Water Quality Working Group

**[Lake Tahoe Interagency Monitoring Program (LTIMP)]{.underline}**

## Subcommittee

**Next LTIMP Meeting:**

**[WEDNESDAY February 5, 2003]{.underline}**

**@ [9:00 am to 12:00 pm]{.underline}**

[@ South Lake Tahoe City Council Chambers]{.underline}

# Meeting Minutes -- December 4, 2002

***[In Attendance (22 --20) affiliations):-]{.underline}***

Rita Whitney, TRPA\* Alan Heyvaert, TRG\*

Steve Patterson, EDAW Tom Lopes, USGS\*

Michelle Sweeny, NTCD\* Larry Benoit, TRPA

Vern Finney, NRCS Sue Norman, USFS

Michelle Kramer, WetLAB\* Gordon Seitz, San Diego State U.

Kim Melody, TRCD Chris Twomey, C2ME Engineering

Guy Burge, NTCD Kim Carr, CTC

Mark Palmer, High Sierra Lab/TRG Charlie Donohue, NV State Lands

Jason Kuchnicki, NDEP Rob Kuczynski, NDEP-BWQP

Sarah Tone, WasteNot Cindy Neisess, RCI

John Kobza, SEM\*\` Greg Kuczynski, Placer Co.

> \* - Attended previous meeting

The meeting was called to order, introductions were made, and the agenda
was reviewed, with no changes made.

**RING-TRUE Watershed Project, Incline Creek---**Rick Susfalk from DRI
gave a presentation on the results of this project funded through the
National Science Foundation and DRI. He provided a brief summary which I
have included here. His website address is
<http://inclinecreek.dri.edu/> if you didn't get it at the meeting.

**Incline Creek Watershed project, 2001-2002.**

**LTIMP Presentation on Dec 4, 2002 by Rick Susfalk (DRI).**

A goal of the Incline Creek Watershed Project
([http://inclinecreek.dri.edu](http://inclinecreek.dri.edu/)) is to
provide baseline data encompassing a wide selection of watershed
processes. The Project has established two intensive biogeochemical
study plots in a high elevation white fir (*Abies concolor*) stand and a
mid-elevation forest stand dominated by Jeffery pine (*Pinus jeffreyi*
Grev. and Balf.). Specifically, we are 1) monitoring vegetation health,
mortality, and aboveground nutrient fluxes; 2) assessing the nutrient
availability of soils; 3) measuring belowground nutrient fluxes and
water quality, including the effects that various native vegetation
species have on soil water quality; and 4) utilizing spatial and
temporal approaches to elucidating the stream transport of nutrients and
sediment through upland forests and urbanized areas.

During 2001-2002, nitrogen (N) and phosphorus (P) fluxes in surface
water (i.e. snowmelt, throughfall, and forest floor leaching) were
generally greater than the average 1.27 kg total N ha^-1^ yr^-1^ and
0.27 kg total P ha^-1^ yr^-1^ exported by Incline Creek at the outlet of
the undeveloped forest (near Tyrol Village). Upland forests acted as a
sink for nitrate plus ammonium (hereafter referred to as dissolved
inorganic nitrogen, DIN) and inorganic P (hereafter referred to as
orthophosphate, OPO~4~) deposited by snowmelt. At the white fir site,
the transfer of DIN (4.1 kg N ha^-1^ yr^-1^) and OPO~4~ (4.1 kg P ha^-1^
yr^-1^) by throughfall dominated the inputs by snowmelt (2.0 kg DIN
ha^-1^ yr^-1^, 0.2 kg OPO~4~ ha^-1^ yr^-1^). The forest floor acted as a
sink for nutrients, reducing the flux of N and P through the forest
floor by about 60%. Of the remaining nutrients that entered the mineral
soil, greater than 90% of DIN and OPO~4~ were removed from solution
within the upper 15 cm of soil.

Vegetation affected surface and soil solution chemistry. Dissolved
inorganic N (2.9 kg N ha^-1^ yr^-1^) and OPO~4~ (4.4 kg P ha^-1^ yr^-1^)
fluxes from the litter layer beneath snowbrush (*Ceanothus velutinus)*
were greater than those in adjacent pine forest floor by at least a
factor of three. Soil solution under bitterbrush (*Purshia tridentate*)
was notable because it had the highest average DIN (37 μg N L^-1^)
concentration of all non-riparian vegetation. This was consistent with
the high DIN (5.8 kg N ha^-1^ yr^-1^) and OPO~4~ (6.4 kg P ha^-1^
yr^-1^) releases that were 5 to 6 times greater than that found under
pine. Average soil solution DIN and OPO~4~ concentrations under riparian
mountain alder (*Alnus tenuifolia)* were 25 μg N L^-1^ and 8 μg P L^-1^,
compared to 17 μg N L^-1^ and 18 μg P L^-1^ under pine.

