Members ATtendance

VISITORS:  Bill French, interested citizen; Melinda Harper, Idaho Rural Water Association, Boise; Kathleen Warnick, interested citizen.

 

1)      Call to Order AND APPROVAL of april 18, 2002 Minutes
Jay Becker (Chair) called the meeting to order at 2:33 PM.  Minutes for the April 18, 2002 meeting were approved as edited.  Mark Workman asked that the assessments for FY 03 be revisited.  The discussion that followed indicated that the motion for continuing the assessment the same as last year may have been misunderstood.  The assessment motion will be revisited next meeting.  Kirkland will provide some example scenarios for various possible levels of support.

 

2)       Update on Water Movement through Palouse Basin Soils – 
Dr. Toby O’Geen, presented an overview of his recently completed Ph D on the topic of “Assessment of Hydrologic processes…in Palouse Soils”.   The precipitation gradient across the Palouse Basin from west to east, from low precipitation, 450 mm, to higher, 800 mm, significantly impacts the area soils and the rate that water moves vertically through them.  The rate of vertical water movement through western and central soils in the basin is much more rapid than through eastern soils because the western soils are weakly developed and, therefore, more permeable.  In the eastern portion of the Palouse Basin study area the soils are well developed, macropores are clogged and/or compacted by wetting and drying cycles.   As a result the vertical permeability of these soils is very low to water.  Once the water reaches the densified fragipan layer(s), almost all movement is horizontal or downslope parallel to the surface.


 
Highlights of the talk, slides and questions include the following:

a)      The Palouse loess, which was formed from uniform wind-blown particles over the last 2 milllion years, covers 75 percent of the Palouse landscape with 5 to 65 meters of heterogeneous soil.

b)      There are several to many buried soil horizons, called paleosols, in these thicknesses of loess that are easily observable in many of the roadcuts.  These paleosols are not homogenous or isotropic.  The physical properties of the paleosols differ from the top 2.5 feet of soil and old paleosols surface may differ significantly from the present surface. Depending on where in the basin they formed, these paleosols impact vertical water infiltration patterns through the soils differently.

c)      Two tracers, Cl and O18 were used to estimate the mass balance of water through the soil and the age of the pore water, respectively.

d)      Toby looked at both the Moscow-Pullman Basin, about 60,000 acres (or about 94 square miles) and the larger Palouse Basin, which is about 4 times that size. 

e)      He examined in detail three different catchments in the Palouse Basin, looking at three distinct locations, the ridge tops, the slopes and the valleys, in each.  The results for the west and central catchments were close enough to be able to aggregate these for most purposes.  The west and central soils were both silty loams comprised of about 65 percent silt and 22 percent clay.  Water is able to move through these soils at rates in the range of 3 to 6 centimeters per year.  The east catchment contained fragipan layers that produced perched water tables 6 to 8 months of the year.   Due to the fragipan which blocks essentially all downward movement of water,  downward migration of water is in thousands of years, if at all in soils similar to the eastern catchment soils.  Typically when the water reaches the fragipan it begins to move horizontally downslope until it reaches the valleys.  Some of the water leaves the catchment in the surface drainage.  It is unclear how much infiltration takes place in the catchment valleys.

f)       The differences in the catchment soils are due to the precipitation gradient over the area which goes from about 450 mm in the west to over 800 mm in the east.   The frequent wetting and drying cycles over thousands of years in the east moved clay particles downward and collapsed many of the macro pores to produce the very low permeable fragipan which is much like concrete and very hard to core through.

g)      Toby showed a slide of continuous perched water table weeping from above the fragipan along an entire road cut.  Where undisturbed the fragipan conducts the vertical infiltration parallel to the land surface into the valleys where at least some of the water flows away in the local surface drainage.  Eighty to ninety plus percent of the infiltrated water moves to the valley soils over the fragipan layer in the eastern basin soils that are similar to the catchment soils studied.

h)      Core samples of the valley soils indicated an active profile with multiple perched water tables but the extent of vertical water movement was unclear.  Toby estimated that the movement through these soils is 2 to 6 centimeters per year.

i)        Pore water samples taken from below the fragipan layer were essentially stagnated and 1000s of years old. 

