calendar year 2023, the branch recorded 140,931 visitors, with an average daily attendance of approximately 470 people. These figures represent the most current pre-closure statistics available, as the branch closed in early 2024 for a tenant enhancement project and reopened in March 2026.

2. Please provide an estimate of the current Aliso Viejo Library services demand and the target ratio that the Aliso Viejo Library would like to achieve.

Usage in 2023 represented a high-traffic community branch, recording 140,931 visitors with an average of 470 daily attendees. These figures reflect a consistent baseline demand for library services at this location prior to closure.

Upon reopening, demand is expected to increase due to anticipated improvements, including quiet study rooms, expanded electrical access, additional seating, and a new program room designed to support expanded programming for all ages. These enhancements historically correlate with notable increases in visitor usage in similar OCPL remodel projects.

3. Please describe concerns related to potential population growth associated with the project. Please describe any measures that you would recommend to reduce potential concerns/challenges.

The proposed project includes 58 three-story townhomes, and using OCPL's standard assumption of three residents per unit, the development is anticipated to introduce approximately 174 new residents into the surrounding area. The site is located approximately 2.3 miles from the Aliso Viejo Library, an increase of this scale is not expected to create a significant impact on library services. 2079
OCPL would recommend continued coordination with the City if future development proposals in the vicinity indicate additional population increases beyond current projections.

Sincerely,
uillman, County Librarian
2080
Outlook
RE: 15 Argonaut Residential Project - Library Services
From Oakley, Julie <[email protected]>
Date Thu 4/16/2026 4:35 PM
To Heather Carr <[email protected]>
Cc Regan Del Rosario <[email protected]>
® 1 attachment (422 KB)
15 Argonaut Project OCPL Response 4-2026.pdf;
Caution: This is an external email and may contain suspicious subject or content. Please take care when clicking links or opening attachments. When in doubt, please contact your IT Department Hello Heather
Please see the attached OC Public Libraries Response to the 15 Argonaut Project.

Thank you
ecc
Public Libraries Open Doors. Fn:e Aa:ess. Community.

Julie A. Oakley
Library Administration
1501 E. St. Andrew Place, Santa Ana, CA 92705
Office: 714-566-30241 Cell: 714-788-7312
From: Heather Carr <[email protected]>
Sent: Tuesday, April 7, 2026 4:54 PM
To: Oakley, Julie <[email protected]>
Cc: Regan Del Rosario <[email protected]>
Subject: 15 Argonaut Residential Project - Library Services Attention: This email originated from outside the County of Orange. Use caution when opening attachments or links.

Dear Aliso Viejo Library Staff,
FirstCarbon Solutions (FCS) is preparing a Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) to identify any potential environmental impacts that would result from implementation of the 15 Argonaut Residential Project in the City of Aliso Viejo, California that requires review under the California Environmental Quality Act (CEQA). 2081
The attached pdf shows the full letter with project description as well as relevant exhibits maps showing the proposed rezoning areas. Inside you will find the Service Questions we have for Library Services.

Thank you again.

Sincerely
Heather Carr
Environmental Services Analyst I
Phone 714-887-7867
Linkedln linkedin.com/in/heather-carr-a46813115
PDT/UTC-07:00
•• • FCS
An ADiEC I nno,vati on
Confidentiality Statement
This message (including any attachments) contains confidential information intended for a specific individual and purpose and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. Please consider the environment before printing this e-mail. 2082
Presidio at Pacific Park Residential Development
Mitigation Monitoring and Reporting Program
City of Aliso Viejo, Orange County, California
PREPARED FOR:

City of Aliso Viejo
12 Journey, Suite 100
Aliso Viejo, CA 92656
949.425.2525
Contact: So Kim, Community Development Director
PREPARED BY:

FirstCarbon Solutions
250 Commerce, Suite 210
Irvine, CA 92602
714.508.4100
Contact: Cecilia So, Project Director
Tsui Li, Project Manager
September 28, 2026
2083
Presidio at Pacific Park Residential Development
Mitigation Monitoring and Reporting Program
FCS 1

PREFACE
Section 21081.6 of the California Environmental Quality Act (CEQA) and CEQA Guidelines Section 15097 require a Lead Agency to adopt a Mitigation Monitoring and Reporting Program (MMRP) whenever it adopts a Mitigated Negative Declaration (MND) in conjunction with a project approval.

The purpose of the MMRP is to ensure compliance with the mitigation measures occurs during project implementation.

The Draft IS/MND prepared for the proposed Presidio at Pacific Park Residential Development (proposed project) concluded that project implementation could result in potentially significant effects on the environment, and mitigation measures were incorporated into the proposed project or are required as a condition of project approval that reduce these potential impacts to a less than significant level. This MMRP documents how and when the mitigation measures adopted by the Lead Agency will be implemented and confirms that potential environmental impacts are reduced to less than significant levels as identified in the Draft IS/MND.

This document does not discuss those subjects that the environmental analysis demonstrates would result in less than significant impacts and for which no mitigation was proposed or necessary. 2084

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 3
Table 1: Presidio at Pacific Park Residential Development Mitigation Monitoring and Reporting Program Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial

2.4 Biological Resources
MM BIO-1a: Nesting Bird Pre-construction Surveys
If ground-disturbing or vegetation-removing construction activities or tree removal is proposed during the breeding/nesting season for migratory birds (February 1 through September 15), a qualified Biologist shall conduct pre-construction surveys for special-status birds and other migratory birds within the construction area, including a 300-foot survey buffer (where accessible), no more than 3 days prior to the start of ground-disturbing activities in the construction area.

Submittal to the City of
pre-construction survey
reports for nesting birds
conducted by a
qualified Biologist
Within 3 days prior to
the initiation of
construction
City of Aliso Viejo
Planning Department
MM BIO-1b: Avoidance of Active Avian Nests
If an active nest (i.e., occupied by eggs or fledglings) is located during pre-construction surveys or at any point during the construction phase of the proposed project, the City of Aliso Viejo shall be notified regarding the status of the nest. Furthermore, construction activities shall be restricted as necessary to avoid disturbance of the nest until the eggs or fledglings no longer are in the nest or a qualified Biologist deems disturbance potential to be minimal. Restrictions may include establishment of exclusion zones (no ingress of personnel or equipment at a minimum radius of 300 feet around an active raptor nest and a 50-foot radius around an active migratory bird nest) or alteration of the construction schedule.

Submittal of reports
documenting
establishment of
avoidance buffer by a
qualified Biologist (if
active nests are found),
monitoring and
maintenance of the
restrictions under the
supervision of a
qualified Biologist, final
removal of buffers, and
documentation that
applicable requirements
During preconstruction surveys
or at any point during
construction
City of Aliso Viejo
Planning Department
2085

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 4
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
have been implemented
before grounddisturbing activities
occur within affected
areas.

2.5 Cultural Resources
MM CUL-1: Worker Environmental Awareness Program
Prior to the initiation of construction activities, all construction personnel conducting ground disturbance at the site shall be provided a Worker Environmental Awareness Program (WEAP) cultural resources “tailgate” training. The training shall include visual aids, a discussion of applicable laws and statutes relating to archaeological resources, types of resources that may be found within the project site, and procedures to be followed in the event such resources are encountered. The training shall be conducted by an Archaeologist who meets the Secretary of the Interior’s Professional Qualification Standards for archaeology.

Verify documentation of
WEAP training
materials and employee
attendance. Submission
to the City of WEAP
attendance logs and
training date(s) to City
Prior to initiation of
construction activities
City of Aliso Viejo
Planning Department
An Archaeologist who meets the Secretary of the Interior’s Professional Qualification Standards for archaeology shall conduct an updated survey of the site following demolition and exposure of native soils and prior to any project-related trenching or grading to check for the inadvertent exposure of cultural materials.

Submit to the City
documentation of site
survey
Following demolition
and exposure of
native soils and prior
to trenching or
grading
City of Aliso Viejo
Planning Department
This shall be followed by archaeological monitoring during the grading and trenching phase of the proposed project. At the completion of these phases, archaeological monitoring shall be reduced to periodic “spot checks.” In the event exposed soils indicate cultural materials may be present, this may be followed by Provide documentation
to the City
demonstrating
implementation of
archaeological
During grading and
trenching phases,
after trenching. In the
event of inadvertent
City of Aliso Viejo
Planning Department
2086

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 5
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
regular or full-time archaeological monitoring as determined by the Archaeologist.
monitoring and periodic
“spot checks” after
trenching. Submit
documentation of
archaeological
monitoring (if cultural
materials are found).
discovery of cultural
resources
MM CUL-2: Inadvertent Discovery of Buried Archaeological Resources In the event that buried archaeological resources are discovered during construction, operations shall stop within a 100-foot radius of the find and an Archaeologist who meets the Secretary of Interior’s Professional Qualification Standards for archaeology shall be consulted to determine whether the resource requires further study. The qualified Archaeologist shall make recommendations to the Lead Agency on the measures that shall be implemented to protect the discovered resources, including but not limited to excavation of the finds and evaluation of the finds in accordance with Section 15064.5 of the CEQA Guidelines. Potentially significant cultural resources consist of but are not limited to stone, bone, fossils, wood, or shell artifacts or features, including hearths, structural remains, or historic dumpsites. Any previously undiscovered resources found during construction within the project area shall be recorded on appropriate California Department of Parks and Recreation (DPR) forms and evaluated for significance in terms of CEQA criteria. If the resources are determined to be unique historic resources as defined under Section 15064.5 of the CEQA Guidelines, mitigation measures shall be identified by the monitor and recommended to the Lead Agency. Appropriate mitigation measures for significant resources Submittal and review of
recommendations, and
recordation of
previously
undiscovered
archaeological
resources on
appropriate DPR forms
In the event of
inadvertent discovery
of buried
archaeological
resources during
construction, prior to
resuming operations
City of Aliso Viejo
Planning Department
2087

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 6
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
could include avoidance or capping, incorporation of the site in green space, parks, or open space, or data recovery excavations of the finds. The Lead Agency, along with other relevant or Tribal officials, shall be contacted upon the discovery of cultural resources to begin coordination on the disposition of the find(s).

Treatment of any significant cultural resources shall be undertaken with the approval of the Lead Agency. No further grading shall occur in the area of the discovery until the Lead Agency approves the measures to protect these resources. Upon coordination with the Lead Agency, any archaeological artifacts recovered shall be donated to an appropriate Tribal custodian or a qualified scientific institution where they would be afforded applicable cultural resources laws and guidelines.

MM CUL-3: Accidental Discovery or Recognition of Any Human Remains In the event of the accidental discovery or recognition of any human remains, CEQA Guidelines Section 15064.5, Health and Safety Code Section 7050.5, and Public Resources Code Section 5097.94 and Section 5097.98 shall be followed. If during the course of project construction, there is accidental discovery or recognition of any human remains, the following steps shall be taken:

1. There shall be no further excavation or disturbance of the site where human remains are discovered and/or any
nearby area reasonably suspected to overlie adjacent
human remains until the County Coroner is contacted to
determine whether the remains are Native American and
if an investigation of the cause of death is required.

Submission to the City
of documentation
demonstrating the
Orange County Sheriff’s
Coroner has been
contacted.

In the event of the
accidental discovery
or recognition of any
human remains
during the course of
project development
City of Aliso Viejo
Planning Department
If the Coroner determines the remains to be Native
American, the Coroner shall contact the Native American If the remains are
determined to be of
Within 24 hours of
determining
City of Aliso Viejo
Planning Department
2088

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 7
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
Heritage Commission (NAHC) within 24 hours, and the
NAHC shall identify the person or persons it believes to be the Most Likely Descendant (MLD) of the deceased
Native American. The MLD may make recommendations
to the landowner or the person responsible for the
excavation work within 48 hours, for means of treating or disposing of, with appropriate dignity, the human remains, and any associated grave goods as provided in Public
Resource Code Section 5097.98.

Native American origin,
confirm the MLD and
NAHC have been
contacted, and
submit documentation
of coordination between
County Coroner and
NAHC.

If human remains are
uncovered, confirm
compliance with Public
Resources Code
Section 5097.98.
discovered human
remains to be Native
American

2. Where the following conditions occur, the landowner or his or her authorized representative shall rebury the Native American human remains and associated grave goods with appropriate dignity either in accordance with the recommendations of the MLD or on the project site in a location not subject to further subsurface disturbance:
• The NAHC is unable to identify an MLD or the MLD failed to make a recommendation within 48 hours after being notified by the commission.
• The descendant identified fails to make a recommendation. • The landowner or his authorized representative rejects the recommendation of the descendant, and mediation by the
NAHC fails to provide measures acceptable to the landowner.

Submit written evidence
of treatment and
disposition of remains
consistent with
applicable regulations.

Prior to resuming
construction activities
City of Aliso Viejo
Planning Department
2089

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 8
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial

2.7 Geology and Soils
COA GEO-1a: Soil Engineering and Engineering Geology Recommendations In accordance with Municipal Code 13.08.170, Soil Engineering and Engineering Geology Reports, a soil engineering and engineering geology report shall be required for grading projects unless otherwise waived by the building official. The reports shall include information appropriate for the site including any information required by the building official. Recommendations included in the reports and approved by the building official shall be incorporated in the grading plans or specifications.

Accordingly, prior to issuance of grading permit, the project applicant shall provide grading plans or specifications that include all recommendations from the proposed project’s September 26, 2025 Geotechnical Investigation prepared by Alta California Geotechnical, Inc., or from the latest geotechnical study for the proposed project.

Submission of soil
engineering and
engineering geology
report and inclusion in
project plans; site
inspection; submission
of plans
Prior to the
issuance of a
grading permit;
during and
following project
construction
City of Aliso Viejo
Planning
Department
COA GEO-1b: Grading Activities adjacent to Western and Northern Slopes Prior to and during grading, all grading activities adjacent to the existing slopes along the western and northern boundaries of the site shall be observed by a licensed California Geotechnical Engineer or Certified Engineering Geologist, consistent with the requirements of Aliso Viejo Municipal Code Chapter 13.08 (Grading and Excavation Code).

Provide letter of
retention from licensed
California
Geotechnical Engineer
or Certified
Engineering Geologist
confirming grading
observations
Prior to the
issuance of a
grading permit
City of Aliso Viejo
Planning
Department
2090

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 9
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
If geologic or geotechnical conditions associated with slope instability are encountered that differ from those described in the approved Geotechnical Investigation prepared by Alta California Geotechnical, Inc. (September 26, 2025), the project Geotechnical Consultant shall evaluate such conditions and prepare
supplemental geotechnical recommendations, as necessary, in accordance with the California Building Code and California Geological Survey Special Publication 117A.

