I would like to start circulating this idea now because kind of thing takes years to prove, negotiate and install. If we work aggressively starting now then we may be able to have a system deployed and a deal negotiated before the court ruling to reduce Atlanta's water extraction form Lake Lanier to 1970 levels takes effect.
may be a way for Atlanta to use
50 million gallons of water per day from Lake Lanier that nobody
downstream would object to. This approach is unlikely to be
challenged and would actually improve the quality of water released
downstream by improving oxygen levels.
The new process reduces evaporation by chilling the surface of the lake using cold water from deeper in the lake. If the water doesn't evaporate it can be used without reducing the amount of water flowing downstream or the lake level. Since it will also improve the quality of water being released this win, win for everybody. The government needs to negotiate a deal but this should be feasible especially if they only use 8 gallons out of every 10 they save.
Government studies have demonstrated that a 1C (1.8F) reduction in surface temperature can reduce evaporation by approximately 2,900 gallons per acre per day. Lake Lanier has 38,000 acres of surface area which adds up to a possible savings of 111 million gallons per day. Lake Lanier has very cold deep water in the summer. We use a small portion of this cold energy to chill the surface water which reduces evaporation while increasing circulation.
Our approach uses solar power and is as simple as dropping a bunch of self positioning buoys in the lake. No chemicals, No pipe network, No electric bills and precious little maintenance. Preliminary analysis indicates a cost between $100 and $600 per acre foot saved which is far cheaper than trying to replace the water with desalination.
Once validated there are finance companies who will pay to install the system and just charge the government for the water saved. This is a emerging as a favorite way to invest long term capital and means that people receive benefit with no up front government costs.
Lake Lanier and Atlanta Georgia are am interesting example opportunity is in Atlanta where a Federal court case has mandated that Atlanta reduce their water extraction from Lake Lanier to 1970 levels within 3 years. Once this technology proves out, it could deliver about 80 million gallons a day to Atlanta for an investment of about $320 million USD.
This would only work if the local and state government could negotiate permission to use the water they help retain in the reservoir. The total savings for the lake could be closer to 120 million gallons.
The 80 million usable was based on the assumption that 30 million would be left in the lake as part of the negotiated settlement. This is based on a 1C surface temp chilling for the entire lake. The entire lake may not be available for treatment so 50 million gallons usable at a lower cost is more likely.
This kind of water trading is already being done so there is ample precedent to allow a upstream city to fund downstream projects as long as the water delivered to downstream users nets out the same.
Lake Powell and Lake Mead on the Colorado would also be good candidates. The Las Vegas area is currently spending multiple billion $ for a controversial project to pipe water from surrounding counties so a 300 million investment for infrastructure installed in lake Mead would be a easy decision with the right kind of publicity.
Once validated at Lake Lanier the Georgia government will have new options including paying to install the same technology and process at other reservoirs downstream in Florida and Alabama. This can turn into a win, win because for every 100 gallons they help others downstream save they can negotiate a portion of those savings that they can extract from Lake Lanier. This type of water trading is already done on the Colorado River.