HomeMy WebLinkAboutPZ - Existing Surface Water Conditions v v
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❑AVI ❑ EVANS
AND ASSOC I ATES INC.
Existing Conditions
Irrigation water is being delivered to our site from an existing 12" PVC pipe that comes out of an existing
diversion box located at the NE corner of the site.The 12" PVC pipe is along our east property line and
heads southbound approx. 210' before it makes a 45' angle into our site.The pipe is capped and was
stubbed for flood irrigation purposes, but it is unknown if this pipe was ever used for flood irrigation.
Said pipe was installed by the adjoining neighbor(4079 W. Cherry Ln.), and currently only serves his
property (with the stub provided for our site).The exact location and inverts are unknown as this pipe is
buried and was only told its existence by the adjoining neighbor. Since the development of the adjoining
subdivisions along our West and South property lines,the historical irrigation ditch that continued down
the east property line,where it made a sharp 90°angle and headed west along our south property line
has been abandoned (reason why new pipe is capped). Currently,the site receives pressure irrigation
from an exiting well that seems to provide sufficient amount of water to irrigate the existing
landscaping.
Proposed PI System
With the abandonment of said ditch, a typical pressure irrigation system with wet well and intake box
cannot be constructed because there is no overflow ditch (or continuing irrigation pipe)to tie into. We
have explored the idea of installing a tall irrigation box at the SE corner of our site which could
potentially hydraulically stabilize the water in the wet well/intake box and avoid spillage (overflow), but
we would need a box that would be approx.4 to 5 feet tall (above existing ground)which is not a
feasible solution. Our only option would be to remove the 45 and continue the 12" down our east
property line, or from the 45 reduce the 12" line down to 6" and stub the pipe directly into a pad
mounted centrifugal pump system. We would install a 6" gate valve prior to the pump when
maintenance work needs to be done.With the limited supply of existing water rights,this method may
also be unachievable (explained below).
This development is eligible for only 0.12 Miners inches which equates to 1.08 gpm.A conservative PIRR
system design should be able to provide a minimum of 15 gpm at 50 psi to the most critical service
line in the system.This would require an additional 1.67 Miners inches to be purchased at a minimum
to run PIRR the system. If additional water rights are unable to be provided,then the use of the existing
well is the only option. If the well is to be abandoned,then city water is the only option (which will be
provided with backflow regardless).
9175 West Black Eagle Drive Boise Idaho 83709 Telephone: 208.900.9049 Facsimile: 503.223.2701