Provide
supplementation
geotechnical
recommendations for
City review and
approval.

During construction City of Aliso Viejo
Planning
Department
Any supplemental recommendations or corrective measures shall be incorporated into the grading or construction plans and shall be subject to review and approval by the City Engineer prior to continuation of grading in the affected area, consistent with the Aliso Viejo Municipal Code.

Provide updated
grading or construction
plans detailing any
supplemental
recommendations or
corrective measures
During construction City of Aliso Viejo
Planning
Department
MM GEO-1: Paleontological Resources Worker Environmental Awareness Program The project applicant shall enlist a qualified Paleontologist (meeting the standards of the Society of Vertebrate Paleontology [SVP]) to prepare a Worker Environmental Awareness Program (WEAP) presentation for construction personnel. It will include information on paleontological resources, laws protecting them, types of fossils that could occur at the project site, and protocol for unanticipated discoveries.

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 10
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
In the event that fossils are discovered during construction, excavations within 50 feet of the find shall be temporarily halted or diverted. The contractor shall notify the qualified Paleontologist to examine the discovery. The qualified Paleontologist shall document the discovery as needed in accordance with SVP standards, evaluate the potential resource, and assess the significance of the find under the criteria set forth in CEQA Guidelines Section 15064.5. Based on the significance of the find, the qualified Paleontologist shall determine procedures to be followed before construction is allowed to resume at the location of the find. If, in consultation with the qualified Paleontologist, it is determined that avoidance is not feasible, the qualified Paleontologist shall prepare a Paleontological Resources Impact Mitigation Program (PRIMP) to outline salvage and recovery procedures. If deemed necessary by the qualified Paleontologist, the PRIMP shall include construction monitoring requirements as well. The PRIMP shall be submitted to the City for review and approval, and the approved plan shall be implemented.

If paleontological
resources are
discovered, confirm all
work within 50 feet has
been halted, and
confirm a qualified
Paleontologist has
assessed the find.

Submittal of PRIMP to
City for approval, and
confirmation of
implementation of the
approved plans.

In the event that
fossils are
discovered during
construction
City of Aliso Viejo
Planning Department
2092

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 11
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial

2.9 Hazardous Waste and Materials
MM HAZ-1: Implementation of Asbestos-containing Material, Lead-based Paint, and Petromat Surveys Prior to Site Demolition Activities Prior to the issuance of demolition permits, the proposed project shall retain a Qualified Environmental Professional to conduct asbestos-containing material (ACM), lead-based paint (LBP), and Petromat surveys. If ACM or LBP are identified in existing building materials or if asbestos is identified within any Petromat that is part of the existing parking lot, proper removal and disposal of the materials in accordance with applicable local, regional, State, and federal regulations would be required. In addition, the developer shall implement all appropriate engineering controls, work practices, and notification procedures to prevent exposure of workers and the public and shall prepare and submit all necessary compliance documentation to the City.

Submittal and review of
ACM, LBP, and
Petromat survey reports
and, if applicable,
documentation of
proper removal and
disposal, engineering
controls, notifications,
and regulatory
compliance.

Prior to issuance of
demolition permits
and prior to
demolition activities;
during removal and
disposal if hazardous
materials are
identified.

City of Aliso Viejo
Planning Department

2.18 Tribal Cultural Resources
MM TCR-1: Retention of Qualified Archaeologist and Worker Training Prior to the issuance of a grading permit by the City of Aliso Viejo, evidence shall be provided to the City that a qualified archaeologist meeting the Secretary of the Interior’s Standards for professional archaeology (U.S. Secretary of the Interior 2008) has been retained by the Applicant to conduct any required training, evaluation, or treatment of archaeological resources that might be encountered during implementation of the project.

As part of this, prior to the start of grading, the qualified archaeologist shall conduct cultural resources sensitivity training for all construction personnel. Construction personnel must be Submittal of evidence
that a qualified
archaeologist has been
retained; verification of
cultural resources
sensitivity training
materials and
construction personnel
attendance records.

Prior to issuance of a
grading permit and
prior to the start of
grading
City of Aliso Viejo
Planning
Department
2093

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 12
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
informed of the types of archaeological resources that may be encountered (both prehistoric and historical), and of the proper procedures to be enacted in the event of an inadvertent discovery of archaeological resources or human remains. The Applicant must ensure that construction personnel are made available for and attend the training and retain documentation demonstrating attendance. This documentation shall be made available to the City upon request.

MM TCR-2: Native American Monitoring
A Native American monitor from or approved by the project's consulting Tribes (Juaneño Band of Mission Indians Acjachemen Nation – 84A and Juaneño Band of Mission Indians Acjachemen Nation – Belardes) shall be present during all earth-moving construction activities. The Native American monitor shall be given the opportunity to participate in the cultural resource sensitivity training described in the preceding condition of approval. At least 30 days prior to issuance of grading permits by the City for the project site and any off-site improvements, a Native American Monitoring Agreement (Monitoring Agreement) shall be developed between the Applicant and the consulting party. The Monitoring Agreement shall pertain to prehistoric archaeological resources and Tribal Cultural Resources, respectively, and shall identify any monitoring requirements and treatment of cultural resources to meet the requirements of the Tribal representative. The Monitoring Agreement shall also address communication protocols in the event of an unanticipated discovery of cultural materials, and the roles, responsibilities, and authorities of the Native American Monitor. The Monitoring Agreement shall also detail the protocols for treatment and final disposition of any Native American cultural Submit documentation
that a Native American
monitor has been
retained. Submittal and
review of the executed
Native American
Monitoring Agreement;
review of monitoring
logs, documentation
confirming Native
American monitoring
during earth-moving
activities, and
documentation of
compliance with the
Monitoring Agreement,
State Health and Safety
Code Section 7050.5,
and Public Resources
At least 30 days prior
to issuance of
grading permits;
during all earthmoving construction
activities
City of Aliso Viejo
Planning
Department
2094

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 13
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
resources, sacred sites, and human remains discovered on the site that the Native American Monitor shall implement in consultation and coordination with the Native American Most Likely
Descendant, as identified by the NAHC. In accordance with the condition of approval below, discovery and treatment of human remains shall comply with State Health and Safety Code Section 7050.5 and Public Resources Code (PRC) Section 5097.98.

Code (PRC) Section
5097.98.

MM TCR-3: Archaeological Resource and/or Tribal Cultural Resource Discovery and Treatment In the event of the unanticipated discovery of archaeological or other cultural resources, whether discovered through Native American monitoring or not, all work activities in the area (within approximately 100 feet of the discovery) shall be halted or redirected until the discovery can be evaluated by a qualified archaeologist. Construction shall not resume until a qualified archaeologist has conferred with the City and, in the case of prehistoric archaeological resources and tribal cultural resources, the Native American monitor, on the significance of the resource. If it is determined that the discovered archaeological resource and/or tribal cultural resource is significant, avoidance and preservation in place shall be the preferred manner of mitigation, pursuant to PRC Section 21083.2(b) and Section 21084.3. Preservation in place may be accomplished by, but is not limited to, avoidance, incorporating the resource into open space, capping, or deeding the site into a permanent conservation easement. In the event that preservation in place is demonstrated to be infeasible and data recovery through excavation is the only feasible mitigation available, a Treatment Plan shall be prepared and implemented by a qualified archaeologist, in consultation with the City, that provides for the adequate recovery of the scientifically consequential If archaeological or
cultural resources are
discovered, confirm all
work within 100 feet
has been halted and a
qualified archaeologist
has been retained;
review discovery
documentation,
consultation records,
resource evaluation,
and, if required, an
approved Treatment
Plan; field verification
that work did not
resume until authorized.

Upon discovery of
archaeological or
tribal cultural
resources during
construction and
prior to resuming
work in the discovery
area
City of Aliso Viejo
Planning
Department
2095

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 14
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
information contained in the archaeological resource or cultural information in the event of a tribal cultural resource. The City and Applicant shall also consult with appropriate Native American representatives in determining treatment for prehistoric or Native American resources to ensure cultural values ascribed to the resources, beyond those that are scientifically important, are considered. Any evaluation and treatment shall be supervised by an individual or individuals that meet the Secretary of the Interior’s Professional Qualification Standards.

MM TCR-4: Treatment of Human Remains
In accordance with California Health and Safety Code Section 7050.5, if human remains are found, the Orange County Sheriff’s Coroner shall be immediately notified of the discovery. No further excavation or disturbance of the site or any nearby area reasonably suspected to overlie adjacent remains (100 feet or as determined by the project archaeologist) shall occur until the procedures set forth in this measure have been implemented. If the County Coroner determines that the remains are, or are believed to be, Native American, the Coroner shall notify the Native American Heritage Commission (NAHC) within 24 hours. In accordance with California PRC Section 5097.98, the NAHC must immediately notify those persons it believes to be the Most Likely Descendant (MLD) from the deceased Native American. The MLD shall
complete their inspection within 48 hours of being granted access to the site. The designated Native American representative would then determine, in consultation with the property owner, the disposition of the human remains.

Submit documentation
of coordination between
Orange County Sheriff’s
Coroner and NAHC;
confirm implementation
of the specified
procedures
Within 24 hours of
determining
discovered human
remains to be Native
American
City of Aliso Viejo
Planning
Department
2096

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 15
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM TCR-5: Native American Monitoring
The project applicant shall retain a Native American Monitor from or approved by the project's consulting Tribes (Juaneño Band of Mission Indians Acjachemen Nation – 84A and Juaneño Band of Mission Indians Acjachemen Nation – Belardes).
(a) The monitor shall be retained prior to the
commencement of any “ground- disturbing
activity” for the subject project at all project
locations (i.e., both on-site and any off-site
locations that are included in the project
description/definition and/or required in
connection with the project, such as public
improvement work). “Ground-disturbing
activity” shall include, but is not limited to,
demolition, pavement removal, potholing,
auguring, grubbing, tree removal, boring,
grading, excavation, drilling, and trenching.
(b) A copy of the executed monitoring
agreement shall be submitted to the lead
agency prior to the earlier of the
commencement of any ground-disturbing
activity, or the issuance of any permit
necessary to commence a grounddisturbing activity.

Submittal and review of
evidence that an
approved Native
American Monitor has
been retained and
provision of a copy of
the executed monitoring
agreement.

Prior to the earlier
of commencement of
any grounddisturbing activity or
issuance of any
permit necessary
to commence ground
-disturbing activity.

City of Aliso Viejo
Planning
Department

1. Construction coordination meeting shall be conducted prior to start of ground disturbing work (grading, trenching, or excavation) with Qualified Archaeologist, Construction Contractor, Tribal Representative(s).

Submittal and review of
construction
coordination meeting
agenda, attendance
Prior to the start of
ground-disturbing
work
City of Aliso Viejo
Planning
Department
2097

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 16
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
records, and meeting
notes

2. Tribal Cultural Resource Monitoring shall be conducted during all initial ground- disturbing activities until both the Archaeologist and Tribal Monitor determine monitoring is no longer needed. During construction, if cultural
materials or features are discovered. Construction
contractor, Archaeologist, Tribal Monitor(s) and Lead
Agency shall submit a discovery report documenting find, treatment measures, and confirmation that work did not
resume until treatment was completed. If human remains
are encountered during construction, the construction
contractor, County Coroner, NAHC, MLD and Tribal
Representative(s) shall follow the following: the coroner shall provide written documentation, the NAHC will be
notified, and there shall be confirmation of respectful treatment/reburial as directed by the MLD and Tribe.

Review of daily Tribal
monitoring logs; written
determination that
monitoring is no longer
required; and, if
resources or human
remains are
encountered, submittal
and review of discovery
reports, treatment
documentation,
required notifications,
and confirmation that
work resumed only after
treatment was
completed.

During all initial
ground-disturbing
activities; during
construction; upon
discovery of cultural
materials, features,
or human remains;
and prior to resuming
work in the discovery
area.

City of Aliso Viejo
Planning
Department

3. Qualified Archaeologist and/or Tribal Representative(s) shall submit documentation of recovered materials,
correspondence confirming tribal disposition decision
(e.g., reburial, return, or other treatment) during and following construction, if artifacts are recovered.

4. Qualified Archaeologist shall submit a Final Monitoring and Mitigation Summary Report and submit to project
applicant and appropriate CHRIS repository.

5. Lead Agency, Construction Contractor and or Tribal
Representative(s) shall submit records of coordination
and confirmation that tribal ceremonies or blessings were Submittal and review of
recovered-material
documentation and
Tribal disposition
correspondence, if
applicable; confirm
submittal of Final
Monitoring and
Mitigation Summary
Report; confirm
submittal of records of
During construction,
if artifacts are
recovered; following
completion of
monitoring and
mitigation; and prior
to and/or during
construction for
requested Tribal
ceremonies or
blessings
City of Aliso Viejo
Planning
Department
2098

PRESIDIO AT PACIFIC PARK RESIDENTIAL DEVELOPMENT

MITIGATION MONITORING AND REPORTING PROGRAM
FCS 17
Requirements Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
accommodated safely and respectfully prior to and/or
during construction, as requested by the Tribe.

6. Responsibility for conditions:
(a) Lead Agency shall ensure that all measures
are implemented, documented and verified
prior to and during construction activities;
and
(b) Tribal Participation be a consulting and
monitoring partner throughout all grounddisturbing activities; and (c) Compliance Verification shall include
documentation of implementation, including
monitoring logs, consultation records, and
correspondence. Records shall be
maintained in the project file by the Lead
Agency.
consultation and
coordination;
confirmation of
accommodated Tribal
ceremonies or
blessings, as
applicable; and
maintenance of
compliance records in
the project file. Review
Compliance Verification
documents.
2099
Presidio at Pacific Park Residential Development
FINAL
Initial Study/Mitigated Negative Declaration
State Clearinghouse Number 2026080753
PREPARED FOR:

City of Aliso Viejo
Community Development Department
12 Journey Suite 100
Aliso Viejo, CA 92656
949.425.2525
Contact: So Kim, Community Development Director
PREPARED BY:

FirstCarbon Solutions
250 Commerce, Suite 210
Irvine, CA 92602
714.508.4100
Contact: Cecilia So, Project Director
Tsui Li, Project Manager
September 28, 2026
2100
Presidio at Pacific Park Residential Development Final IS/MND City of Aliso Viejo
FCS 2-1
https://adecinnovations.sharepoint.com/sites/ESSite/Shared Documents/ES/Active Projects/6513 Brandywine Homes/0001 15 Argonaut/DOCUMENT/01 - ISMND/05 - RTC Draft/65130001 Sec01-00 Introduction and RTC intro.docx
1 - INTRODUCTION
Although a lead agency is not required to provide written responses to comments on proposed Negative Declarations (NDs) or Mitigated Negative Declarations (MNDs) under the California Environmental Quality Act (CEQA), the City of Aliso Viejo has evaluated the comments received on the Presidio at Pacific Park Residential Development (State Clearinghouse No. 2026080753) (proposed project) Draft Initial Study/Mitigated Negative Declaration (Draft IS/MND) and has elected to provide responses to the following environmental comments. None of the comments received results in the need to recirculate the Draft IS/MND or to prepare an Environmental Impact Report (EIR). Furthermore, no comments require revisions or clarifications to the Draft IS/MND.

