Correction to the RDOS Assistant Director, Terry Schafer comments on July 17, 2020.
There are 5 creeks not 3 feeding into Sportsman Bowl. No earthen dam was taken out of the Upper Twin Lake and this was not a one- time event.
On April 23, 2018 RDOS held a meeting of concern with Willowbrook and Sportsman Bowl already in flood. Horn Creek which feeds the Twin Lake waterway was just thawing so please do not blame Twin Lake and Lower Horn Creek (the overflow outlet of Twin Lake) for lower elevation flooding. The small earthen Dam on the Upper Twin Lake exists & belongs to the Nature Trust. It has been in place since 1949. The 206% of Normal Orofino Mt. snow pack was more than the waterway could handle. Horn Creek, Orofino Creek and also Myers (Park Rill) Creek each originate from different faces of Orofino Mt. & come together before Willowbrook.
Plugged, undersized culverts, sediment loading and development on flood plains exacerbated the flood. Kearns and Victoria Creek also join the 3 other creeks. There are 5 creeks feeding into the Myers Flat wetland and into Sportsman Bowl. Because the overflow outlet to Lower Horn Creek from Lower Twin Lake was closed by a rancher in 1951 and the creek bed filled in 1962, Twin Lake has a pump to release water over the so formed land bridge outlet, but it is only operated by permission from the Ministry.
There has been a historical 20 year water cycle and in the wet year cycle 1996 – 1999 there was a similar heavy snow pack but the Land Improvement District of Twin Lake (LNID) was able to divert ½ of the spring run-off water to a large hollow in the next White Lake Valley to save Twin Lake from flood. What happened down- stream?
Prior to 1996 Twin Lake management was by the rancher’s irrigation to a field called the Parc in DL 280.
With irrigation there is a 30% water loss to evaporation and a further water use for grass growth of 30%, thus decreasing the amount of water flowing to down gradient property. The flood of 2018 without restoring wetlands and a gate control outlet from Lower Twin Lake will happen again – it is definitely not a “one-off event”. Why pump away water needed in dry years to recharge the aquifer? Water should be slowed, spread and allowed to sink. Lets restore the lost wetlands.
Publisher was not at RDOS board for Terry’s comments. He was filling in for director Rick Knodel