The spatial trends in water chemistry of Incline Creek and its
tributaries were surprisingly homogenous, with no clear delineation
between concentrations in undeveloped and urbanized stream reaches for
many nutrients. Deer Creek (the tributary to Incline Creek) was found to
have a different water chemistry than Incline Creek, as the Deer Creek
headwaters were found to be a high source of nitrate and chloride.
Phosphorus in this system was dominated by particulate P (PP; 0.071 mg P
L^-1^), coupled with low levels of inorganic P (0.007 mg OPO~4~ L^-1^)
that originated primarily from the undeveloped headwaters. Dissolved
inorganic N loadings were primarily from the lower urbanized reach of
Incline Creek, but did include significant seasonal snowmelt inputs from
both Deer Creek and the undeveloped headwaters of Incline Creek.
Inorganic N concentrations in stream water were reduced throughout the
watershed in the summer, presumably due to biological uptake. Nutrient
loadings from the undeveloped headwaters of Incline Creek were clearly
dominated by spring snowmelt, whereas some nutrients (e.g. TP, PP, TKN)
had greater instantaneous concentrations during thunderstorm events than
during snowmelt on Deer Creek and urbanized sections of Incline Creek.
Although Deer Creek contributes only a fraction of the flow to Incline
Creek most of the year, it can contribute significant nutrient and
sediment loadings during storm and snowmelt events.

**Wetlands Efficiency project, Village Green, Incline-** Nicole Beck of
Swanson Hydrology presented the results of the first year of sampling
for an EPA and Nevada State Lands funded study to determine the
effectiveness of natural and constructed wetlands in treating urban
runoff. The sites selected represent different types of wetlands in
various types of land use, sampled at several types of precipitation
events. The Eloise detention basin in South Lake Tahoe is a heavy
commercial and industrial area, the Northwood site samples at a road
culvert outlet to a grassy swale, in a rural residential setting at
Incline Village. The most interesting site turned out to be the samples
collected off the Village Green soccer and ball fields as it passes into
a

detention basin, and wetland treatment area. The SRP concentrations and
loading in the Village Green basin were generally two orders of
magnitude higher than at any of the other sites. In Marsh, at the very
first snowmelt, the pond already had significant algae blooms. While the
nitrogen species were very limiting in the pond, the phosphorus was
always in excess throughout the year. In October, TRPA and the
contractor, along with the Incline Village General Improvement
maintenance staff, removed as much of the algae and cattails as
possible. The theory is that removal of material will allow more uptake
in the spring, unfortunately funding for sampling has been exhausted and
additional sources are being sought. The new TRPA ordinance for
fertilizer management plans for turf areas over one acre may provide
some opportunity for sampling and projects on the contributions of
fertilized land in the basin.

**Round Robin-** The TRPA Project Review division has reviewed the
modification to the Qualified Exempt (QE) application for monitoring
related activities to determine in the appropriate findings of the Code
had been made. The main issue is related to land classified as 1b or
SEZ, where additional land coverage or disturbance is not exempt under
any circumstances. This could create a problem for instruments related
to measuring water which usually have to be located on land that tends
to be SEZ. However there are provisions in each MOU for the
jurisdictions, and in Chapter 20 for public service and water control
facilities which allow such activities for erosion control projects, and
programs necessary for environmental protection. For the last year the
modified QE has been used by various groups and agencies for these
monitoring installation but there has been no coordination at TRPA to
route copies of these approved applications to the person tracking
exempt activities under the MOU's (currently Jon Paul Kiel), nor has
this process been officially adopted by the Project Review Division.
Based on some of the applications submitted and a review by that
division, a revised QE application will be soon be available, although
probably not on the website.

The other major comment in looking at the stack of applications in the
past year was in the lack of any restoration or BMP plan or proposed
mitigation for construction, and in particular for the removal of the
installation. The checklist has a place for such a plan that so far most
applications have left blank or entered a N/A. This is an area that will
be clarified and detailed.

There was a brief discussion on the proposal by Tom Lopes from the USGS
to do nearshore sediment coring to relate to different land uses. There
were several members present who have done some work like this,
specifically Alan Heyvaert's PhD. Thesis, and the Gordon Seitz from San
Diego State. From their research the correlation of core data to land
practices cannot be reliably made