Week 1:

Install seepage meters
Install mini-piezometers  and measure head difference between lake and groundwater
Check water levels of onshore piezometers.

Week 2:

Determine seepage rates
Repeat mini-piezometer installations/measurements

Purpose:
 To determine seepage rates at a groundwater-supplied lake.
 To determine in-situ permeability of sediments.
 To determine shallow head gradients.

Methods:

Seepage meter installation will be demonstrated.

Mini-piezometers

 The mini-piezometer is a piece of tubing with a screened end, that gets installed into the sediments.

Installation:
· The tube is cable-tied to the outside of the PVC.
· Push or hammer the PVC into the sediment approximately 30 cm.
· Attach the tubing with the syringe and very gently inject a small amount of water (to de-clog screen)
· If the level of water in the piezometer is higher than the lake level,just measure the difference.
· If you can’t see the level of water in the tubing, it’s below lake level.
· Take the other piece of tubing (on the other side of the “Y” ) and drop it into the lake.
· Use the syringe to pull up the water levels in both tubes so that you can measure the head difference. Be careful to avoid air bubbles in the tubing. Wait until the water in the sediment tube stops moving.
· Measure the difference.

Push in to 45 cm, measure head difference.
Push/hammer in to 60 cm, measure the head difference.
Repeat at 4 locations. Try to make a transect perpendicular to shore.

During the second week, we'll remeasure the transects to look at the variation in head with time.

What to turn in: (10 neatness points)

1. A description of methods used (10 points).
2. A site map showing the relative locations of the shoreline, seepage meters, and mini-piezometers. (10 points)
3. Data tables with raw data and calculated hydraulic gradients (30 points).  Here is one data table, here is another table, and here is a third table (It would help for you to neaten them).
4. Calculate the specific discharge, q, from your seepage meter measurements (10 points).
5. Using Darcy’s Law and the hydraulic gradient from the mini-piezometer closest to the seepage meter (use the shallowest measurement), calculate the vertical hydraulic conductivity of the sediments. (10 points)
6. (10 points) For your transects (one from each week), make cross sections of head values.
7. (10 points) During the second week, each group will provide the hydraulic head measurements from their transect to the other groups. So you'll have available:
· 4 transects of head from one week
· one transect (your group's) the second week
· a calculation of Kv

,Based on these values, discuss the pattern of fluid flow and it vertical, lateral, and temporal variability.

8. (10 points) Create a water budget for Lake Wauberg. Identify which components are unknown, and specify how you would a) roughly estimate and b) more accurately determine each value. To help answer this question, be sure to look around the lake (and look at maps) to evaluate inflows and outflows of water to the lake.