NorthPlatteBasinWaterSupplyandNeedsReport

• Basin Roundtable: North Platte
• Title: Water Supply & Needs Report for the North Platte Basin
• Date: 6/1/2006
• Author: CDM
• Basin Roundtables - Doc Type: Needs Assessment Documents

Section 9
Options for Meeting Future Water Needs
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20%

40%

Percent of Reusable Return Flow that is Exchanged

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80%

100%

Figure 9-5
Total Yield from Exchange of 1 AF of Consumable Water Based on Reuse to Extinction

Potential issues and conflicts involving reuse by
exchange include:

. There must be adequate exchange potential (physical
supply) available at the upstream point of diversion.

. The substitute supply (the reusable water that is used
to replace the water diverted by exchange) must be
suitable for downstream water uses as required by
statute.

. There may be water quality objections from
downstream users. The substitute supply may be of a
different water quality from what the downstream user
would have received absent the exchange. A water
court procedure allows these issues to be addressed.

. Storage may be needed to regulate year round
effluent return flows. The timing of return flows may
not match the times when there is exchange potential.
For example, winter effluent may need to be stored
for exchange to agricultural users during the irrigation
season.

. Previously unused reusable effluent historically
resulted in reduced or more junior river calls
controlling the river.

. As water availability decreases, M&I users are looking
to develop or expand the reuse of existing reusable
return flows via water rights exchanges. To the extent
these reusable flows have been returning to the
rivers, they have been used by downstream water
users.

CONI

9-16

. As reusable supplies that have been historically used
by downstream users are reused, river calls may
become more senior, impacting all users.

9.2.5.2 Non-potable Reuse

Non-potable reuse involves the capture and use of
legally reusable return flows for the irrigation of urban
landscapes or for industrial uses such as cooling or
process water. Since return flows from landscape
irrigation are hard to capture in one location, non-potable
reuse to date has involved the reuse of consumable
effluent discharged from wastewater treatment facilities.
The effluent undergoes additional treatment to meet non-
potable reuse standards. This treatment usually involves
filtration and additional disinfection.

As noted, it is infeasible to capture return flows from
landscape irrigation, though additional yield could be
achieved if the landscape irrigation return flow points and
amounts are identified and exchanged to upstream
points. A schematic illustrating non-potable reuse for
landscape irrigation is shown in Figure 9-6.

Figure 9-7 shows how the total yield from 1 AF of
consumable water based on the percent of the effluent
return flows that are used for landscape irrigation can be
increased. For example, if 50 percent of the effluent
return flows from an M&I use of consumable water were
reused for landscape irrigation the total yield realized
from 1 AF of consumable water is 1.25 AF.

S:\1177\Basin Reports\North Platte\S9_North Platte.doc