The Final IS/MND includes the following contents:
• Draft IS/MND (provided under separate cover)
• Draft IS/MND appendices (provided under separate cover) • Responses to Written Comments
• Mitigation Monitoring and Reporting Program (provided under separate cover) 2 - RESPONSE TO WRITTEN COMMENTS
A list of public agencies, organizations, and individuals that provided comments on the Draft IS/MND is presented below. Each comment has been assigned a code. Individual comments within each communication have been numbered so comments can be crossed-referenced with responses.

Following this list, the text of the communication is reprinted and followed by the corresponding response.

Author Author Code
State Agencies
California Department of Transportation, District 12 ............................................................................A1 2101

CALIFORNIA STATE TRANSPORTATION AGENCY GAVIN NEWSOM, GOVERNOR California Department of Transportation
DISTRICT 12
1750 East 4+ Street, Suite 100 | SANTA ANA, CA 92705 (657) 328-6000 | FAX (657) 328-6522 TTY 711 https://dot.ca.gov/caltrans-near-me/district12
September 10, 2026
Ms. So Kim File: LDR/CEQA
Community Development Director SCH: 2026080753
City of Aliso Viejo 12-ORA-2026-03219
12 Journey Suite 100 SR 73, PM 15.028
Aliso Viejo, CA 92656 I-5, PM 18.329
Dear Ms. Kim,
Thank you for including the California Department of Transportation (Caltrans) in the review of the Mitigated Negative Declaration for the Presidio at Pacific Park Residential Development Project for the City of Aliso Viejo. The mission of Caltrans is improving lives and communities through transportation.

The proposed project involves the demolition of a 41,519 sq ft office building to construct a 58-unit, three-story, for-sale attached townhome community on approximately 4.4 acres. Regional access to the site is provided by State Route 73 (SR 73) and Interstate 5 (I-5). Caltrans is a commenting agency on this project and has the following comments:
]. Caltrans recognizes there is a strong link between transportation and land use.

Development can have a significant impact on traffic and congestion on State transportation facilities. In particular, the pattern of land use can affect both local vehicle miles traveled and the number of trips.

Caltrans supports collaboration with local agencies to work towards a safe, functional, interconnected, multi-modal transportation network integrated through applicable "smart growth" type land use planning and policies.

Additionally, Caltrans supports the City's progress in meeting its Regional Housing Needs Assessment (RHNA) allocation, and we encourage the City to promote the development of housing units for a variety of income levels.

2. The project is adjacent or close to several existing and planned bicycle facilities.

Therefore, Caltrans recommends the inclusion of secure and functional shortterm bike parking pursuant to CALGreen code. Short-term bike parking should be place on the ground floor in visible areas that are close to main entrances “Improving lives and communities through transportation” A1-1
A1-2
A1-3
2102
City of Aliso Viejo
September 10, 2026

Page 2 ends

and should be installed at least 24" away from walls and other objects (e.g. trash cans, plants, etc.}. With the increasing popularity of electric bikes and cargo/utility bikes, bike parking should also be designed to accommodate different styles, sizes, and weights of bikes (e.g. cargo bike, bike with trailer, adult tricycle, etc.).
o For additional guidance on providing functional bike parking, see the attached “Essentials of Bike Parking” guidance created by the Association of Pedestrian and Bicycle Professionals (link to online PDF:
hitps://www.apbp.org/Publications).

3. Caltrans encourages the design of Complete Streets that include high-quality pedestrian, bicycle, and transit facilities that are safe and comfortable for users of all ages and abilities. Improvements may include providing secure bicycle parking, pedestrian-oriented LED lighting, and comfortable connections to nearby active transportation and/or transit facilities. Complete Streets improvements also promote regional connectivity, improve air quality, reduce congestion, promote improved first-/last-mile connections, and increase safety for all modes of transportation.

4. Please consider the addition of high visibility crosswalks and ADA curb ramps on intersections in or adjacent to the project location that currently lack one or both.

5. Consider adding pedestrian scale lighting along sidewalks within or adjacent to project limits to improve pedestrian safety.

6. Consider installing or planning for zero- or near zero-emission infrastructure (e.g.

EV charging stations for delivery vehicles) to support California's transition to clean freight and reduce local air quality impacts.

7. Please ensure that all ingress/egress driveways and internal circulation routes are designed to accommodate the turning radii and maneuvering needs of large trucks and trailers, consistent with Caltrans and American Association of State Highway and Transportation Officials (AASHTO) standards.

8. Consider whether there is a need for short-term delivery parking or package drop-off areas to prevent double-parking or blocking of driveways and sidewalks. Encourage the use of shared package lockers to reduce the number of delivery stops and vehicle icling.
“Improving lives and communities through transportation” A1-3
cont.

A1-4
A1-5
A1-6
A1-7
A1-8
A1-9
2103
City of Aliso Viejo
September 10, 2026

Page 3 ends

9. Confirm that internal roads and parking areas are designed for safe truck circulation, including adequate width, turning radii, and clear signage.

Emergency access routes should be maintained and not obstructed by truck parking or event staging.

10. Assess potential conflict points between delivery vehicles and non-motorized

11. users at site entrances, internal walkways, and adjacent sidewalks. Incorporate design features such as clear signage, marked crosswalks, and sight distance improvements to enhance safety for all Users.

During construction phase, please ensure that appropriate detours, signage, and safety measures that prioritize the mobility, access and safety of all traffic modes, including bicyclists, pedestrians and transit users.

Please also evaluate how construction may alter wayfinding, transit signage and multimodal circulation in the immediate project area and surrounding vicinity.

Given the site's proximity to nearby rail and bus service, the project should consider both temporary construction-period access and long-term access for future users, including opportunities to support transit use.

12. All construction haul vehicles accessing the State Highway System must use routes approved by Caltrans. Any transportation of heavy construction equipment and/or materials which requires use of oversized-transport vehicles on State highways will require a Caltrans transportation permit. We recommend large size truck trips be limited to off-peak commute periods for the construction and operation phases. Construction truck loads should be covered with a tarpaulin cover.

13.The applicant shall ensure that construction-related traffic does not adversely impact operations on the State Highway System. All temporary traffic control within or affecting state highways state highways shall comply with the most current edition of the California Manual on Uniform Traffic Control Devices (CA MUTCD) and Caltrans standards. The applicant shall ensure that public safety and mobility are maintained during construction.
“Improving lives and communities through transportation” A1-10
A1-11
A1-12
A1-13
A1-14
A1-15
2104
City of Aliso Viejo
September 10, 2026

Page 4 ends

Please continue to coordinate with Caltrans for any future developments that could potentially impact State transportation facilities. If you have any questions, please do not hesitate to contact Joseph Jamoralin at [email protected], Sincerely,
Scott Shelley “eg 10, 2026 10:18:38 PDT)
Scott Shelley
Branch Chief, Local Development Review/Climate Resiliency Caltrans, District 12
“Improving lives and communities through transportation” A1-16
2105
15 ARGONAUT PROJECT ADMINISTRATIVE FINAL IS/MND RESPONSES TO

CITY OF ALISO VIEJO WRITTEN COMMENTS
FCS 7
Https://adecinnovations.sharepoint.com/sites/ESSite/Shared Documents/ES/Active Projects/6513 Brandywine Homes/0001 15 Argonaut/DOCUMENT/01 - ISMND/05 - RTC Draft/65130001 Sec02-00 Responses to Written Comments_tracks.docx
State Agencies
California Department of Transportation (A1)
Response to A1-1
The comment does not raise project-specific environmental concerns or comments related to the Draft IS/MND.

Response to A1-2
The City will continue coordinating with Caltrans and other stakeholders to evaluate transportation impacts and support a safe, functional, interconnected multimodal network.

Response to A1-3
The project site is located adjacent to existing Class II bicycle lanes along Glenwood Drive and Aliso Creek Road. In Section 2.17, Transportation of the Draft IS/MND, the analysis found that the project would not conflict with any bicycle facilities, and the proposed project would provide internal pedestrian walkways and sidewalks connecting to the existing pedestrian network. Each townhome would have a private garage which could be used for bicycle storage and parking. In addition, the project is required to comply with all applicable provisions of CALGreen and the California Building Standards Code during final design and building plan review. In response to this comment, the applicant has voluntarily agreed to install additional bike racks, which would be depicted in the final project plans. The City will review final project plans for compliance with applicable bicycle parking requirements.

Response to A1-4
The proposed project includes then “complete street” improvements that were described in the comment, Specifically, the proposed project provides internal pedestrian walkways, landscaped paseos, pedestrian-oriented lighting, sidewalks, and a network of common open space areas that connect residential units to project amenities and the existing public sidewalk system and bike lanes along Argonaut. Incorporation of site design features and public improvements will be reviewed by the City during project design and permitting, as applicable.

Response to A1-5
The project vicinity contains safe pedestrian crossings and ADA curb ramps. Existing pedestrian infrastructure already serves the project vicinity, including sidewalks on Glenwood Drive, Aliso Creek Road, and Argonaut, as well as signalized crosswalks at the Glenwood Drive/Aliso Creek Road intersection and nearby crossings connecting residents to Ridgecrest Park and surrounding destinations. The project would connect directly to this existing pedestrian network through internal sidewalks and walkways extending from the project entrance on Argonaut. As shown on the Project plans, the proposed sidewalks and crosswalks would be constructed of concrete, which provides visual contrast from the adjacent asphalt roadways and clearly delineates pedestrian and vehicular travel areas. ADA-compliant curb ramps would be provided as required by applicable accessibility standards and City development requirements. Any required frontage and accessibility improvements will be reviewed by the City during final site plan review. 2106
15 ARGONAUT PROJECT ADMINISTRATIVE FINAL IS/MND RESPONSES TO

CITY OF ALISO VIEJO WRITTEN COMMENTS
FCS 8
Https://adecinnovations.sharepoint.com/sites/ESSite/Shared Documents/ES/Active Projects/6513 Brandywine Homes/0001 15 Argonaut/DOCUMENT/01 - ISMND/05 - RTC Draft/65130001 Sec02-00 Responses to Written Comments_tracks.docx
Response to A1-6
Section 2.1 of the Draft IS/MND specifically states that the project would incorporate shielded wallmounted fixtures, pedestrian-scale lighting, and limited pole-mounted lighting designed to illuminate entries, walkways, private streets, parking areas, and common-use spaces while minimizing off-site light spill. Therefore, pedestrian safety considerations associated with lighting are incorporated into the project design and applicable City standards.

Response to A1-7
The project will comply with all applicable State and local building code requirements, including applicable electric vehicle infrastructure requirements in effect at the time of building permit issuance.

The City notes that sustainable design features have been incorporated into the proposed project.

Specifically, as described in Section 2.6, Energy of the Draft IS/MND, all 58 residential units would be constructed as solar-powered, all-electric townhomes, eliminating the need for on-site natural gas infrastructure and supporting California's building decarbonization objectives. The proposed project also includes electric vehicle charging infrastructure consistent with applicable CALGreen requirements and EV-capable garage infrastructure to support future electric vehicle ownership by residents.

Response to A1-8
The proposed project has been designed to comply with applicable emergency access and circulation requirements. The proposed development would utilize the existing driveway on Argonaut and includes an internal private roadway system that provides access to all residential units, guest parking spaces, and emergency service vehicles. The site plan includes an Orange County Fire Authority (OCFA) hammerhead turnaround and internal circulation network specifically designed to facilitate emergency response vehicle access throughout the community. Further, as described in the Project Description of the Draft IS/MND, the project has been designed to comply with applicable emergency service provider standards, including a minimum inside turning radius of 20 feet and outside turning radius of 49 feet.

In addition, final engineering plans will be reviewed by the City and OCFA during the Site Development Permit and building permit processes to ensure continued compliance with all applicable circulation, access, and emergency response standards. Therefore, adequate internal circulation and vehicle maneuverability have already been incorporated into the project design.

Response to A1-9
Given the residential nature and relatively small scale of the proposed 58-unit townhome development, delivery activity is expected to be similar to that associated with typical residential neighborhoods and can be accommodated within the project's internal circulation and parking facilities.

Response to A1-10
2107
15 ARGONAUT PROJECT ADMINISTRATIVE FINAL IS/MND RESPONSES TO

CITY OF ALISO VIEJO WRITTEN COMMENTS
FCS 9
Https://adecinnovations.sharepoint.com/sites/ESSite/Shared Documents/ES/Active Projects/6513 Brandywine Homes/0001 15 Argonaut/DOCUMENT/01 - ISMND/05 - RTC Draft/65130001 Sec02-00 Responses to Written Comments_tracks.docx
The proposed project has been designed to comply with applicable City and OFCA access requirements. The project includes an internal private roadway network, emergency access routes, and an OCFA-compliant hammerhead turnaround to facilitate emergency vehicle maneuvering throughout the site. As described in the Project Description of the Draft IS/MND, the internal circulation system has been designed with a minimum inside turning radius of 20 feet and outside turning radius of 49 feet to accommodate emergency and service vehicles. Additionally, final engineering plans will be reviewed by the City and OCFA to ensure continued compliance with applicable circulation and emergency access standards.

Response to A1-11
As described in Section 2.17, Transportation of the Draft IS/MND, the project would not create transportation hazards and would comply with applicable City circulation and design standards.

Project access points and internal circulation routes will be subject to final engineering review to ensure adequate sight distance and safe interaction between vehicles and pedestrians. Additionally, ingress and egress areas will be designed to maintain visibility and remain unobstructed by landscaping, signage, or other site features. Accordingly, pedestrian and vehicle interactions have been considered through project design and City review requirements.

