PP21-01 Zanjero Pass PrePlat Narrative

Zanjero Pass 
 
Preliminary Plat Narrative 
 
 
Northeast Corner of Citrus Road and Olive Avenue 
Maricopa County, Arizona 
 
Vicinity Map: 
 
 
 
 
 
 
 
January, 2021 
 
Prepared for: 
DR Horton  
c/o Patrick Brown 
20410 N. 19th Avenue, Suite 100 
Phoenix, Arizona 85027 
 
Prepared by: 
HilgartWilson 
2141 E. Highland Ave, Ste. 250 
Phoenix, AZ 85016 
Telephone: 602-730-3879 
Contact: Josh Robinson, P.E. 
 
Glendale Number 
Date Submitted 
Date Approved 
 
1/29/2021 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
Olive Ave.  
 
 
 
175th Ave. 
 
 173rd Ave 
 
Cheryl Dr.  
 
  Mountain View Rd.
  
Citrus Rd. 
Peoria Ave.

Page 2 
Zanjero Pass 
A Preliminary Plat for Zanjero Pass Phases 1-3 
 
Narrative Report Table of Contents 
 
Narrative: 
 
 
 
 
 
 
 
 
Page Number 
I. 
Project Description 
3 
II. 
Public Utilities and Services 
4 
1. Water Facilities 
1.1 Existing Water Conditions 
4 
1.2 Proposed Water 
4 
 
2. Wastewater Facilities 
2.1 Existing Wastewater Conditions 
4 
2.2 Proposed Wastewater 
5 
 
3. Dry Utilities 
5 
III. 
      Drainage  
1. Offsite  
5 
2. Onsite  
6

Page 3 
I. 
Project Description 
 
 
Zanjero Pass (the Project) is approximately 170.53 gross acres of vacant 
desert land located in Glendale and will be made up of three phases. The 
property was previously platted as “Zanjero Pass, Parcel 1 – 3, Phase 2 – 4” 
recorded in Book 979, Page 26 of the Maricopa County Recorder’s Office. 
Currently, the applicant (DR Horton), is processing a rezone concurrently with 
the preliminary plat. DR Horton is requesting to amend the approved 
Preliminary Planned Residential Development (PRD) zoning from R1-7 PRD, 
R1-8 PRD, and R1-10 PRD across the Project to R1-6 PRD (50’ Wide Lots), 
R1-6 PRD (45’ Wide Lots), and R1-10 PRD.  
 
 
Zanjero Pass is located within City of Glendale. The property is surrounded by 
the “Cortessa” development to the west and other vacant land and rural 
residential areas to the north, south, and east.  Phases 1, 2, and 3 of the 
property are generally bound by Olive Avenue to the South, 175th Avenue to the 
East, Cheryl Drive to the North, and Citrus Road to the West.  The property lies 
in Section 26 of Township 3 North, Range 2 West. 
 
 
The Project will be made up of three phases, all of which have varying zoning 
designations. Please see Table 1 below for breakdown. Phase 1 will consist of 
168 R1-6 PRD – 45’ wide lots. Phases 2 and 3 will follow shortly after and will 
be made up all three zoning designations, with a heavy emphasis on the larger 
lots along the perimeter of the Project. It is anticipated that the entire Project 
will be graded all at one time, with improvements and final plats broken up into 
three independent sets. Table 1 below summarizes the proposed lotting for 
each parcel. 
 
Table 1 – Zanjero Pass Project Summary 
Phase 
Number 
Zoning 
District 
Min. Lot 
Area (sf) 
Gross 
Area of 
Parcel 
Number of 
Units 
Gross 
Density 
(du/ac) 
1 
R1-6 PRD 45’ 
Wide Lots 
5,400 
45.85 
168 
3.66 
2 
R1-6 PRD 45’ 
Wide Lots; 
R1-6 PRD 50’ 
Wide Lots; 
and R1-10 
PRD 
5,400 
6,000 
10,000 
Respectively 
59.50 
202 
3.40 
3 
R1-6 PRD 45’ 
Wide Lots; 
R1-6 PRD 50’ 
Wide Lots; 
and R1-10 
PRD 
5,400  
6,000 
10,000 
Respectively 
65.19 
235 
3.61 
Total  
 
605 
3.55

Page 4 
II. 
Public Utilities and Services 
 
1. 
Water Facilities 
 
1.1 Existing Water Conditions 
 
The Project is located entirely within the EPCOR Water Service Area.  The 
existing water infrastructure immediately adjacent to the Project includes a 
16-inch water main in Citrus Road, a 12-inch water main along Olive 
Avenue, and an 8-inch water main in 175th Avenue.  The 12-inch water 
main in Olive Avenue begins at 175th Avenue and extends east to Cotton 
Lane.  The 8-inch water main in 175th Avenue reduces to 6-inches in size 
approximately 1,900 LF north of Olive Avenue. EPCOR is currently in the 
process of reviewing water plans for an additional 12-inch main that would 
connect the existing water lines between the intersection of Citrus Road 
and Olive Avenue and the intersection of 175th Avenue and Olive Avenue. 
It is anticipated that this 12-main will be installed prior to the Project 
starting wet utility construction. An additional stub will be provided off this 
newly constructed water main to serve the Zanjero Pass site. The Project 
receives water from the Clearwater Farms Booster Pump Station.  The 
Surface Water Treatment Plant is located at the northeast corner of 
Cactus Road and the Beardsley Canal. 
 
