[1.7.10] Preventing River Biome From Spawning

Hello,

Is there any way to prevent a biome from spawning? Specifically the river biome?

This is what I currently have:

	BiomeManager.coolBiomes.clear();
	BiomeManager.desertBiomes.clear();
	BiomeManager.icyBiomes.clear();
	BiomeManager.oceanBiomes.clear();
	BiomeManager.strongHoldBiomes.clear();
	BiomeManager.warmBiomes.clear();
	BiomeManager.removeSpawnBiome(BiomeGenBase.river);

I'm using a custom chunk manager, chunk provider, gen layer, and provider using a custom world type to override the first 3 and using reflection to replace the 4th.