Response to A1-12
Construction activities would occur within the project site and would be required to comply with applicable City requirements and permit conditions related to public safety, temporary traffic control, and construction management. The proposed project would maintain access to surrounding roadways and would not require permanent modifications to the existing transportation network. Any temporary traffic control measures required during construction would be implemented in accordance with applicable City standards and permit requirements. Compliance with these requirements would ensure that commenter’s recommendation is incorporated into the project and public safety and mobility are maintained during project construction.

Response to A1-13
Section 2.17 of the Draft IS/MND identifies existing transit service in the project vicinity and concludes that the project would not conflict with applicable transportation plans, policies, or programs supporting transit, bicycle, or pedestrian facilities. During construction, the project would comply with applicable City requirements for temporary traffic control, signage, wayfinding, and maintenance of safe pedestrian, bicycle, transit, and vehicular access.

At operation, the proposed project includes pedestrian walkways and sidewalk connections that provide residents with access to the existing transportation network serving the surrounding community.

Response to A1-14
The project applicant and its contractors will be responsible for obtaining any required permits and complying with all applicable federal, State, and local regulations governing construction traffic and transport of oversized equipment.
2108
15 ARGONAUT PROJECT ADMINISTRATIVE FINAL IS/MND RESPONSES TO

CITY OF ALISO VIEJO WRITTEN COMMENTS
FCS 10
Https://adecinnovations.sharepoint.com/sites/ESSite/Shared Documents/ES/Active Projects/6513 Brandywine Homes/0001 15 Argonaut/DOCUMENT/01 - ISMND/05 - RTC Draft/65130001 Sec02-00 Responses to Written Comments_tracks.docx
Response to A1-15
Construction activities associated with the proposed project would occur within the project site and would be subject to all applicable City, State, and agency requirements related to traffic control, public safety, and construction management. Any temporary traffic control measures required during construction would be implemented through applicable permit requirements and would be required to comply with relevant regulatory standards. As discussed in Section 2.17, Transportation of the Draft IS/MND, the proposed project would maintain emergency access and would not result in significant transportation impacts.

Response to A1-16
The comment does not raise project-specific environmental concern or comments related to the Draft IS/MND. The City is committed to ongoing coordination with Caltrans and other stakeholders to ensure that land use decisions are made with a comprehensive understanding of their transportation impacts.
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60367.01460\45470645.1
RESOLUTION NO. 2026-___

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF ALISO

VIEJO, CALIFORNIA, APPROVING AN AMENDMENT TO THE

GENERAL PLAN LAND USE DESIGNATION AND ASSOCIATED LAND

USE MAP FROM BUSINESS PARK TO MEDIUM DENSITY
RESIDENTIAL FOR THE DEVELOPMENT OF A 58-UNIT RESIDENTIAL TOWNHOME COMMUNITY LOCATED AT 15 ARGONAUT (APN: 623-
093-10 & 623-093-11).

WHEREAS, on April 15, 2026, Brandywine Acquisition Group, LLC. (“Applicant”) submitted a general plan amendment, zone change, vesting tentative tract map, site development permit, and a development agreement application to demolish an existing office building and accommodate the construction of a multi-family residential community at 15 Argonaut (“Project”);
WHEREAS, pursuant to section 21067 of the Public Resources Code, and section 15367 of the State CEQA Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.), the City is the lead agency for the proposed Project and has prepared an Initial Study/Mitigated Negative Declaration (SCH#2026080753) (“IS/MND”) and a Mitigation Monitoring and Reporting Program (“MMRP”) for the Project;
WHEREAS, on March 4, 2026, the City Council held a duly noticed public review to receive and provide initial feedback on concept plans for the Project; WHEREAS, on September 15, 2026, the City gave public notice of the City Council public hearing for consideration of Mitigated Negative Declaration CEQA-2026-01004, General Plan Amendment GPA-2026-01002, Zone Change ZC-2026-00001, Vesting Tentative Tract Map 19489, Site Development Permit SDP-2026-01001 and Development Agreement DA-2026-01002 for the Project by publishing in a newspaper of general circulation; by posting notices at City Hall and the Project site; and by mailing notices to owners of property within 300 feet, to the project applicant, and to local agencies that provide water, sewage, electricity and schools;
WHEREAS, on October 7, 2026, the City Council held a public hearing as prescribed by law and considered written and verbal public testimony that was submitted prior to the hearing and during the hearing, and evidence and recommendations presented by staff in the agenda report and oral presentation; and
WHEREAS, all other legal prerequisites to the adoption of this Resolution have occurred.

NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF ALISO VIEJO AS FOLLOWS:
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Section 1. Incorporation of Recitals. The City Council hereby finds and determines that all of the recitals set forth above are true and correct. The above recitals are hereby incorporated as substantive findings of this Resolution.

Section 3. Findings for General Plan Amendment GPA-2026-01002. Pursuant to AVMC 15.78.020 (General Plan Amendments), the City Council hereby makes the following findings of fact and approves an amendment to the General Plan land use designation and associated land use map from Business Park to Medium Density Residential, as set forth in Exhibit “A”, which is attached hereto and incorporated herein by reference.

1. Public Welfare. Approval of the amendment will not create conditions materially detrimental to the public health, safety and general welfare. While the Site is located within a larger business park area, it is situated in proximity to the recently approved 95 Argonaut residential development, which also involved the redevelopment of a business park use for residential use. Similar to 95 Argonaut, the proposed Project would introduce a three-story attached townhome development at a scale compatible with existing residential neighborhoods that are located directly north of the Site across Glenwood Drive, including both multi-family and single-family residential development. The proposed Project incorporates similar architectural features as 95 Argonaut and adjacent residential communities such as stucco exteriors, tile roofs, wrought-iron balconies, recessed entries, and shared openspace areas. As proposed, the Project incorporates architectural and site design elements that are generally consistent with the character of nearby residential development and would provide a transition between the surrounding residential neighborhoods and the remaining business park uses in the area. Both projects feature multi-story attached residential units with comparable architectural character, private garages, guest parking, landscaped common open space, and enhanced site entries. Additionally, the Site is situated in an area with established infrastructure, including roads, utilities, and public services, that can adequately support residential development. As part of the environmental assessment, the Project required comprehensive studies addressing air quality, energy, greenhouse gas emissions, biological resources, cultural resources, geotechnical conditions, hydrology and water quality, noise, and transportation impacts. As discussed further in the Environmental Assessment section, below, these studies concluded that the Project would result in less-than-significant impacts with the implementation of proposed mitigation measures. The Project plans also cleared preliminary review by the Orange County Fire Authority (OCFA). Furthermore, the Project aligns with 2111

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60367.01460\45470645.1
the City’s housing goals by facilitating the development of new housing opportunities. Future construction on the Site will be subject to plan check review and inspection process to ensure full compliance with applicable building and safety standards.

2. Internal General Plan Consistency. The amendment is internally consistent with those goals, objectives, and policies of the general plan that are not being amended. The proposed amendment is consistent with the goals and policies of the General Plan listed below in that it incorporates landscaping aligned with the City Council-approved plant palette, emphasizing low-water, drought-tolerant species; features building materials, colors, and architectural design that are compatible with the surrounding residential communitiespublic benefit fees ; proposes three affordable housing units restricted to very low-income households, thereby enhancing housing diversity and affordability; and introduces rezoning to facilitate residential development that includes affordable units in support of the City’s housing objectives. In the General Plan, 'COS' refers to Conservation and Open Space policies, 'H' for Housing policies and goals, and 'LU' for Land Use policies.
 Policy COS-1.2 Reduce the amount of water used for landscaping and increase use of native and low water plants. Maximize use of native, lowwater plants for landscaping of areas adjacent to sidewalks or other impermeable surfaces.
 Policy COS-4.2 Encourage and maintain high-quality architectural and landscaping designs that enhance or complement the community’s visual character.
 Policy COS-7.5 Ensure that new development provides park land and/or improvements at a fair share ratio, pursuant to the City’s Parkland Ordinance.
 Goal H-1: Encourage a diversity of housing types and provide affordability levels within Aliso Viejo to meet the needs of community residents.  Policy H-1.1 Identify sites appropriate for the development of a variety of housing types and price ranges to meet the needs of all socioeconomic segments of the community through the disbursement of affordable units in projects.
 Policy H-1.2 Encourage through the use of density bonuses and rezoning to allow for residential development, development of affordable housing opportunities throughout the community, as well as development of housing for elderly and low- and moderate-income households near public transportation services.
 Policy H-1.4 Ensure that a portion of future residential development is affordable to low- and very-low-income households by designating certain sites as having the potential to be used for residential uses.  Policy H-3.8 Review existing zoning policies and explore zoning changes to facilitate the development of affordable housing.
2112

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60367.01460\45470645.1
 Policy LU-12.2 As a condition upon new development, require payment of park fees and/or dedication and provision of parkland, recreation facilities and/or multi-use trails that improve the public and private recreation system.

3. Land Use Compatibility. In the case of amendments to the General Plan land use policy map, the new designation is compatible with the designations on nearby properties. The Site is located at the edge of a larger business park and directly across from established multi-family and single-family residential neighborhoods.

The proposed project is similar to a recently approved development at 95 Argonaut project, which is located on the same street within the same business park area.

Both projects involve the conversion of an office property to a residential townhome community and introduce a land use that is compatible with nearby residential neighborhoods. The adjacent multi-family development shares several characteristics with the Project, including large attached-unit buildings, stucco exteriors, tile roofing, wrought iron balconies, recessed entryways, and shared open space without private driveways. These similarities ensure architectural and functional continuity between the Project and existing residential uses. The proposed land use designation therefore complements the surrounding residential character.

4. Property Suitability. In the case of amendments to the general plan land use policy map, the new designation is suitable for the location, access, visual character and topography of the subject property. The property is located along established roadways with adequate vehicular and pedestrian access and is supported by existing infrastructure, including utilities and public services, sufficient to accommodate residential development. The Site is generally flat within the developed portion, with sloped areas adjacent to Glenwood Drive and Aliso Creek Road. The proposed Project would retain the existing slope, utilize existing access from Argonaut, and incorporate site improvements consistent with applicable engineering and design standards. The proposed residential development includes architectural, landscaping, and site design elements that are similar to those found in nearby residential communities north of the Site, including attached residential development across Glenwood Drive and also the recently approved residential townhomes at 95 Argonaut. In addition, the Site is located between existing residential neighborhoods and surrounding business park uses, making it suitable for the proposed Medium Density Residential land use designation.

Section 4. Severability. If any provision of this Resolution or the application thereof to any person or circumstance is held invalid, such invalidity shall not affect other provisions or applications of this Resolution that can be given effect without the invalid provision or application, and to this end the provisions of this Resolution are severable.

The City Council hereby declares that it would have adopted this Resolution irrespective of the invalidity of any particular portion thereof.
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Section 5: Location of Documents. The administrative record for the Project is maintained at City Hall located at 12 Journey, Suite 100, Aliso Viejo, CA 92656. The custodian of records is the City Clerk.

Section 6: Effective Date. This General Plan Amendment shall not take effect unless and until Zone Change ZC-2026-01001, Vesting Tentative Tract Map 19489, Site Development Permit SDP-2026-01001, and Development Agreement DA-2026-01002 are each approved by the City Council and have become effective, and the associated Development Agreement is approved by the City Council and executed by both parties thereto.

Section 7. Execution of Resolution. The Mayor shall sign this Resolution and the City Clerk shall attest and certify to the passage and adoption thereof.

PASSED, APPROVED AND ADOPTED this 7th day of October 2026. __________________________
Max Duncan, Mayor
APPROVED AS TO FORM: ATTEST:

__________________________ __________________________
Scott C. Smith, City Attorney Maria Kendig, City Clerk
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60367.01460\45470645.1

STATE OF CALIFORNIA )
COUNTY OF ORANGE ) ss.

CITY OF ALISO VIEJO )
I,Maria Kendig, City Clerk of the City of Aliso Viejo, California, DO HEREBY CERTIFY that the foregoing is the original of Resolution No. 2026-__ duly passed and adopted by the City Council of the City of Aliso Viejo at their regular meeting held on the 7th day of October 2026, by the following roll call vote, to wit:

AYES:

NOES:

ABSENT:
___________________________

MARIA KENDIG, CITY CLERK

(SEAL)
2115

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60367.01460\45470645.1
Exhibit “A”
Amendment to the General Plan Land Use Map
Case No. GPA-2026-01002
Property Location – 15 Argonaut (see red-circled area below) Existing Land Use Designation – Business Park (“BP”)
Proposed Land Use Designation – Medium Density Residential (Max. 18 units/acre) (“MDR”)
2116

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ORDINANCE NO. 2026-___

AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF ALISO

VIEJO, CALIFORNIA, APPROVING A ZONE CHANGE FROM
BUSINESS PARK 2 TO MEDIUM DENSITY RESIDENTIAL DISTRICT
FOR THE DEVELOPMENT OF A 58-UNIT RESIDENTIAL TOWNHOME
COMMUNITY LOCATED AT 15 ARGONAUT (623-093-10 AND 623-093- 11).

WHEREAS, on April 15, 2026, Brandywine Acquisition Group, LLC. (“Applicant”) submitted a general plan amendment, zone change, vesting tentative tract map, site development permit, and a development agreement application to demolish an existing office building and accommodate the construction of a multi-family residential community at 15 Argonaut (“Project”);
WHEREAS, pursuant to section 21067 of the Public Resources Code, and section 15367 of the State CEQA Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.), the City is the lead agency for the proposed Project and has prepared an Initial Study/Mitigated Negative Declaration (SCH #2026080753) (“IS/MND”) and a Mitigation Monitoring and Reporting Program (“MMRP”) for the Project;
WHEREAS, on October 7, 2026, the City Council held a duly noticed public hearing to receive and consider public testimony and evidence regarding the Project; WHEREAS, on September 15, 2026, the City gave public notice of the City Council public hearing for consideration of Mitigated Negative Declaration CEQA-2026-01004, General Plan Amendment GPA-2026-01002, Zone Change ZC-2026-00001, Vesting Tentative Tract Map 19489, Site Development Permit SDP-2026-01001 and Development Agreement DA-2026-01002 for the Project by publishing in a newspaper of general circulation; by posting notices at City Hall and the Project site; and by mailing notices to owners of property within 300 feet, to the project applicant, and to local agencies that provide water, sewage, electricity and schools;
WHEREAS, on October 7, 2026, the City Council held a duly noticed public hearing as prescribed by law and considered written and verbal public testimony that was submitted prior to the hearing and during the hearing, and evidence and recommendations presented by staff in the agenda report and oral presentation and introduced the Ordinance; and
WHEREAS, all legal prerequisites to the adoption of this Ordinance have occurred.

NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF ALISO VIEJO DOES ORDAIN AS FOLLOWS:
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Section 1. Incorporation of Recitals. The City Council hereby finds and determines that all of the recitals set forth above are true and correct. The above recitals are hereby incorporated as substantive findings of this Ordinance.

Section 2. CEQA. Pursuant to the California Environmental Quality Act (Public Resources Code, § 21000 et seq.) and the State CEQA Guidelines (California Code of Regulations, title 14, § 15000 et seq.) (Collectively, “CEQA”), the City Council adopted Resolution No.___________, determining that there is no substantial evidence that the approval of the Project would result in a significant adverse effect on the environment, provided appropriate mitigation measures, as identified in the MMRP, are imposed on the Project;
Section 3. Findings for Zone Change ZC-2026-00001. Pursuant to AVMC 15.78.040 (Zone Change and Prezoning), the City Council hereby makes the following findings of fact and approves the Zone Change ZC-2026-00001 from Business Park 2 to Medium Density Residential, as set forth in Exhibit “A”, which is attached hereto and incorporated herein by reference.

1. Public Welfare. Approval of the zone change will not create conditions materially detrimental to the public health, safety and general welfare. While the Site is located within a larger business park area, it is situated in proximity to the recently approved 95 Argonaut residential development, which also involved the redevelopment of a business park use for residential use. Similar to 95 Argonaut, the proposed Project would introduce a three-story attached townhome development at a scale compatible with existing residential neighborhoods that are located directly north of the Site across Glenwood Drive, including both multi-family and single-family residential development. The proposed Project incorporates similar architectural features as 95 Argonaut and adjacent residential communities such as stucco exteriors, tile roofs, wrought-iron balconies, recessed entries, and shared open-space areas. As proposed, the Project incorporates architectural and site design elements that are generally consistent with the character of nearby residential development and would provide a transition between the surrounding residential neighborhoods and the remaining business park uses in the area. Both projects feature multi-story attached residential units with comparable architectural character, private garages, guest parking, landscaped common open space, and enhanced site entries. Additionally, the Site is situated in an area with established infrastructure, including roads, utilities, and public services, that can adequately support residential development. As part of the environmental assessment, the Project required comprehensive studies addressing air quality, energy, greenhouse gas emissions, biological resources, cultural resources, geotechnical conditions, hydrology and water quality, noise, and transportation impacts. As discussed further in the Environmental Assessment section below, these studies concluded that the Project would result in less-than-significant impacts with the implementation of proposed mitigation measures. The Project plans also cleared preliminary review by the Orange County Fire Authority (OCFA). Furthermore, the Project aligns with the City’s housing goals by facilitating the development of new 2118

Page 3 of 7 ends

housing opportunities. Future construction on the Site will be subject to plan check review and inspection process to ensure full compliance with applicable building and safety standards.

2. General Plan Consistency. The amendment is internally consistent with those goals, objectives, and policies of the general plan that are not being amended. The proposed amendment is consistent with the goals and policies of the General Plan listed below in that it incorporates landscaping aligned with the City Councilapproved plant palette, emphasizing low-water, drought-tolerant species; features building materials, colors, and architectural design that are compatible with the surrounding residential communities;public benefit fees ; proposes three affordable housing units restricted to very low-income households, thereby enhancing housing diversity and affordability; and introduces rezoning to facilitate residential development that includes affordable units in support of the City’s housing objectives. In the General Plan, 'COS' refers to Conservation and Open Space policies, 'H' for Housing policies and goals, and 'LU' for Land Use policies.  Policy COS-1.2 Reduce the amount of water used for landscaping and increase use of native and low water plants. Maximize use of native, low-water plants for landscaping of areas adjacent to sidewalks or other impermeable surfaces.  Policy COS-4.2 Encourage and maintain high-quality architectural and landscaping designs that enhance or complement the community’s visual character.
 Policy COS-7.5 Ensure that new development provides park land and/or improvements at a fair share ratio, pursuant to the City’s Parkland Ordinance.  Goal H-1: Encourage a diversity of housing types and provide affordability levels within Aliso Viejo to meet the needs of community residents.  Policy H-1.1 Identify sites appropriate for the development of a variety of housing types and price ranges to meet the needs of all socioeconomic segments of the community through the disbursement of affordable units in projects.
 Policy H-1.2 Encourage through the use of density bonuses and rezoning to allow for residential development, development of affordable housing opportunities throughout the community, as well as development of housing for elderly and low- and moderate-income households near public transportation services.
 Policy H-1.4 Ensure that a portion of future residential development is affordable to low- and very-low-income households by designating certain sites as having the potential to be used for residential uses.  Policy H-3.8 Review existing zoning policies and explore zoning changes to facilitate the development of affordable housing.
 Policy LU-12.2 As a condition upon new development, require payment of park fees and/or dedication and provision of parkland, recreation facilities and/or multi-use trails that improve the public and private recreation system. 2119

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3. Land Use Compatibility. The zone change is compatible with the zoning and land use on nearby properties. The Site is located at the edge of a larger business park and directly across from established multi-family and single-family residential neighborhoods. The proposed project is similar to a recently approved development at 95 Argonaut project, which is located on the same street within the same business park area. Both projects involve the conversion of an office property to a residential townhome community and introduce a land use that is compatible with nearby residential neighborhoods. The adjacent multi-family development shares several characteristics with the Project, including large attached-unit buildings, stucco exteriors, tile roofing, wrought iron balconies, recessed entryways, and shared open space without private driveways. These similarities ensure architectural and functional continuity between the Project and existing residential uses. The proposed land use designation therefore complements the surrounding residential character.

4. Property Suitability. The zone change is suitable for the location, access, visual character and topography of the subject property. The property is located along established roadways with adequate vehicular and pedestrian access and is supported by existing infrastructure, including utilities and public services, sufficient to accommodate residential development. The Site is generally flat within the developed portion, with sloped areas adjacent to Glenwood Drive and Aliso Creek Road. The proposed Project would retain the existing slope, utilize existing access from Argonaut, and incorporate site improvements consistent with applicable engineering and design standards. The proposed residential development includes architectural, landscaping, and site design elements that are similar to those found in nearby residential communities north of the Site, including attached residential development across Glenwood Drive and also the recently approved residential townhomes at 95 Argonaut. In addition, the Site is located between existing residential neighborhoods and surrounding business park uses, making it suitable for the proposed Medium Density Residential land use designation.

Section 4. Severability. If any provision of this Ordinance or its application to any person or circumstance is held to be invalid by a court of competent jurisdiction, such invalidity has no effect on the other provisions or applications of the Ordinance that can be given effect without the invalid provision or application, and to this extent, the provisions of this Ordinance are severable. The City Council declares that it would have adopted this Ordinance irrespective of the invalidity of any portion thereof.

Section 5. Location of Documents. The administrative record for the Project is maintained at City Hall located at 12 Journey, Suite 100, Aliso Viejo, CA 92656. The custodian of records is the City Clerk.

Section 6. Effective Date. This Zone Change Ordinance shall not take effect unless and until General Plan Amendment 2026-01002, Vesting Tentative Tract Map 19489, Site Development Permit SDP-2026-01001 and Development Agreement 2026- 2120

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01002 are each approved by the City Council and have become effective, and the associated Development Agreement is approved by the City Council and executed by both parties thereto.

Section 7. City Clerk’s Certification. The City Clerk shall certify to the adoption of this Ordinance and cause a summary thereof to be published five days prior to the date of adoption of this Ordinance, and, within 15 days after adoption, the City Clerk shall cause to be published the aforementioned summary and shall post a certified copy of this Ordinance, together with the vote for and against the same, in the Office of the City Clerk.

PASSED, APPROVED AND ADOPTED this 21st day of October, 2026. __________________________
Max Duncan
Mayor
APPROVED AS TO FORM: ATTEST:

___________________________ ___________________________ Scott C. Smith, City Attorney Maria Kendig, City Clerk
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STATE OF CALIFORNIA )
COUNTY OF ORANGE ) ss.

CITY OF ALISO VIEJO )
I, Maria Kendig, City Clerk of the City of Aliso Viejo, California, DO HEREBY CERTIFY that the foregoing is the original of Ordinance No. 2026-__ duly passed and adopted by the City Council of the City of Aliso Viejo at their regular meeting held on the 21st day of October 2026, by the following roll call vote, to wit:

AYES:

NOES:

ABSENT:
___________________________

MARIA KENDIG, CITY CLERK

(SEAL)
I hereby certify that the foregoing is the original of Ordinance No. 2026-__ duly passed and adopted by the Aliso Viejo City Council at its regular meeting held October 21, 2026, and that the Summary of the Ordinance was published on ______ and ______ in the Laguna Niguel News.
___________________________

MARIA KENDIG, CITY CLERK
(SEAL)
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Exhibit “A”
Zone Change Map
Case No. ZC-2026-01001
Property Location – 15 Argonaut (see red-circled area below) Existing Zoning District Designation – Business Park 2 (“BP-2”) Proposed Zoning District Designation – Medium Density Residential (Max. 18 units/acre) (“MDR”)
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RESOLUTION NO. 2026-___

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF ALISO VIEJO, CALIFORNIA, APPROVING VESTING TENTATIVE TRACT MAP 19489

FOR SUBDIVISION INTO CONDOMINIUM PURPOSES AND SITE
DEVELOPMENT PERMIT (SDP-2026-01001) TO ALLOW THE
DEVELOPMENT OF A 58-UNIT RESIDENTIAL TOWNHOME COMMUNITY LOCATED AT 15 ARGONAUT (APN: 623-093-10 & 623-093-11).

WHEREAS, on April 15, 2026, Brandywine Acquisition Group, LLC. (“Applicant”) submitted a general plan amendment, zone change, vesting tentative tract map, site development permit, and a development agreement application to demolish an existing office building and accommodate the construction of a multi-family residential community at 15 Argonaut (“Project”);
WHEREAS, pursuant to section 21067 of the Public Resources Code, and section 15367 of the State CEQA Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.), the City is the lead agency for the proposed Project and has prepared an Initial Study/Mitigated Negative Declaration (SCH#2026080753) (“IS/MND”) and a Mitigation Monitoring and Reporting Program (“MMRP”) for the Project;
WHEREAS, the public benefits include, among other things, park in-lieu fees, as authorized by law and the City’s ordinances, to rehabilitate and improve existing open space and recreational facilities in the City, including but not limited to, the Aquatic Center, Iglesia Community Center and Park, and the Ranch (“Facilities”) in order to maintain the City’s high standard of recreation and community services while accommodating a growing population, including future residents of the proposed subdivision; WHEREAS, residents throughout the City regularly use the Facilities due to the variety of programs and services offered. Although the Facilities are located outside of the subdivision, future residents of the subdivision will undoubtedly use and benefit from use of the Facilities as well;
WHEREAS, on March 4, 2026, the City Council held a duly noticed public review to receive and provide initial feedback on concept plans for the Project; WHEREAS, on September 15, 2026, the City gave public notice of the City Council public hearing for consideration of Mitigated Negative Declaration CEQA-2026-01004, General Plan Amendment GPA-2026-01002, Zone Change ZC-2026-00001, Vesting Tentative Tract Map 19489, Site Development Permit SDP-2026-01001 and Development Agreement DA-2026-01002 for the Project by publishing in a newspaper of general circulation; by posting notices at City Hall and the Project site; and by mailing notices to owners of property within 300 feet, to the project applicant, and to local agencies that provide water, sewage, electricity and schools;
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WHEREAS, on October 7, 2026, the City Council held a public hearing as prescribed by law and considered written and verbal public testimony that was submitted prior to the hearing and during the hearing, and evidence and recommendations presented by staff in the agenda report and oral presentation; and
WHEREAS, all legal prerequisites to the adoption of this Resolution have occurred.

NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF ALISO VIEJO AS FOLLOWS:

Section 3. Findings for Vesting Tentative Tract Map 19489. Pursuant to the requirements of the California Subdivision Map Act (Government Code Section 66410 et. seq.) and AVMC Title 14 (Subdivisions), the City Council hereby makes the following findings of fact and approves the Vesting Tentative Tract Map (“VTTM”) 19489 as set forth in the Project plans as set forth in Exhibit “B”, Sheets 1 and 2 and subject to the conditions of approval as set forth in Exhibit “A”, which are attached hereto and incorporated herein by reference.

A. The proposed map is consistent with the applicable General and Specific Plans. The Site has a General Plan land use designation of Business Park. The Applicant proposes a General Plan Amendment to re-designate the property for Medium Density Residential, which allows for residential development of eight to 18 dwelling units per acre. The Vesting Tentative Tract Map proposes 58 multi-family homes on 4.4 acres, resulting in a density of 13.2 dwelling units per acre. As conditioned, the Vesting Tentative Tract Map will not take effect unless the General Plan Amendment, Zone Change, Site Development Permit, and Development Agreement take effect. Accordingly, the proposed map would be consistent with the applicable General Plan Land Use designation.

There is no applicable Specific Plan for the Site.

B. The design or improvement of the proposed subdivision is consistent with the General and Specific Plans. The Project is consistent with the goals and policies of the Conservation and Open Space (COS), Housing (H), and Land Use element (LU) listed below in that the Project promotes orderly growth, 2125

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provides a compatible transition between non-residential and residential uses, supports housing objectives by creating new residential opportunities, and utilizes existing infrastructure in a manner consistent with the community’s long-term vision and planning framework. The Project is also subject to mitigation measures and conditions of approval that address potential impacts related to traffic, noise, air quality, and emergency access. There is no applicable Specific Plan for the Project site.
 Policy COS-1.2 Reduce the amount of water used for landscaping and increase use of native and low water plants. Maximize use of native, lowwater plants for landscaping of areas adjacent to sidewalks or other impermeable surfaces.
 Policy COS-4.2 Encourage and maintain high-quality architectural and landscaping designs that enhance or complement the community’s visual character.
 Policy COS-7.5 Ensure that new development provides park land and/or improvements at a fair share ratio, pursuant to the City’s Parkland Ordinance.
 Goal H-1: Encourage a diversity of housing types and provide affordability levels within Aliso Viejo to meet the needs of community residents.  Policy H-1.1 Identify sites appropriate for the development of a variety of housing types and price ranges to meet the needs of all socioeconomic segments of the community through the disbursement of affordable units in projects.
 Policy H-1.2 Encourage through the use of density bonuses and rezoning to allow for residential development, development of affordable housing opportunities throughout the community, as well as development of housing for elderly and low- and moderate-income households near public transportation services.
 Policy H-1.4 Ensure that a portion of future residential development is affordable to low- and very-low-income households by designating certain sites as having the potential to be used for residential uses.  Policy H-3.8 Review existing zoning policies and explore zoning changes to facilitate the development of affordable housing.
 Policy LU-12.2 As a condition upon new development, require payment of park fees and/or dedication and provision of parkland, recreation facilities and/or multi-use trails that improve the public and private recreation system.

