Chapter 3 Surface Water

Section 3 Hydrology and Surface Water Quality

WREP Sectional Replacement Project, Georgia

Environmental and Social Baseline Report

Hydrology and Surface Water Quality 1 August 2016

3.1 Introduction The majority of watercourses were surveyed in 2009, with the rivers Liakhvi and Supsa surveyed during 2011. This section of the Environmental and Social Baseline Report is organised as follows:

3.1 Introduction

3.2a Hydrology – all rivers1 except R Liakhvi and R Supsa

3.2b Hydrology – R Liakhvi2

3.2c Hydrology – R Supsa

3.3a Water Quality Baseline – all rivers except R Liakhvi and R Supsa

3.3b Water Quality Data – R Liakhvi and R Supsa.

The location of each of the water bodies was pre-programmed into a GPS unit, which was used by the Field Survey Team Leader to identify the sample locations.

Hydrological data was collected for each of the river crossings as follows:

• GPS location of crossing • Approx AM of crossing • Photo upstream and downstream • Width and depth of water flow • Width and depth of channel • Upstream catchment area • Downstream sensitive receptor and distance • Flow rate - approx. • Type of watercourse - natural/canalised natural/man-made irrigation.

Water sample collection followed one of the following two protocols depending on the prevailing conditions at the time of survey:

A) If there was safe and easy access to the edge of the body of water, and also there was sufficient recharge (i.e. the water was flowing fast enough that the sample would be representative, and not stagnant) then the sample was taken directly with the following process:

• The sampler remained at the edge of the water • A 1000ml sample container was held with opening pointing upstream, to allow

the container to be filled more quickly • Once the container was full, it was removed and the lid securely fastened on.

B) Where it was not possible to use the method above, then the sample was taken indirectly with the use of a disposable bailer using the following process:

• The sampler remained at the edge of the water • A length of string was securely attached to a disposable bailer and a weight was

attached to the bailer

1 This includes a number of rivers crossed by WREP that are no longer within the scope of the WREP-SR Project, yet the data is provided to facilitate understanding of background hydrological conditions. 2 Replacement of the R Liakhvi crossing is not part of the WREP-SR Project as it was undertaken during 2013/4. The data relating the R Liakhvi is included in the ESB as the river is one of the potential sources of hydrotest water.

WREP Sectional Replacement Project, Georgia

Environmental and Social Baseline Report

Hydrology and Surface Water Quality 2 August 2016

• The bailer was then cast a suitable distance into the body of water, where there was sufficient recharge for a representative sample to be taken

• The bailer was quickly retrieved, using the attached string, before it was able to disturb any sediment on the underlying bed

• Once the bailer had been retrieved the water was transferred to a 1000ml water sample container.

On each sample container the following information was recorded:

• A unique sample reference • Date • Location • Surveyor initials.

The water samples were stored in a cool box and transferred back to the laboratory on a daily basis, complete with a schedule for testing/chain of custody completed by the field surveyor.

The following information for each sample was noted on the surface water pro forma

• Unique sample reference • GPS reference • Photo Number • Description of sample • Observations regarding the body of water.