j)        There were no dense layers in the western and central soil profiles that are comparable to the fragipan layer in the eastern catchment soils.  The residence time of water was much shorter.  The water in these soil profiles is essentially contemporary water.  [However, even though the western and central soils allow more vertical movement of water, they also have perched water tables, especially on northern slopes, and conduct water downslope according to the work of Diane Hopster while studying area springs.  LAK note]

k)      Using a GIS data base for area soils, Toby estimated the annual infiltration as 2.6 billion gallons of water per year for the Moscow-Pullman Basin.  [Consider the range on this from about 1 billion gallons to at least 5 billion gallons. LAK note]  This number came from matching area soils with the infiltration rates he had calculated for the different aspects in the three catchments studied.  This figure does not include movement of soil water into or out of area streams.

l)        Based on the above model, the majority of the infiltration through basin soils actually occurs in the west and central areas where the precipitation is significantly less than in the eastern portion of the basin.  This general conclusion contradicts current thinking that there is more infiltration in the eastern portion of the basin. 

m)   In the Q&A, Toby said that a top priority for follow up should be to understand better how the valley soil profiles work.  He also suggested using bomb tritium to get a better handle on the rate of water movement through the soil horizons.  Since some elevated nitrogen levels were observed, Toby suggested a follow up on water quality as it moves downward, especially in the valleys.

 

3)      Status on Proposed  Projects and Research Support

a)      Kirkland reported that both the Moscow Mountain runoff study and the water chemistry and microbiology study are moving forward.

b)     Minimal progress has been made toward identifying the best project which is acceptable to State of Idaho which also fits into the current sequence of studies for the Palouse Basin.  An attempt is being made to design an acceptable pilot connector well project for next fall after preliminary work is completed on the prerequisite projects.

c)      The Palouse Basin WRIA study is moving forward slowly at this time.  Rob Buchert anticipated a notice for the first organizational meeting to be sent out before the end of May.

4)      Xeriscape Poster Presentation – Moved to June meeting

5)      Elections for FY 03 to take Effect at July, 2002 meeting
Steve Busch nominated Mark Workman, the current vice-chair, for chair in the coming fiscal year.  Pete Grigas seconded the motion.  It was then amended to include the nomination of Steve Busch as vice-chair.  After some discussion over the fact that Steve Busch is planning to leave the Moscow City Council at the end of the calendar year, the motion was passed with no dissent. 

6)      OLD BUSINESS

a)      Renewal of Intergovernmental Agreement –
 Larry reported that PBAC received a draft MOU from Bill Thompson, the Latah County attorney, but there was a mistake in the communication in that the MOU provided was intended to replace the current draft intergovernmental agreement.  This was conveyed to Mr. Thompson and he has agreed to draft the MOU in the form of an appendix or addendum which will be part of the intergovernmental agreement signing.

b)     The 2001 Annual Report –
Larry handed out the newly printed copies of the 2001 Annual Report.  He pointed out that figure 15 was left out and there were a couple of grammatical errors but the presentation and content are good.  When Eddy Teasdale returns Larry and Eddy will figure out the best way to correct for the missing figure.

7)      REPORTS AND ANNOUNCEMENTS –

a)      Exposure in the Communities –      
In the absence of Tom Scallorn, the Moscow Water Department Supervisor, Larry reported that the Moscow Water Department observed National Water Week by inviting the public to tour the facility, view displays, ask questions and sign up to get water saving devices. 

b)     Pete Grigas reported that Parametrics, the WSU consultant working with WSU and Pullman on the early design for a conveyance system that would make possible the use of reclaimed water from the WWTP for irrigation and other uses, would be on the WSU Campus all day May 29^th.

c)      Kirkland reported that Eddy Teasdale had the draft copy of the Groundwater Management Plan update and he is out of town so the draft will not be available until the June 20^th meeting.

8)      NEW BUSINESS

a)      Kirkland reported that due to cutbacks at UI, he could no longer reserve the McClure 411 meeting room once a month.  Therefore, he proposed using one of the conference rooms at the Facilities Management facility west of the Kibbie Dome.  All agreed but asked for clear directions before the next meeting.

b)     Kirkland reminded the Committee that PBAC had agreed to provide Jim Osiensky with continued support for a ground water data collection tech once he had used what support he had in the OK Project funds.  Support is now needed for Dennis Owsley who took over from Landon Beck last fall.  Everyone agreed that PBAC needs to continue the improved data gathering.  Kirkland said Jim had spent $6000 out of the OK Project for part of a year and estimated the annual cost at $10,000 to $15,000.  Jim will provide a better estimate for the next meeting.

9)      NEXT MEETING DATE

The meeting was adjourned by consensus.

Respectfully Submitted,

Larry Kirkland

Note: these minutes are submitted in draft form and have not yet been approved by the Committee.