C. The proposed subdivision conforms to all applicable zoning standards set forth in AVMC Title, as required by AVMC Section 14.08.050. With the proposed zone change to Medium Density Residential, together with the associated development, the Project conforms with all applicable zoning standards set forth in the AVMC. The Project includes requests for incentives, concessions, and waivers pursuant to California State Density Bonus Law (Government Code Section 65915). The Project provides three deed-restricted very lowincome units, representing at least five percent of the total units, and therefore 2126

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qualifies for consideration of the requested density bonus incentives and waivers. The requested modifications include a one-foot increase in building height, a reduction in common open space, reduced perimeter setbacks, and reduced minimum boundary landscaping standards.

In addition, the Project qualifies for a reduced parking requirement under State Density Bonus Law. Based on the applicable density bonus parking ratio, the Project is required to provide a minimum of 130 parking spaces. The Project proposes 140 parking spaces, consisting of 116 private residential parking spaces within garages and 24 unenclosed guest parking spaces, including one ADA-accessible space. Accordingly, the Project exceeds the minimum parking requirement established under State Density Bonus Law.

With these provisions, the Project conforms to the permitted use requirements and development standards of the zoning code and remains consistent with all applicable Specific Plan regulations.

D. The site is physically suitable for the type of development. The Site is generally level, has adequate access from existing public streets, and is served by established infrastructure systems including water, sewer, storm drainage, and utilities. The Site’s size, configuration, and surrounding land use context are appropriate to accommodate the Project consistent with applicable zoning and General Plan designations. No unusual topographic, geologic, or environmental conditions have been identified that would render the site unsuitable for residential use.

E. The site is physically suitable for the proposed density of development. The Project includes a General Plan Amendment to re-designate the property to Medium Density Residential, which permits residential development at a range of eight to 18 dwelling units per acre. The Vesting Tentative Tract Map proposes 58 multi-family homes on 4.4 acres, resulting in a density of approximately 13.2 dwelling units per acre. This proposed density falls within the allowable range for the Medium-Density Residential designation.

F. The design of the subdivision and the proposed improvements are not likely to cause substantial environmental damage or substantial and avoidable injury to fish or wildlife or their habitat. The Project site is currently developed with an office building, surface parking lot, and landscaping. There is no fish, wildlife, or any habitat that would be affected by the Project.

G. The design of the subdivision or type of improvements is not likely to cause serious public health problems. The Project will be served by existing off-site infrastructure, with new on-site water, sewer, and storm drain facilities designed to connect to and extend those systems. All facilities have adequate capacity to accommodate the proposed residential use. The subdivision design incorporates standard improvements, including paved streets, sidewalks, street lighting, and utility connections that will be constructed in compliance with 2127

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applicable building codes and City engineering standards. The Initial Study prepared for the Project did not identify any conditions that would result in significant public health impacts, and all potentially significant effects have been mitigated to less-than-significant levels.

H. The design of the subdivision or the type of improvements will not conflict with existing easements, acquired by the public at large, for access through or use of property within the subdivision. The Project as conditioned requires the Applicant to obtain easement holders’ authorization for any improvements or encroachments prior to building permit issuance.

I. The advisory agency shall determine whether the discharge of waste from the proposed subdivision into an existing sanitary sewer system would result in or add to a violation of existing requirements prescribed by either the Santa Ana or San Diego Regional Water Quality Control Boards. The Initial Study/Mitigated Negative Declaration (IS/MND) identified the Moulton Niguel Water District (MNWD) collection system for treatment at existing regional treatment facilities and concluded that the project would not violate any water quality standards or waste discharge requirements, nor substantially degrade surface water or groundwater quality. In correspondence dated October 1, 2025, MNWD indicated that it will provide water, recycled water, and wastewater service to the proposed development and that a preliminary review suggests adequate water supply and sewer capacity are available to serve the project. The project remains subject to all applicable federal, State, regional, and local water quality regulations, including National Pollutant Discharge Elimination System requirements, implementation of the approved Water Quality Management Plan, and applicable Regional Water Quality Control Board regulations.

J. If the advisory agency approves or conditionally approves a tentative map which deviates from any standard of design as allowed by AVMC, the advisory agency shall make a finding that each such deviation has been individually considered and found to be justified based upon specific special circumstances. No deviations from the subdivision design standards are proposed as part of the Vesting Tentative Tract Map. Accordingly, no deviations require consideration or justification based on special circumstances, and this finding is not applicable.

Section 4. Findings for Site Development Permit SDP-2026-01001. Pursuant to AVMC 15.74.020 (Site Development Permits), the City Council hereby makes the following findings of fact and approves the Site Development Permit SDP-2026-01001, subject to the conditions of approval as set forth in Exhibit “A” and Project plans as set forth in Exhibit “B”, which are attached hereto and incorporated herein by reference.

A. Consistency with General Plan. The project is consistent with the general plan and any applicable specific plan. The Project with the General Plan 2128

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Amendment to Medium Density Residential is consistent with the goals and policies of the General Plan as listed below in that it incorporates landscaping aligned with the City Council-approved plant palette, emphasizing low-water, drought-tolerant species; features building materials, colors, and architectural design that are compatible with the surrounding residential communities; includes a development impact fee that a portion of which is consistent the City’s parkland ordinance; proposes three affordable housing units restricted to very low-income households, thereby enhancing housing diversity and affordability; and introduces rezoning to facilitate residential development that includes affordable units in support of the City’s housing objectives.  Policy COS-1.2 Reduce the amount of water used for landscaping and increase use of native and low water plants. Maximize use of native, lowwater plants for landscaping of areas adjacent to sidewalks or other impermeable surfaces.
 Policy COS-4.2 Encourage and maintain high-quality architectural and landscaping designs that enhance or complement the community’s visual character.
 Policy COS-7.5 Ensure that new development provides park land and/or improvements at a fair share ratio, pursuant to the City’s Parkland Ordinance.
 Goal H-1: Encourage a diversity of housing types and provide affordability levels within Aliso Viejo to meet the needs of community residents.  Policy H-1.1 Identify sites appropriate for the development of a variety of housing types and price ranges to meet the needs of all socioeconomic segments of the community through the disbursement of affordable units in projects.
 Policy H-1.2 Encourage through the use of density bonuses and rezoning to allow for residential development, development of affordable housing opportunities throughout the community, as well as development of housing for elderly and low- and moderate-income households near public transportation services.
 Policy H-1.4 Ensure that a portion of future residential development is affordable to low- and very-low-income households by designating certain sites as having the potential to be used for residential uses.  Policy H-3.8 Review existing zoning policies and explore zoning changes to facilitate the development of affordable housing.
 Policy LU-12.2 As a condition upon new development, require payment of park fees and/or dedication and provision of parkland, recreation facilities and/or multi-use trails that improve the public and private recreation system.

B. Consistency with Zoning Code. The land use and associated development conform to the permitted use provisions and development standards of this zoning code and is consistent with this code and any applicable specific plan.

The proposed zone change to Medium Density Residential, together with the 2129

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associated development, is compatible with surrounding land uses, providing a transition that complements the existing neighborhood character. The property is suitable for residential use based on its location, access, visual character, and topography, and existing infrastructure is adequate to support the proposed development. The Project includes requests for incentives, concessions, and waivers pursuant to California State Density Bonus Law (Government Code Section 65915). The Project provides three deed-restricted very low-income units, representing at least five percent of the total units, and therefore qualifies for consideration of the requested density bonus incentives and waivers. The requested modifications include a one-foot increase in building height, a reduction in common open space, reduced perimeter setbacks, and reduced minimum boundary landscaping standards. In addition, the Project qualifies for a reduced parking requirement under State Density Bonus Law. Based on the applicable density bonus parking ratio, the Project is required to provide a minimum of 130 parking spaces. The Project proposes 140 parking spaces, consisting of 116 private residential parking spaces within garages and 24 unenclosed guest parking spaces, including one ADAaccessible space. Accordingly, the Project exceeds the minimum parking requirement established under State Density Bonus Law. With these provisions, the Project conforms to the permitted use requirements and development standards of the zoning code and remains consistent with all applicable Specific Plan regulations.

C. Compliance with CEQA. Processing and approval of the permit application are in compliance with the requirements of the California Environmental Quality Act. An Initial Study (“IS”) was prepared for the project, which identified potentially significant environmental impacts. However, these impacts can be mitigated to less than significant levels through revisions and implementation of mitigation measures. As such, a Mitigated Negative Declaration (“MND”) was prepared and circulated for a 20-day public review period from August 28 through September 17, 2026, with distribution to the State Clearinghouse, public agencies, nearby property owners, and interested parties. One comment was received from the California Department of Transportation (Caltrans), and its recommendation regarding construction haul routes using the state route highway system has been incorporated as conditions of approval. The IS determined that the project would not result in significant impacts to most resource areas, and identified mitigation measures for biological resources, cultural resources, tribal cultural resources, and geology and soils, which are included in the Mitigation Monitoring Program and Conditions of Approval.

D. Architectural Design. Directly north of the site are established multi-family and single-family residential communities. The adjacent multi-family development, in particular, shares several defining characteristics with the Project, including similarly scaled buildings composed of six attached units. The architectural style is complementary, featuring stucco exteriors, tile roofing, wrought iron balconies, recessed entryways, and communal open space without private 2130

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driveways. The surrounding single-family tract homes also reflect a consistent architectural design, with comparable color palettes, exterior finishes, and material selections. The Project further enhances this compatibility through the inclusion of framed windows, some accented with faux shutters, as well as a mix of hip and gable roof forms, which reflects the roof styles found in nearby residences. The proposed Project consists of similar attached townhome units with comparable building massing, architectural features, private garages, guest parking, landscaped common open-space amenities as the recently approved 95 Argonaut development, further demonstrating architectural compatibility. Both projects are designed to transition former office properties to residential communities while maintaining architectural consistency with surrounding neighborhoods. Collectively, these design elements ensure compatibility with the surrounding development
E. Site Design. Based on the analysis provided in the Initial Study and supporting documentation, the Project will retain the existing single-entry driveway at the southern end of the site along Argonaut. The internal private roadway system designed to provide two-way access to residential garages and guest parking spaces, emergency access, hydrant placement has been reviewed and conceptually approved by both the Building Division and the OCFA. Each unit will include an enclosed private garage with dedicated space for trash bin storage. Approximately 9% of the site will be dedicated to open space, including a private park, shared yards, pedestrian walkways, and perimeter landscaping.

Perimeter fencing and exterior mechanical equipment will be screened with additional landscaping, and the site entrance will be enhanced with decorative paving, signage, and accent trees. Lighting throughout the site, including streetlights, bollards, and shade structures, will be designed with recessed, downward-facing fixtures to minimize light spill which are compatible with the designs of the surrounding residential communities.

F. Landscape Design. Project landscaping, including but not limited to the location, type, size, color, texture, and coverage of plant materials, has been designed so as to provide visual relief, complement buildings, visually emphasize prominent design elements and vistas, screen undesirable views, provide a harmonious transition between adjacent land uses and between development and open space, and provide an overall unifying influence to enhance the visual continuity of the project. The Project incorporates a landscape plan that enhances the overall visual continuity of the site and complements the architectural character of the development. Existing landscaped slopes and mature screening trees along the northern and western boundaries will be preserved, maintaining established landscape buffers adjacent to Glenwood Drive and Aliso Creek Road. The Project provides common open-space amenities, including a community garden, dog play area, shade structure, barbeque area, pedestrian walkways, and landscaped gathering areas. In addition, approximately 7,611 square feet of private yard area is provided for individual residential units, and preserved open-space 2131

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slope areas remain throughout the Site. Landscaping is also proposed around the exterior mechanical equipment and perimeter fencing to screen undesirable views. The site entrance is designed to create a welcoming and visually prominent focal point, enhanced with decorative paving, signage, and accent trees. The proposed landscaping aligns with the City Council-approved plant palette, emphasizing low-water, drought-tolerant species.

Section 5.Severability. If any provision of this Resolution or the application thereof to any person or circumstance is held invalid, such invalidity shall not affect other provisions or applications of this Resolution that can be given effect without the invalid provision or application, and to this end the provisions of this Resolution are severable.

The City Council hereby declares that it would have adopted this Resolution irrespective of the invalidity of any particular portion thereof.

Section 6. Location of Documents. The administrative record for the Project is maintained at City Hall located at 12 Journey, Suite 100, Aliso Viejo, CA 92656. The custodian of records is the City Clerk.

Section 7. Effective Date. This Vesting Tentative Tract Map 19489, Site Development Permit SDP-206-01001 shall not take effect unless and until General Plan Amendment 2026-01002, Zone Change ZC-2026-01001, and the Development Agreement DA-2026-01002 are each approved by the City Council and have become effective, and the associated Development Agreement is approved by the City Council and executed by both parties thereto.

Section 8. Execution of Resolution. The Mayor shall sign this Resolution and the City Clerk shall attest and certify to the passage and adoption thereof.

PASSED, APPROVED AND ADOPTED this 7th day of October 2026. __________________________
Max Duncan
Mayor
APPROVED AS TO FORM: ATTEST:

__________________________ __________________________
Scott C. Smith, City Attorney Maria Kendig City Clerk
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STATE OF CALIFORNIA )
COUNTY OF ORANGE ) ss.

