The NRCS calculated we have 1100ac of watershed going into our valley. There are two tanks before us on the neighboring property. Water flows in from due south, which is really different for the area in northern mid-west Texas outside of Eastland. Once those tanks overflow they spill into our portion of the valley which is the wetland. On a aerial photo from 1953 it was always a marsh created by a large dam where we dug a 1.5ac tank. The marsh is roughly 3ac. Knowing we would eventually have a lot of waterflow we had a 80x40x4ft sediment trap dug. The wetland is separated from the tank by a dirt road that various oil companies have reinforced with heavy gravel. There are two small tinhorns/culverts on one end. The tank was completed in February 2018 and overflowed in October. During really heavy rain about 5in over water flowed over the road from the wetland. The tinhorns continued to drain water for weeks. Very clear water was observed coming out of the wetland! Huge mosquitoes came out in force immediately. Dragonflies eventually helped but then winter set in and more rain came. Over the last 4+ months the tank overflowed altogether for well over a month. Fortunately we have a natural solid beautiful rock spillway. We just do not have the budget to make the tank larger and did not see the watershed when the property was purchased. Normal rainfall watershed is 50-60ac. The wetland had hundreds of "salt cedars" and the tank site was full of trees and brush. No longer. After typical warm winter weather, now the mosquitoes are horrible and I observed thousands of larvae in the 6-12in deep area that is most of the 3ac wetland. Going into the wet season I had to try something and started reading on here about forage ponds. Ding ding! Thanks Snrub! On 2/7/19 we added 5lbs of FHM and 100BG from the fish truck. I was advised of questionable fish truck genetics and will keep you posted on the BG growth rates. I do not plan on feeding them since their primary purpose is to control the wetland invertebrates. WHEN drought comes the deep area should concentrate them for capture and thus forage for the tank. After several weeks of no rain the wetland is still mostly 6-12in deep plus the deep area. The tank received 500 more BG and 10lb FHM on 2/7. 400BG, 200RES, 100HBG, 100CC and 13lb FHM were initially stocked 10/26 2018. 50 NLMB will be added in spring of 2020! After the last rain a large pothole formed in the center of the road above the tinhorns indicating they are rotten. Another immediate project is on the agenda. I will be adding a screen on the new larger tinhorns and likely a long screen where the wetland overflows during big events. See pic from 12/14/18. I do not hunt ducks but there are quite a few and they are enjoyable. Ideas for enhancing duck forage on a budget would be appreciated. I will continue provide updates as necessary!
As Vortex says, If any small fish esp Gambusia (aka mosquito fish) can get into the area where the mosquito larvae are growing the little fish will aggressively eat the very easy to catch and vulnerable small larvae. Gambusia due to their small size, prolific reproduction, and adaptability are often used in wetlands by Metro Parks to control mosquito larvae. Fish that grow larger size than Gambusia 2.5"+ in reality may not be the best choice in wetlands because larger fish will eat the larger dragonfly and damselfly larvae who eventually hatch and eat adult mosquitoes. Once the mosquito larvae hatch into adults, then air borne predators are your best defense.