1.2 Proposed Water 
 
The Project will be served by an internal network of looped 8-inch 
waterlines. The looped water system infrastructure for the Project will 
make two connections to the existing 16-inch water main in Citrus Road, 
and one connection to the newly constructed 12-inch water main in Olive 
Avenue. It is not anticipated that any other connections will be required to 
meet adequate fire flow and peak demands. A looping system will be 
proposed with Phase 1 development, making connections to the existing 
water mains in Citrus Road and Olive Avenue. The third connection will be 
made with Phase 2 development.   
 
2. 
Wastewater Facilities 
 
2.1 Existing Wastewater Conditions   
 
Existing wastewater infrastructure immediately adjacent to the Project 
includes an 18-inch sewer main in Citrus Road, which was constructed to 
serve the Cortessa and White Tank Foothills developments.  This sewer 
main conveys wastewater flows southerly to Northern Avenue, where a lift 
station pumps the wastewater flows northerly to the City of Surprise 
wastewater treatment plant.  This sewer line is not available to convey 
sewer flows from the Project.  No other wastewater infrastructure exists 
immediately adjacent to the Project.  However, as part of the Loop 303

Page 5 
Corridor Group Joint Development Agreement, EPCOR will be the sewer 
service provider for the Project. As part of the Loop 303 Corridor Joint 
Development Agreement, EPCOR will extend the offsite sewer system to 
within a ½ mile of the site, at which then DR Horton will be responsible for 
the remaining portion. EPCOR is currently in the process of reviewing 
construction documents that will extend their wastewater service line to 
the intersection of Olive Avenue and 173rd Avenue. It is anticipated that 
this 12-inch diameter service line will be completed prior to the Project 
starting wet utility construction. 
 
2.2 Proposed Wastewater 
 
The Project will be served by an internal network of 8-inch gravity sewer 
lines.  The gravity sewer lines throughout the Project will generally route 
wastewater from each of the units to the southern boundary, where the 
onsite collection lines will have one point of connection to a proposed 8-
inch gravity sewer main in Olive Avenue. The 8-inch gravity sewer main in 
Olive Avenue will convey wastewater flows east towards the intersection 
of Olive Avenue and 173rd Avenue, where it will connect to the regional 
wastewater infrastructure that is being constructed by EPCOR. The 
phasing of the Project has been laid out in such a manner that the gravity 
sewer lines will not require any encroachment into latter phases.  
 
3. 
Dry Utilities  
 
Utility services to Zanjero Pass will include: phone service by Centurylink, 
natural gas service by Southwest Gas, and electric service by APS.  
Telephone cable is buried along Olive Avenue, 36 feet north of the 
centerline.  Southwest Gas has 4 inch and 2 inch diameter lines at the 
northwest corner of Olive Avenue and Cotton Lane. Electrical power will 
be provided from the overhead APS lines running along Olive Avenue.   
 
 
III. 
Drainage 
 
1.     Offsite 
 
The area surrounding the Property generally slopes to the south and east.  
Although the site is not subject to any regulatory floodplains, the Property 
is effected by minor sources of offsite drainage runoff along the north and 
west sides.  These flows are joined by stormwater runoff produced onsite 
as it is routed southeasterly toward the downstream (south and east) sides 
of the Property. These flows are generally conveyed in a series of broad, 
shallow washes.

Page 6 
2. 
Onsite 
 
The proposed onsite stormwater management concept for the Project 
consists of grading the lots to drain from the backyard to the streets, and 
the streets to drain toward a series of surface retention basins.  Street 
conveyance shall occur as either surface flow within the right-of-way or in 
a system of underground storm drains.  The retention basins will have 
sufficient capacity to retain runoff from the 100-year 2-hour storm event.   
Culverts and conveyance channels will be placed in locations where there 
is a need to convey offsite flows to their natural drainage paths.  The 
offsite flow approaching the northern and western boundaries will be 
routed around the site using the perimeter roadways or drainage corridors 
placed within the adjacent open space tracts.  Culverts will be constructed 
where the anticipated drainage crossings occur. 
 
100-year post development runoff at locations where flows exit the Project 
will not exceed the pre developed runoff thus preventing adverse impacts 
downstream of the Zanjero Pass property.  The ultimate site outfall will 
remain at the two southeastern corners of the property.  All finished floor 
elevations will be set a minimum of 12 inches above the high adjacent 
100-year water surface elevation and 14 inches above the emergency 
overflow elevation of any adjacent retention basin.  Drainage design will 
be conducted in accordance with all applicable City of Glendale and 
Maricopa County Drainage standards and regulations.