CITY OF ALISO VIEJO )
I, Maria Kendig, City Clerk of the City of Aliso Viejo, California, DO HEREBY CERTIFY that the foregoing is the original of Resolution No. 2026-__ duly passed and adopted by the City Council of the City of Aliso Viejo at their regular meeting held on the 7th day of October, by the following roll call vote, to wit:

AYES:

NOES:

ABSENT:
___________________________

MARIA KENDIG, CITY CLERK
(SEAL)
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Exhibit “A”
Conditions of Approval
Case Nos. GPA-2026-01002, ZC 2026-01001, VTTM 19489, and SDP-2026-01001 General

1. Indemnification. The Applicant shall indemnify, protect, defend, and hold the city, and/or any of its officials (appointed or elected), officers, employees, agents, departments, agencies, and instrumentalities thereof, harmless from any and all claims, demands, lawsuits, writs of mandamus, and other actions and proceedings (whether legal, equitable, declaratory, administrative or adjudicatory in nature), and alternative dispute resolution procedures (including, but not limited to arbitrations, mediations, and other such procedures), judgments, orders, and decisions (collectively 'Actions'), brought against the city, and/or any of its officials, officers, employees, agents, departments, agencies, and instrumentalities thereof, that challenge, attack, or seek to modify, set aside, void, or annul, any action of, or any permit or approval issued by the city and/or any of its officials, officers, employees, agents, departments, agencies, and instrumentalities thereof (including actions approved by the voters of the city) for or concerning the project, whether such Actions are brought under the Ralph M. Brown Act, California Environmental Quality Act, Planning and Zoning Law, Subdivision Map Act, Community Redevelopment Law, Code of Civil Procedure Sections 1085 or 1094.5, or any other federal, state, or local constitution, statute, law, ordinance, charter, rule, regulation, or any decision of a court of competent jurisdiction. It is expressly agreed the city shall have the right to approve, which approval will not be unreasonably withheld, legal counsel providing the city's defense, and that Applicant shall reimburse city for any costs and expenses directly and necessarily incurred by the city in the course of the defense. The city shall promptly notify the Applicant of any action brought, and city shall cooperate with the Applicant in defense of the action.

2. Other Agency Approvals. The Applicant shall comply with all applicable requirements of outside agencies having jurisdiction, including but not limited to the local fire authority, water district, and any other local, regional, State, or Federal agencies.

3. Prior to approval of the Final Map or issuance of a grading permit, whichever occurs first, the Applicant shall provide documentation from applicable utility providers confirming the availability and capacity of water, sewer, electric, communications, and other required utility services necessary to serve the project.

4. Prior to issuance of a certificate of occupancy for the first residential unit, the Applicant shall submit a Solid Waste Management Plan demonstrating compliance with applicable State recycling and organics requirements, including provisions for the storage, collection, and handling of solid waste, recyclable 2134

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materials, and organic waste. Any required waste collection areas shall be screened and maintained in accordance with the Municipal Code.

5. Public Works. If applicable, the Applicant shall apply for and obtain encroachment permits or other permits from the Public Works Department for any work or placement within the public right-of-way.

Development Agreement and Vesting Tentative Tract Map

6. Prior to issuance of any permit, the Applicant shall execute the Development Agreement with the City. The Applicant shall comply with all terms and conditions of the agreement.

7. Payment of the full $2,057,651 fee amount shall be made to the City prior to the issuance of a building permit for the Project. No permit shall be issued until the City has received the full payment and confirmed compliance with all applicable fee requirements. The City shall have no obligation to issue any permit until and unless such payment is received in full, any delay resulting from non-payment shall be solely the responsibility of the Applicant.

8. The Applicant shall provide a minimum of 3 dwelling units on-site as for-sale housing, which shall be deed restricted to very low-income households. Each unit shall be designed and located in full compliance with the plans reviewed by the City Council on October 7, 2026. Prior to issuance of any permit, the Applicant shall execute the Density Bonus Housing Agreement as provided in the Development Agreement. The Applicant shall comply with all terms and conditions of the Density Bonus Housing Agreement and the Development Agreement.

Vesting Tentative Tract Map

9. Prior to approval of the Final Map or issuance of a permit, the Applicant shall submit a Fire Master Plan to Orange County Fire Authority for review.

10.Prior to approval of the Final Map, the property owners shall sign the ownership certification on the map. If an authorized person is to sign for an owner, the Applicant shall submit documentation of such authorization to the City for review and approval.

11.Utility lines, including, but not limited to, electric, communications, street lighting, and cable television, shall be placed underground. The Applicant is responsible for making the necessary arrangements with the utility companies for the installation of such facilities. Appurtenances and associated equipment such as, but not limited to, surface-mounted transformers, pedestal-mounted terminal boxes, meter cabinets, and concealed ducts in an underground system may be placed above ground within the street right-of-way where sufficient right-of-way width exists so as not to pose a serious hazard to pedestrian traffic.
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12.All lots shall be connected to a sanitary sewer system.

Construction

13.The approved project involves the demolition of an existing office building development and construction of a new 58-unit townhome complex with associated parking lot and open space amenities. The project shall be constructed and maintained in full compliance with the approved plans and specifications, including but not limited to all details regarding building height, setbacks, site layout, parking, circulation, architectural features, and other design elements, reviewed by the City Council on October 7, 2026. Any modifications or deviations from the approved plans shall require prior review and approval by the City pursuant to AVMC 15.74.110 (Modifications to discretionary permits).

14.The approved project shall comply with all applicable provisions of the Aliso Viejo Municipal Code, including but not limited to building codes and any conditions imposed as part of the approval process.

15.Prior to issuance of any permits, the Applicant shall submit and obtain City approval of a construction plan detailing the phasing and timing of demolition of the existing office building, site grading, infrastructure installation, landscape/open space installation and construction of the approved 58-unit townhome community.

All work shall proceed in accordance with the approved construction plan, and any substantive changes to phasing or timing shall require prior written authorization from the City.

16.Prior to issuance of any permits, the Applicant shall submit a proposed haul route for the transport of earth, materials, and equipment to and from the site. The haul route shall be reviewed and approved by the City to ensure public safety, minimize traffic impacts, and protect adjacent properties. No grading or excavation shall occur until the haul route has received written approval, and any subsequent modifications shall require prior authorization by the City.

17.Following completion of grading and prior to issuance of any building permits, the Applicant shall submit a pad certification prepared and signed by a licensed civil engineer or geotechnical engineer, verifying that all building pads have been graded in accordance with the approved grading plans and are suitable for the intended construction. The certification shall be reviewed and approved by the City prior to any construction.

18.Construction activities shall be limited to the hours of 7:00 a.m. to 8:00 p.m., Monday through Saturday. No construction shall occur on Sundays or on Federal holidays. Use of rock crusher on site is prohibited.
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19.Prior to issuance of any grading permit, the Applicant shall submit a final drainage report, including detailed drainage and hydrology calculations, for review and approval by the City Engineer. The final drainage report shall demonstrate consistency with the approved preliminary drainage concept and confirm that proposed drainage improvements adequately convey, treat, detain, and discharge stormwater in accordance with applicable City and County standards.

20.Prior to issuance of a precise grading permit, the Applicant shall submit to the Director of Public Works for review and approval, street improvement plans including drainage plans and hydraulic calculations prepared by a California Registered Civil Engineer.

21.Prior to grading or building permit issuance, the Applicant shall prepare and submit for approval a Project Specific Final Water Quality Management Plan (FWQMP) for the subject project. The F-WQMP shall be consistent with the approved Preliminary Water Quality Management Plan and in full conformance with the Technical Guidance Document.
a. The Final Water Quality Management Plan shall include a copy of the applicable final Conditions of Approval, complete and thorough contents for all attachments, and a copy of the draft construction plan set, including project-specific details for all proposed water quality systems. b. The Water Quality Management Plan site plan shall show all applicable features proposed in the project narratives, including all source control and structural BMPs, including but not limited to catch basins, catch basin filters, catch basin stencils, drainage swales, parking lots, buildings, pump facilities, trash enclosures, retaining wall locations, landscaped areas, areas not a part of the project, and the point of compliance. The site plan shall be included in the Operations and Maintenance Plan and shall identify all BMPs required to be maintained in perpetuity.
c. The Final Water Quality Management Plan shall: revise Section 3.4 to reflect all applicable impairments to Aliso Creek; revise Sections 4.1 and

4.3 to reflect the true proposed path of travel for on-site flows; revise Section

5.2 to accurately represent the proposed LID BMPs; and revise Section 6 to include all information necessary to accurately describe the proposed project.
d. The Operations and Maintenance Plan shall be revised to include all applicable source control and structural control BMPs, including the proposed pump, catch basin inspection and maintenance, and street sweeping. The Applicant shall remove any items that are not relevant to this project.
e. The Applicant shall revise the stormwater documentation to ensure consistency and accurate representation of the project’s impervious area, including reconciliation of the discrepancy between the SOHM report impervious area and the impervious area stated elsewhere in the Water Quality Management Plan.
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22.Prior to issuance of any permit, during all grading and construction activities, the construction contractor shall post a clearly visible sign at the project site boundary listing a contact name and telephone number.

23.At least ten (10) days prior to commencement of mass grading, demolition, or major earth-moving activities, the Applicant shall provide written notice to surrounding property owners and occupants describing the anticipated construction schedule, duration of activities, hours of construction, haul routes, and a project contact telephone number. Prior to issuance of any permit, the Applicant shall submit a copy of the written notice to the City for review.

24.Prior to building permit final of any unit, perimeter fencing shall be installed on two sides of the property as referenced in the approved plans. The use of chain link, barbed wire, razor wire or electrified fencing are prohibited.

25.Project identification sign is required. Prior to installation of this sign, the project name shall be approved by the City to ensure appropriateness, aid in identification for emergency services and to avoid duplication with other projects in the City.

Placement of any permanent and temporary signs may be permitted pursuant to AVMC Chapter 15.34.

26.Screening of Equipment and Facilities. Mechanical equipment, ground-mounted utility, mechanical, and other similar equipment shall be screened pursuant to AVMC 15.14.120 (Screening of Equipment and Facilities).

27.Landscaping shall comply with AVMC 15.62.060 (Landscaping and screening). All landscaping and common areas on site shall be maintained in perpetuity by the Applicant or an established homeowners’ association.

28.Prior to issuance of any demolition or grading permit, the Applicant shall submit a Construction Waste Management Plan for review and approval by the Director of Public Works. The plan shall identify methods for recycling, salvaging, and diverting construction and demolition debris generated by the project and shall comply with applicable City waste reduction requirements. The Applicant shall demonstrate a minimum diversion rate of 75 percent from landfill disposal.

29.During construction, the Applicant and its contractors shall protect all existing survey monuments. Any survey monument disturbed or destroyed during construction shall be replaced or reset by a licensed land surveyor in accordance with applicable State law and City requirements.

30.Prior to issuance of any grading permit, the Applicant shall prepare and implement a Storm Water Pollution Prevention Plan (SWPPP), if required by State law, and shall obtain coverage under applicable National Pollutant Discharge Elimination System (NPDES) permits. Documentation demonstrating compliance shall be provided to the Director of Public Works.
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31.The Applicant shall retain a Qualified SWPPP Developer (QSD) and Qualified SWPPP Practitioner (QSP), as required by the State Construction General Permit, to prepare and implement all stormwater pollution prevention measures during construction activities.

32.If project grading activities require the import or export of more than 500 cubic yards of material, the Applicant shall obtain approval from the Director of Public Works prior to commencement of hauling operations. Any required haul route plan shall identify truck routes, hours of operation, traffic control measures, and street maintenance responsibilities.

Temporary Use Permits

33.The temporary placement of a trailer, recreational vehicle or other relocatable building, or the temporary use of a permanent structure on an active construction or grading site to serve as a construction and/or guard office may be permitted subject to approval of a temporary use permit pursuant to AVMC 15.14.170 (Construction and Guard Offices).

34.Temporary model home complexes and real estate sales offices may be established subject to approval of a temporary use permit pursuant to AVMC

15.14.180 (Model Home Offices).

Permit Validity

35.Expiration. This approval shall expire and be of no further force or effect if:
a. The permit is not established within two years of the permit’s effective date or such other time period designated by the permit approval, by state law, or by this code; or
b. After establishment, the use or activity for which the permit was approved is discontinued or abandoned for a period of one year.

36.Time Extensions. Upon application before expiration of the period of validity, the City Council may grant or conditionally grant an extension to the period of validity for up to one year per extension if it finds that such an extension is justified by the circumstances of the original findings for the project can still be made with, if necessary, the imposition of conditions not originally imposed on the project. The filing of an application for extension shall stay expiration of the permit until action is taken on the time extension by the decision-making authority. No more than two one-year extensions may be granted or conditionally granted.

37.Revocation of discretionary permits. Any discretionary permit may be revoked by the original decision-making authority pursuant to the provisions of AVMC

15.74.120 (Revocation of Discretionary Permits).
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Orange County Fire Authority (“OCFA”)

38.Prior to building permit issuance, submit plans for review and approval of the following: underground piping for private hydrants and fire sprinkler systems, and fire sprinkler systems.

39.Prior to concealing interior construction, submit plan for review and approval of the fire alarm system.

Mitigation Measures
Biological Resources

45. MM BIO-1a: Nesting Bird Pre-construction Surveys If ground-disturbing or vegetation-removing construction activities or tree removal is proposed during the breeding/nesting season for migratory birds (February 1 through September 15), a qualified Biologist shall conduct pre-construction surveys for special-status birds and other migratory birds within the construction area, including a 300-foot survey buffer (where accessible), no more than three (3) days prior to the start of ground-disturbing activities in the construction area.

46. MM BIO-1b: Avoidance of Active Avian Nests If an active nest (i.e., occupied by eggs or fledglings) is located during pre-construction surveys or at any point during the construction phase of the proposed project, the City of Aliso Viejo shall be notified regarding the status of the nest. Furthermore, construction activities shall be restricted as necessary to avoid disturbance of the nest until the eggs or fledglings no longer are in the nest or a qualified Biologist deems disturbance potential to be minimal. Restrictions may include establishment of exclusion zones (no ingress of personnel or equipment at a minimum radius of 300 feet around an active raptor nest and a 50-foot radius around an active migratory bird nest) or alteration of the construction schedule.

Cultural Resources

47. MM CUL-1: Prior to the initiation of construction activities, all construction personnel conducting ground disturbance at the site shall be provided a Worker Environmental Awareness Program (WEAP) cultural resources “tailgate” training. The training shall include visual aids, a discussion of applicable laws and statutes relating to archaeological resources, types of resources that may be found within the project site, and procedures to be followed in the event such resources are encountered. The training shall be conducted by an Archaeologist who meets the Secretary of the Interior’s Professional Qualification Standards for archaeology. An Archaeologist who meets the Secretary of the Interior’s Professional Qualification Standards for archaeology shall conduct an updated survey of the site following demolition and exposure of native soils and prior to any project-related trenching or grading to check for the inadvertent exposure of cultural materials. This shall be followed by archaeological monitoring during the grading and trenching phase of the 2140

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proposed project. At the completion of these phases, archaeological monitoring shall be reduced to periodic “spot checks.” In the event exposed soils indicate cultural materials may be present, this may be followed by regular or full-time archaeological monitoring as determined by the Archaeologist.

48. MM CUL-2: In the event that buried archaeological resources are discovered during construction, operations shall stop within a 100-foot radius of the find and an Archaeologist who meets the Secretary of Interior’s Professional Qualification Standards for archaeology shall be consulted to determine whether the resource requires further study. The qualified Archaeologist shall make recommendations to the Lead Agency on the measures that shall be implemented to protect the discovered resources, including but not limited to excavation of the finds and evaluation of the finds in accordance with Section 15064.5 of the CEQA Guidelines. Potentially significant cultural resources consist of but are not limited to stone, bone, fossils, wood, or shell artifacts or features, including hearths, structural remains, or historic dumpsites. Any previously undiscovered resources found during construction within the project area shall be recorded on appropriate California Department of Parks and Recreation (DPR) forms and evaluated for significance in terms of CEQA criteria. If the resources are determined to be unique historic resources as defined under Section 15064.5 of the CEQA Guidelines, mitigation measures shall be identified by the monitor and recommended to the Lead Agency.

Appropriate mitigation measures for significant resources could include avoidance or capping, incorporation of the site in green space, parks, or open space, or data recovery excavations of the finds. The Lead Agency, along with other relevant or Tribal officials, shall be contacted upon the discovery of cultural resources to begin coordination on the disposition of the find(s).

49. MM CUL-3: In the event of the accidental discovery or recognition of any human remains, CEQA Guidelines Section 15064.5, Health and Safety Code Section 7050.5, and Public Resources Code Sections 5097.94 and Section 5097.98 shall be followed. If during the course of project construction, there is accidental discovery or recognition of any human remains, the following steps shall be taken: 1. There shall be no further excavation or disturbance of the site where human remains are discovered and/or any nearby area reasonably suspected to overlie adjacent human remains until the County Coroner is contacted to determine whether the remains are Native American and if an investigation of the cause of death is required. If the Coroner determines the remains to be Native American, the Coroner shall contact the Native American Heritage 2141

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Commission (NAHC) within 24 hours, and the NAHC shall identify the person or persons it believes to be the Most Likely Descendant (MLD) of the deceased Native American. The MLD may make recommendations to the landowner or the person responsible for the excavation work within 48 hours, for means of treating or disposing of, with appropriate dignity, the human remains, and any associated grave goods as provided in Public Resource Code Section 5097.98.

2. Where the following conditions occur, the landowner or his or her authorized representative shall rebury the Native American human remains and associated grave goods with appropriate dignity either in accordance with the recommendations of the MLD or on the project site in a location not subject to further subsurface disturbance:
a. The NAHC is unable to identify an MLD or the MLD failed to make a recommendation within 48 hours after being notified by the commission. b. The descendant identified fails to make a recommendation. c. The landowner or his authorized representative rejects the recommendation of the descendant, and mediation by the NAHC fails to provide measures acceptable to the landowner.

Geology and Soils

50. COA GEO-1a: In accordance with Municipal Code 13.08.170, Soil Engineering and Engineering Geology Reports, a soil engineering and engineering geology report shall be required for grading projects unless otherwise waived by the building official. The reports shall include information appropriate for the site including any information required by the building official. Recommendations included in the reports and approved by the building official shall be incorporated in the grading plans or specifications. Accordingly, prior to issuance of grading permit, the project applicant shall provide grading plans or specifications that include all recommendations from the proposed project’s September 26, 2025, Geotechnical Investigation prepared by Alta California Geotechnical, Inc., or from the latest geotechnical study for the proposed project.

51. COA GEO-1b: Prior to and during grading, all grading activities adjacent to the existing slopes along the western and northern boundaries of the site shall be observed by a licensed California Geotechnical Engineer or Certified Engineering Geologist, consistent with the requirements of Aliso Viejo Municipal Code Chapter 13.08 (Grading and Excavation Code). If geologic or geotechnical conditions associated with slope instability are encountered that differ from those described in the approved Geotechnical Investigation prepared by Alta California Geotechnical, Inc. (September 26, 2025), the project Geotechnical Consultant shall evaluate such conditions and prepare supplemental geotechnical recommendations, as necessary, in accordance with the California Building Code and California Geological Survey Special Publication 117A. Any supplemental recommendations or corrective measures shall be incorporated into the grading or construction plans and shall be subject 2142

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to review and approval by the City Engineer prior to continuation of grading in the affected area, consistent with the Aliso Viejo Municipal Code.

52. MM GEO-1: The project applicant shall enlist a qualified Paleontologist (meeting the standards of the Society of Vertebrate Paleontology [SVP]) to prepare a Worker Environmental Awareness Program (WEAP) presentation for construction personnel. It will include information on paleontological resources, laws protecting them, types of fossils that could occur at the project site, and protocol for unanticipated discoveries. In the event that fossils are discovered during construction, excavations within 50 feet of the find shall be temporarily halted or diverted. The contractor shall notify the qualified Paleontologist to examine the discovery. The qualified Paleontologist shall document the discovery as needed in accordance with SVP standards, evaluate the potential resource, and assess the significance of the find under the criteria set forth in CEQA Guidelines Section 15064.5. Based on the significance of the find, the qualified Paleontologist shall determine procedures to be followed before construction is allowed to resume at the location of the find. If, in consultation with the qualified Paleontologist, it is determined that avoidance is not feasible, the qualified Paleontologist shall prepare a Paleontological Resources Impact Mitigation Program (PRIMP) to outline salvage and recovery procedures. If deemed necessary by the qualified Paleontologist, the PRIMP shall include construction monitoring requirements as well. The PRIMP shall be submitted to the City for review and approval and the approved plan shall be implemented.

Hazards and Hazardous Materials

53. MM HAZ-1: Implementation of Asbestos-containing Material, Lead-based Paint, and Petromat Surveys Prior to Site Demolition Activities: Prior to the issuance of demolition permits, the proposed project shall retain a Qualified Environmental Professional to conduct asbestos-containing material (ACM), lead-based paint (LBP), and Petromat surveys. If ACM or LBP are identified in existing building materials or if asbestos is identified within any Petromat that is part of the existing parking lot, proper removal and disposal of the materials in accordance with applicable local, regional, State, and federal regulations would be required. In addition, the developer shall implement all appropriate engineering controls, work practices, and notification procedures to prevent exposure of workers and the public and shall prepare and submit all necessary compliance documentation to the City.

Tribal Cultural Resources

54. MM TCR-1: Retention of Qualified Archaeologist and Worker Training. Prior to the issuance of a grading permit by the City of Aliso Viejo, evidence shall be provided to the City that a qualified archaeologist meeting the Secretary of the Interior’s Standards for professional archaeology has been retained by the Applicant to conduct any required training, evaluation, or treatment of archaeological resources that might be encountered during implementation of 2143

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the project. Prior to the start of grading, the qualified archaeologist shall conduct cultural resources sensitivity training for all construction personnel.

Construction personnel must be informed of the types of archaeological resources that may be encountered, both prehistoric and historical, and of the proper procedures to be enacted in the event of an inadvertent discovery of archaeological resources or human remains. The Applicant must ensure that construction personnel are made available for and attend the training and retain documentation demonstrating attendance. This documentation shall be made available to the City upon request.

55. MM TCR-2: Native American Monitoring. A Native American monitor from or approved by the project's consulting Tribes (Juaneño Band of Mission Indians Acjachemen Nation – 84A and Juaneño Band of Mission Indians Acjachemen Nation – Belardes) shall be present during all earth-moving construction activities. The Native American monitor shall be given the opportunity to participate in the cultural resource sensitivity training. At least 30 days prior to issuance of grading permits by the City for the project site and any off-site improvements, a Native American Monitoring Agreement shall be developed between the Applicant and the consulting party. The Monitoring Agreement shall identify monitoring requirements, treatment of cultural resources, communication protocols in the event of an unanticipated discovery, and the roles, responsibilities, and authorities of the Native American Monitor. The Monitoring Agreement shall also detail protocols for treatment and final disposition of any Native American cultural resources, sacred sites, and human remains discovered on the site that the Native American Monitor shall implement in consultation and coordination with the Native American Most Likely Descendant, as identified by the NAHC. Discovery and treatment of human remains shall comply with State Health and Safety Code Section 7050.5 and Public Resources Code Section 5097.98.

56. MM TCR-3: Archaeological Resource and/or Tribal Cultural Resource Discovery and Treatment. In the event of the unanticipated discovery of archaeological or other cultural resources, whether discovered through Native American monitoring or not, all work activities in the area within approximately 100 feet of the discovery shall be halted or redirected until the discovery can be evaluated by a qualified archaeologist. Construction shall not resume until a qualified archaeologist has conferred with the City and, in the case of prehistoric archaeological resources and tribal cultural resources, the Native American monitor, on the significance of the resource. If the discovered archaeological resource and/or tribal cultural resource is significant, avoidance and preservation in place shall be the preferred manner of mitigation pursuant to Public Resources Code Sections 21083.2(b) and 21084.3. If preservation in place is infeasible and data recovery through excavation is the only feasible mitigation available, a Treatment Plan shall be prepared and implemented by a qualified archaeologist, in consultation with the City. The City and Applicant shall also consult with appropriate Native American representatives in 2144

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determining treatment for prehistoric or Native American resources. Any evaluation and treatment shall be supervised by an individual or individuals that meet the Secretary of the Interior’s Professional Qualification Standards.

57. MM TCR-4: Treatment of Human Remains. In accordance with California Health and Safety Code Section 7050.5, if human remains are found, the Orange County Sheriff’s Coroner shall be immediately notified of the discovery.

No further excavation or disturbance of the site or any nearby area reasonably suspected to overlie adjacent remains, approximately 100 feet or as determined by the project archaeologist, shall occur until the procedures set forth in this measure have been implemented. If the County Coroner determines that the remains are, or are believed to be, Native American, the Coroner shall notify the Native American Heritage Commission (NAHC) within 24 hours. In accordance with California Public Resources Code Section 5097.98, the NAHC must immediately notify those persons it believes to be the Most Likely Descendant (MLD) from the deceased Native American. The MLD shall complete their inspection within 48 hours of being granted access to the site. The designated Native American representative would then determine, in consultation with the property owner, the disposition of the human remains.

58. MM TCR-5: Native American Monitoring. The project applicant shall retain a Native American Monitor from or approved by the project's consulting Tribes (Juaneño Band of Mission Indians Acjachemen Nation – 84A and Juaneño Band of Mission Indians Acjachemen Nation – Belardes). The monitor shall be retained prior to the commencement of any ground-disturbing activity for the project at all project locations, including on-site and any off-site locations included in the project description or required in connection with the project.

Ground-disturbing activity shall include, but is not limited to, demolition, pavement removal, potholing, auguring, grubbing, tree removal, boring, grading, excavation, drilling, and trenching. A copy of the executed monitoring agreement shall be submitted to the lead agency prior to the earlier of the commencement of any ground-disturbing activity or issuance of any permit necessary to commence a ground-disturbing activity. A construction coordination meeting shall be conducted prior to the start of ground-disturbing work with the Qualified Archaeologist, Construction Contractor, and Tribal Representative(s). Tribal Cultural Resource monitoring shall be conducted during all initial ground-disturbing activities until both the Archaeologist and Tribal Monitor determine monitoring is no longer needed. If cultural materials, features, human remains, or artifacts are discovered, the applicable reporting, consultation, treatment, documentation, and respectful reburial or disposition procedures required by the IS/MND shall be followed. The Qualified Archaeologist shall submit a Final Monitoring and Mitigation Summary Report to the project applicant and appropriate CHRIS repository. The Lead Agency shall ensure that all measures are implemented, documented, and verified prior to and during construction activities, and records shall be maintained in the project file.
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Public Works
P1. Prior to any work being conducted within the City right of way, the Owner/Developer shall obtain all necessary encroachment permits from the Public Works Department. Separate deposit is required for plan check/inspection of encroachment permit.

P2. Prior to issuance of a Grading Permit, the Owner/Developer shall submit to the Director of Public Works for review and approval, street improvement plans including drainage plans and hydraulic calculations prepared by a California Registered Civil Engineer.

P3. Water Quality Management Plan. Prior to issuance of a grading permit, the Owner/Developer shall submit and obtain approval of a final project-specific WQMP consistent with the applicable local WQMP or BMP Design Manual and the San Diego Regional MS4 Permit, Order No. R9-2013-0001, as amended by Order Nos. R9-2015-0001 and R9-2015-0100, or the applicable successor order.

The WQMP shall address applicable low impact development, pollutant control, and hydromodification management requirements. The approved WQMP shall govern implementation and long-term maintenance of the project’s water quality features. The Owner/Developer shall implement its requirements and allow City verification of compliance.

P4. Prior to issuance of a construction or grading permit and before clearing, grading, or excavation, the Owner/Developer shall provide evidence of coverage under the State Water Resources Control Board Construction General Permit, Order WQ 2022-0057-DWQ, or the applicable successor order, when coverage is required. Evidence shall include the applicable Notice of Intent and Waste Discharge Identification number or other documentation accepted by the Public Works Director. The Owner/Developer shall maintain required coverage throughout construction and satisfy applicable permit termination requirements.

P5. Other Water Board Approvals. Before undertaking work requiring separate authorization, the Owner/Developer shall obtain all applicable Regional Water Quality Control Board and State Water Resources Control Board permits and clearances, including those applicable to grading, clearing, and grubbing. Copies shall be furnished to the Public Works Director before the affected work begins.

P6. Storm Water Pollution Prevention Plan. Where required by the Construction General Permit, the Owner/Developer shall have a Qualified SWPPP Developer prepare a Storm Water Pollution Prevention Plan (SWPPP) addressing potential pollutant sources, construction pollution prevention, and solid waste management. The SWPPP shall identify the design and placement of BMPs to prevent pollutants from entering the storm drain system. The 2146

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Aliso Viejo City CouncilOctober 7, 2026

Aliso Viejo City Council
October 7, 2026